Chapter Chair/Editor: |
Clement
J. McDonald, MD |
Chapter Chair/Editor: |
Hans
Buitendijk |
Chapter Editor: |
Helen
Stevens |
Editor: Clinical Trials |
Susan
Rea Welch |
Editor: Product Experience |
J.
Marc Overhage, MD, PhD |
Editor: Product Experience |
Robert
Heiser |
Editor: Waveform Data |
Fritz
Friedhoff |
Editor: Waveform Data |
Ernie
Jacobs, MD |
Editor: Waveform Data |
Wayne
Tracy |
Editor: Waveform Data |
Terry
Lagerlund |
This
chapter describes the transaction set required for sending structured
patient-oriented clinical data from one computer system to another. A common
use of these transaction sets will be to transmit observations and results of
diagnostic studies from the producing system (e.g., clinical laboratory system,
EKG system) (the filler), to the ordering system (e.g., HIS order entry,
physician's office system) (the placer). However, the transaction set is not
limited to such transactions. Observations can be sent from producing systems
to archival medical record systems (not necessarily the order placer) and from
such medical record systems to other systems that were not part of the ordering
loop, e.g., an office practice system of the referring physician for inpatient
test results ordered by an inpatient surgeon. This chapter also provides
mechanisms for registering clinical trials and methods for linking orders and
results to clinical trials and for reporting experiences with drugs and
devices. These transaction sets permit the transmission of any kind of clinical
observations including (but not limited to) clinical laboratory results, the
results of imaging studies (excluding the image), EKG pulmonary function
studies, measures of patient status and condition, vital signs, intake and
output, severity and/or frequency of symptoms, drug allergies, problem lists,
diagnostic lists, physician and nursing history, physicals, progress notes,
operative notes and so on. An observation can be one of many data types. The
main ones are text, numbers and codes. This provides the flexibility needed to
transmit observations that are recorded as continuous values (e.g., glucose,
diastolic blood pressure), as categorical values, e.g., patient position
(sitting, reclining or standing), VDRL (reactive, weakly reactive or
nonreactive), or as text. An entire History and Physical could be transmitted
as an observation whose value is one large chunk of formatted text.
This chapter provides mechanisms for transmitting structured,
record-oriented reports. This means that individual observations are
transmitted as separate logical entities (objects), and within this entity,
separate fields are defined for identifying the observation, its values, its
units, normal ranges, etc., such that the receiving system can "understand,"
reorganize and/or react to the contents of these messages. Structured reports
are to be distinguished from text-oriented reports which can also be
transmitted via HL7 using the UDM message described in Chapter 2. The latter
are ASCII images of nonstandard printed reports intended for display to humans.
For practical purposes their contents are not understandable to the computer.
Observations may be transmitted in a solicited (in response to a query) or
unsolicited mode. In the solicited mode, a user requests a set of observations
according to criteria transmitted by the user. The sending system responds with
existing data to satisfy the query (subject to access controls). Queries do
not elicit new observations by the target system, they simply retrieve old
observations. (See Chapter 2 for full discussion of the query
transmission.)
The unsolicited mode is used primarily to transmit the values of new
observations. It is the mode used by producing services to return the values of
observations requested by an ordering system. A laboratory system, for
example, would usually send the results of an AM electrolytes to the ordering
HIS via the unsolicited mode. An intensive care system would send the blood
pressures to the same HIS by the same mode. Calling such transactions
unsolicited may sound like a misnomer, but is not. The placing service
solicits the producing service to make the observation. It could also (through
a query) solicit the value of that observation after it has been made.
However, such an approach would demand continuous polling of the producing
system until the result was produced. Using the unsolicited mode, the
producing service returns the value of an observation as soon as it is
available. The unsolicited mode can also be used to transmit new results to a
system (e.g., an archival medical record system) that did not order the
observation. The transactions that define these modes are more fully described
in Section7.2, "Trigger Events & Message Definitions."
Observations are usually ordered and reported as sets (batteries) of many
separate observations. Physicians order electrolytes (consisting of sodium,
potassium, chloride, bicarbonate) or vitals (consisting of diastolic blood
pressure, systolic blood pressure, pulse, and temperature). Moreover, tests
that we may think of as single entity, e.g., cardiac echo, usually yield
multiple separate measurements, e.g., left ventricular diameter, left atrial
diameter, etc. Moreover, observations that are usually reported as text (e.g.,
the review of systems from the history and physical) can also be considered a
set of separately analyzable units (e.g., cardiac history, pulmonary history,
genito-urinary history, etc.). We strongly suggest that all text clinical
reports be broken down into such separate analyzable entities and that these
individual entities be transmitted as separate OBX segments. Because many
attributes of a set of observations taken at one time will be identical, one
OBR segment serves as a header for the report and carries the information that
applies to all of the individual observations in the set. In the case of
ordered observations, the OBR segment is a "turn-around document" like the
manual request forms it replaces. It carries information about the order to
the producing service; a copy of the OBR with additional fields completed is
returned with the observations to the requesting service.
Not all observations are preceded by an order. However, all observations
whether explicitly ordered or initiated without an order are reported with an
OBR segment as the report header.
The major segments (OBR, OBX) defined in this chapter, their fields, and the
code tables have been defined in collaboration with ASTM E31.11 with the goal
of keeping HL7 observation transmission the same as ASTM E1238 in pursuit of
the goals of ANSI HISPP and the Message Standards Developers Subcommittee.
(Some sections of this chapter have been taken with permission directly from
the E1238-91 document and vice versa in pursuit of those goals).
The OBR segment provides information that applies to all of the observations
that follow. It includes a field that identifies a particular battery (or
panel or set) of observations (e.g., electrolytes, vital signs or Admission
H&P). For simplicity we will refer to the observation set as the battery.
The battery usually corresponds to the entity that is ordered or performed as a
unit. (In the case of a query, observation sets may be a more arbitrary
collection of observations.) The OBX segment provides information about a
single observation, and it includes a field that identifies that single
observation (e.g., potassium, diastolic blood pressure or admission diagnosis).
Both of these fields assume master tables that define coding systems (the
universe of valid identifying codes) for batteries and observations,
respectively. These tables will usually be part of the producing and sending
services application and (usually) include many other useful pieces of
information about the observation or battery. Segments for transmitting such
master file information between systems that produce and systems that use
clinical information are described in Chapter 8.
This Standard does not require the use of a particular coding system to
identify either batteries or single observations In the past, local
institutions tended to invent their own unique code systems for identifying
test and other clinical observations because standard codes were not available.
Such local code systems sufficed for transmitting information within the
institutions but presented high barriers to pooling data from many sources for
research or for building medical record systems. However, standard code systems
such as LOINC® and SNOMED now exist for many of these purposes, and we
strongly encourage their use in observation reporting. These codes can be sent
either as the only code or they can be sent along with the local historic code
as the second code system in a CE code.
In past versions of the HL7 standard, Appendix A to Chapter 7 presented
suggestions for constructing clinical codes from existing procedure code
systems such as CPT4. Appendix A is now part of the Implementation Guide and
contains LOINC® codes for most laboratory tests and many common clinical
variables and codes for reporting observations from the laboratory, 12-lead
EKG, cardiac echoes, obstetrical ultrasounds, radiology reports, history and
physical findings, tumor registries, vital signs, intake and outputs, and more.
The most recent version of the LOINC® database, which includes records for
more than 26,000 observations and includes codes, names, synonyms and other
attributes (such as the molecular weights of chemical moieties) for each
observation, is available from the Regenstrief Institute file server at
http://www.regenstrief.org/loinc/loinc.htm . Codes for
Neurophysiologic variables (EEG, EMG, Evoked potentials) are provided in
Appendix X2 of ASTM E1467. Some parts of this document (the discussion and
tables defining units, the discussion of the rules of mapping observations to
OBX segments, and some of the examples at the end of the chapter have been
copied (with permission) from ASTM E1238.
As is true throughout this Standard, the emphasis should be on the abstract
messages, defined without regard to the encoding rules. The example messages,
however, are based upon the HL7 encoding rules.
Following this Purpose and general information section, the remainder of this chapter is organized into four main subject areas; General, Clinical Trials, Product Experience and Waveform. Sections 7.1 to 7.4 document the trigger events, message definitions, segment definitions and examples for general observation reporting. Sections 7.5 to 7.8 include all information related to Clinical Trials. Sections 7.9 to 7.12 include all information related to Product Experience messaging, and sections 7.13 and 7.16 includes Waveform messaging information. Outstanding issues are listed in section 7.17
Person or service that requests (places order for) an observation battery, e.g., the physician, the practice, clinic, or ward service, that orders a lab test, X-ray, vital signs, etc. The meaning is synonymous with, and used interchangeably with, requestor. See ORC-2-placer order number, Section <IP_ADDRESS>, "Placer order number."
Person, or service, who produces the observations (fills the order) requested by the requestor. The word is synonymous with "producer" and includes diagnostic services and clinical services and care providers who report observations about their patients. The clinical laboratory is a producer of lab test results (filler of a lab order), the nursing service is the producer of vital signs observations (the filler of orders to measure vital signs), and so on. See ORC-3-filler order number, Section <IP_ADDRESS>, "Filler order number."
A
set of one or more observations identified as by a single name and code number,
and treated as a shorthand unit for ordering or retrieving results of the
constituent observations. In keeping with the mathematical conventions about
set, a battery can be a single observation. Vital signs, electrolytes, routine
admission tests, and obstetrical ultrasound are all examples. Vital signs
(conventionally) consist of diastolic and systolic blood pressure, pulse, and
respiratory rate. Electrolytes usually consist of Na+, K+, Cl-, and HCO3-.
Routine admission tests might contain CBC, Electrolytes, SMA12, and Urinalysis.
(Note that the elements of a battery for our purposes may also be batteries).
Obstetrical ultrasound is a battery made up of traditional component
measurements and the impression, all of which would be returned as separate
results when returned to the requestor. A test involving waveform recording
(such as an EKG) can be represented as a battery comprised of results of many
categories, including digital waveform data, labels and annotations to the
data, measurements, and the impression
The word battery is used in this specification synonymously with the word
profile or panel. The individual observation elements within a battery may be
characteristic of a physiologic system (e.g., liver function tests), or many
different physiologic systems.
A measurement of a single variable or a single value derived logically and/or algebraically from other measured or derived values. A test result, a diastolic blood pressure, and a single chest X-ray impression are examples of observations. In certain circumstances, tracings and images may be treated by HL7 as individual observations and sent as a single OBX. These include waveform data described in Section 7.15, "Waveform - Trigger Events & Message Definitions," and encapsulated data aggregates using the ED data type described in Section 2.8.14, "ED-encapsulated data," (which can represent actual images, audio data, etc.).
A
typed aggregate of fields (fields) describing one complete aspect of a message.
For example, the information about one order is sent as type of segment (OBR),
the information related to an observation is sent as another segment (OBX).
The segment in a message is analogous to a record in a database, and in
previous versions of the Standard we used record in place of the word segment.
We have changed the nomenclature to be consistent with HL7 and other standards
organizations in this version.
One specific attribute of a segment, for example, patient diagnosis, which may contain aggregates of fields further refining the basic attribute.
Some fields may contain many repeat fields. For example, the diagnoses field may contain many different diagnoses.
A field entry may also have discernible parts or components. For example, the patient's name is recorded as last name, first name, and middle initial, each of which is a distinct entity separated by a component delimiter (sub-subfield in ASTM E1238-94).
Narrative
reports from services such as Radiology usually consist of a number of
subcomponents (e.g., a chest X-ray report may consist of a description, an
impression, and a recommendation). Other studies, such as echocardiograms,
contain analogous components, as well as numeric observations (e.g., left
ventricular and diastolic diameter). Surgical pathology reports may contain
information about multiple specimens and reports: the anatomic source, the
gross description, the microscopic description, and a diagnostic impression for
each specimen.
The current Standard treats each component of a narrative report as a separate
"test" or observation. Just as a CHEM12 is transmitted as an order segment
(OBR) plus 12 OBX segments, a chest X-ray would be transmitted as an order
(OBR) segment plus three OBX segments, one for the description, one for the
impression, and one for the recommendations. Similarly, an EKG report would be
transmitted as an order segment (OBR), two OBX segments for the impression and
recommendation, and additional OBX segments for each EKG measurement, e.g. the
PR interval, QR interval, QRS axis, and so on.
We have defined code suffixes for constructing observation IDs for the common
components of narrative reports (see Figure 7-1). The observation identifier
for each such component is obtained by concatenating the observation battery ID
(the ID in OBR-4-universal service ID of the preceding OBR from any
coding system) with the appropriate suffix. The observation ID for a chest
X-ray impression, for example, would be the chest X-ray observation ID (if
CPT4, it would be 71020), a subcomponent delimiter, and the suffix, IMP, i.e.,
71020&IMP.
This same combining rule applies to other coding systems including local and
universal procedural codes (see Chapter 4). For example, if a local code for
EKG was E793, and the locally agreed upon designation for that local code was
EKG, the impression would be identified as E793&IMP^^99EKG.
Note: The "99EKG" in the 3rd component is included to indicate a local
code. The EKG's description, in this case, would be E793&GDT^^99EKG.
Although it is strongly discouraged, the sender and receiver may agree to allow
the omission of the observation ID component of a result segment when it is the
same as the observation ID of the preceding OBR. In this case, only the
ampersand and the suffix would have to be sent, e.g., &IMP or &REC, in
OBX-3-observation identifier of a result segment. The full code would
be assumed as the test identifier (recorded in the order segment) plus the
category identifier recorded in the observation segment.
Coded Results |
Suffix |
Type |
|---|---|---|
Diagnostic Impression |
IMP |
CE |
Recommendation |
REC |
CE |
Confirming procedures |
CNP |
CE |
Procedure Medication |
MED |
CE |
Anatomic Site |
ANT |
CE |
Device/Instrument |
DEV |
CE |
Serial # Device/Instrument |
SER |
ST |
Bulk Text Reports |
||
Gross Or General Description Of The Study |
GDT |
TX or FT |
Microscopic Or Secondary Description |
MDT |
TX or FT |
Technician's Comment |
TCM |
TX or FT |
Addendum Note |
ADT |
TX or FT |
Other |
||
Diagnosis Onset Date/Time |
ITM |
TS |
Diagnosis Resolution Date/Time |
RTM |
TS |
Comparison Study |
CMS |
CE |
Comparison Date/Time |
CMT |
TS |
Comparison Results |
CMR |
CE |
Comparison Change |
CMC |
CE |
Predicted Value |
PRD |
ST |
Percent Predicted |
PPR |
ST |
After Drug Observed |
AFD |
ST |
Predicted Value After Drug |
ADP |
ST |
Percent Predicted After Drug |
APP |
ST |
Timing Information |
TIM |
TS |
Channel Definition Data |
CHN |
CD |
Waveform Digital Data |
WAS |
NA or MA |
Waveform Annotation |
ANO |
CE |
The following subsections define each of the suffices except for the specialized waveform suffices, which are defined in Section <IP_ADDRESS>.2, "Maximum data value (NM)."
When
the suffix is IMP (OBX-3-observation identifier), the result is a
diagnosis or finding, stored as a CE data type. Multiple result segments with
an IMP suffix can be used if there are multiple parts to the study and each
have an associated diagnosis (for example, the awake and sleep portion of an
EEG). Each of these would have a different observation sub-ID. Multiple
result segments with an IMP suffix can also be used if there are separate
diagnoses corresponding to separate anatomic sites; in this case, the site for
each diagnosis (each result segment with an IMP suffix) must be specified by an
immediately preceding result segment with a suffix of ANT (see Section <IP_ADDRESS>,
"Anatomic site (ANT)"), which also has the same observation sub-ID. When
multiple distinct diagnostic impressions are being reported, for example,
mitral valve prolapse and aortic stenosis, each distinct impression should be
sent in a separate OBX segment. More than one code may be included within one
coded result segment, but only when such codes are modifiers of the principal
impression, e.g., to report additional detail about the finding, not to report
an entirely different finding. In this case, the OBX-5-observation
value field may repeat, with each instance or repetition specifying one of
the related coded impressions.
The coded data type for impressions does not mean that a reporting service must
actually code all such impressions. The diagnostic impression can be sent as
dictated text, but the text should be sent in the second component of the CE
data type without a code to distinguish it from code, i.e. it should be
preceded by a component delimiter, e.g., ^congestive heart failure.
When multiple separate text impressions are being reported, they should be
reported in separate OBX segments to indicate that they are distinct impressions.
When
the suffix is REC (OBX-3-observation identifier), the value is a CE
result, representing the reading physician's recommendations about repeat
testing, follow up or therapy. For example, when an ambiguous lesion result is
seen on a mammogram, the reading physician might recommend a repeat mammogram
in six months, or a needle biopsy immediately. The recommended procedures are
recorded as codes and/or text descriptions in the coded identifier structure.
If more than one follow up study is recommended, each such recommendation is
sent in a separate REC.
The confirming procedure OBX suffix identifies additional studies used to confirm the diagnosis reported in the IMP OBX. If, for example, electron microscopy was done to confirm a surgical pathology diagnosis, the identifier for electron microscopy OBX-3-observation identifier would be stored as the value field of an observation ID with a confirming procedure suffix. Confirming procedures are most important in surgical pathology reports. But they might also be used by services such as endoscopy, to record the fact that a biopsy, culture, etc., was taken during the procedure. If more than one confirming procedure was used, each is sent in a separate result segment with observation ID suffix CNP.
A
coded result segment with a suffix of MED (OBX-3-observation identifier)
indicates that the segment contained information about medication given as part
of the procedure -- contrast medication, medication intended to invoke a
physiologic response (e.g., to be used in stress testing) or premedication.
When patients receive more than one procedure medication, each medication
should be reported in a separate OBX medication segment. If the transmitting
system has codes available for medications, they would be recorded as the first
component of OBX-3-observation identifier. The name and/or the dosages
could be included in the second component of OBX-5-observation value.
A coded result segment with a suffix of MED (procedure medication) may also be
used to define a medication administered during recording of digital waveform
data or other extended diagnostic procedure, e.g., exercise test. These may be
displayed by the receiving system overlaid with the other events reported. The
procedure medication is assumed to pertain to and be associated with the data
recorded at the time specified in OBX-14-date/time of the observation,
of the OBX segment labeled with MED, when present.
Some diagnostic studies include observations about more than one anatomic site within one report. If, for example, a patient had an appendectomy incidental to gallbladder surgery, the pathologist's assessment of both specimens would usually be included under a single specimen number in one report. Each distinct anatomic site would be reported as a separate OBX segment with a suffix of ANT (OBX-3-observation identifier). More than one coded anatomic location may be included within a single OBX segment only when such additional codes are used to construct an identity for a single site. In this case only, the OBX-5-observation value field may repeat, with each instance or repetition specifying one of the related locations. Each OBX segment with an ANT suffix could be followed by one or more OBX segments with an IMP or other suffix to transmit the diagnostic impression(s) associated with the anatomic site. These impressions or recommendations would be associated with a single anatomic site via a common observation ID.
When required, the instrument or device which generated an observation can be transmitted as an additional result of the study. In this case, the suffix of OBX-3-observation identifier is DEV. Examples include: an automated instrument in the laboratory; an imaging device and model number in radiology; or an automatic blood pressure machine on the ward. The device is specified as a coded entry in anticipation that these identifiers could be specified as codes. Initially, we expect that most of the information about devices will be transmitted as text in the second component of the CE identifier.
Vendor's serial number of the device which generated the observation.
The general description suffix identifies the description component of a diagnostic study. In the case of anatomic pathology, it applies to the macroscopic (gross) description of the specimen. If the description consists of multiple paragraphs, the paragraphs should be separated by repeat delimiters so that the receiving computer can display them as paragraphs. It will not be necessary to include a description segment for a report when the impression segment says it all, e.g., for normal studies or studies such as EKG, whose reports are traditionally terse.
For most studies, a secondary description will not be needed. In the case of surgical pathology, however, the microscopic description is a separate part of the report. It describes the histology as seen through the microscope. The microscopic description will be sent in a segment with the suffix MDT in OBX-3-observation identifier. If the microscopic description consists of multiple paragraphs, the paragraphs should be separated by repeat delimiters so that the receiving computer can display them as paragraphs.
This is free text stored in a result segment whose OBX-3-observation identifier has a suffix of TCM for technician comment. It is used to record information about technical performance of the procedure, usually recorded by the technician.
Use to report information that is added as an addendum after the original dictation and sent as a separate labeled section of the report.
Use to record the date-time that a problem was first perceived to exist.
Use to record the date-time that a problem became inactive, i.e., the problem was cured or remitted.
When the reader of a diagnostic report compares the results for the current study with those of a previous study, this suffix allows them to report the nature of the comparison study as a separate result, i.e., an OBX segment with a segment whose observation ID has a suffix of CMS. Ordinarily, this would not be required because the observation ID in the other comparison OBXs would identify the test, if any of the other comparison values were transmitted.
When the reader of a diagnostic procedure compares the current results with a previous study, this suffix allows them to report the date-time of the previous study (time optional) as a separate result within the current report.
When the reader of a diagnostic procedure compares the current results with those of a previous study on the same patient, this suffix allows them to report the results (impression) of the previous study as a discrete result within the current report.
When
a diagnostic service reports a comparison between the current and a previous
study, this suffix is used to report the degree of change (e.g., much worse,
worse, minimal worsening, no change, slightly better, better, much better,
returned to normal) as a separate result within the report.
In current dictation, information about comparison is usually contained in the
descriptions of the study. The provision of the comparison suffixes listed
above do not imply a requirement to send this information as separate
components. The comparison variables are only meant to be enabling. When a
system would like to transmit them as discrete report components, these
suffixes give them the option.
When an observation has a predicted value as is the case for many spirometry tests, this suffix identifies the predicted observation as distinguished from the actual observation. The AS4 code for forced vital capacity is 94010.1 (see the HL7 Implementation Guide). The predicted forced vital capacity would be 94010.1&PRD.
This is a computed observation = (actual observation)/(predicted observation. For forced vital capacity the percent predicted would be identified as 94010.1&PPR.
An observation might be taken before and after a drug is given. This occurs especially in Spirometry. The predose observation is identified by the base ID. The post drug measure is identified by the AFD suffix. Using the AS4 base code for the forced vital capacity the post drug result would be identified by 94010.1&AFD.
The post drug predicted value is identified by the suffix, ADP. Following the pattern of the above example, it would be 94010.1&ADP.
The percent predicted after drug is identified by applying the suffix, APP to the base code - 94010.1&APP if using the AS4 code for forced vital capacity.
This suffix is used only for transmitting waveform data. It is fully described in Section <IP_ADDRESS>.
This suffix is used only for transmitting waveform data. It is fully described in Section 7.16.4.
This suffix is used only for transmitting waveform data. It is fully described in Section 7.16.5.
This suffix is used only for transmitting waveform data. It is fully described in Section 7.16.6.
The recently introduced LOINC® codes (See Figure 7-2 for full information) may be more useful to many users. Code system information, including LOINC®, has been moved from Appendix 7A to the Implementation Guide.
Various
fields of data type CE which are used in segments defined both in the current
chapter and other chapters, are used to transmit information about diagnoses,
observation results, procedures, health outcomes, and drugs administered.
Figures 7-2 and 7-3 (which were located in Chapter 2 in previous versions) list
some common coding schemes for these types of information. The values in the
second column of the table would be used in component 3 (and optionally,
component 6) of a CE field to identify the coding scheme used.
Refer to section 7.18.1 for the contents of the User
-defined
Table
0396 - Coding system.
The triggering events that follow are all served by the ORU (Observational report - Unsolicited) or the ORF (Observational Report Response) messages in combination with ACK and QRY. Each triggering event is listed below, along with the messages exchanged, and the segments that comprise the messages. The notation used to describe the sequence, optionality, and repeating of segments is described in Chapter 2, "Format for defining abstract messages."
The
OUL message is designed to accommodate the laboratory processes of laboratory
automation systems. The ORU message is still fully supported by HL7 for
transmitting laboratory results to other systems.
With the type (OBX) defined in this chapter, and the OBR defined in Chapter 4,
one can construct almost any clinical report as a three-level hierarchy, with
the PID segment defined in Chapter 3 at the upper level, an order record (OBR)
at the next level and one or more observation records (OBX) at the bottom.
One result segment (OBX) is transmitted for each component of a diagnostic
report, such as an EKG or obstetrical ultrasound or electrolyte battery.
The CTD segment in this trigger is used to transmit temporary patient contact
details specific to this order.
ORU^R01 |
Unsolicited Observation Message |
Chapter |
|---|---|---|
MSH |
Message Header |
2 |
{ |
||
[ |
||
PID |
Patient Identification |
3 |
[PD1] |
Additional Demographics |
3 |
[{NK1}] |
Next of Kin/Associated Parties |
3 |
[{NTE}] |
Notes and Comments |
2 |
[ |
||
PV1 |
Patient Visit |
3 |
[PV2] |
Patient Visit - Additional Info |
3 |
] |
||
] |
||
{ |
||
[ORC] |
Order common |
4 |
O BR |
Observations Report ID |
7 |
{[NTE]} |
Notes and comments |
2 |
[CTD] |
Contact Data |
11 |
{ |
||
[OBX] |
Observation/Result |
7 |
{[NTE]} |
Notes and comments |
2 |
} |
||
[{FT1}] |
Financial Transaction |
6 |
{[CTI]} |
Clinical Trial Identification |
7 |
} |
||
} |
||
[DSC] |
Continuation Pointer |
2 |
ACK^R01 |
Acknowledgment |
Chapter |
|---|---|---|
MSH |
Message header |
2 |
MSA |
Message acknowledgment |
2 |
Note:
The ORC is permitted but not required in this message. Any information
that could be included in either the ORC or the OBR must be included in the OBR
on reporting. Notice also that the ORU (and the QRY) messages accommodate
reports about many patients.
Many report headers (OBR) may be sent beneath each patient segment, with many
separate observation segments (OBX) beneath each OBR. Note segments (NTE) may
be inserted after any of the above segments. The note segment applies to the
entity that immediately precedes it, i.e., the patient if it follows the PID
segment, the observation if it follows the OBR segment, and the individual
result if it follows the OBX segment.
*
This message was designed to accommodate laboratory automation systems. It
permits the communication of the following kinds of information in addition to
the results themselves: relation of the analysis results to a particular
container with patient sample (SAC segment),
* relation of the analysis results to a particular container with QC sample and
the lot and manufacturer information about this sample (SAC-SID segments),
* basic identification data (lot, manufacturer, etc.) of the reagents and other
substances involved in the generation of analysis results (TCD-SID
segments).
If the results are for QC specimen container, then the patient related segments
(e.g., PID, PD1, PV1, PV2) are optional.
Refer to Chapter 13 Laboratory Automation for examples of usage.
OUL^R21^OUL_R21 |
Unsolicited Laboratory Observation Message |
Chapter |
|---|---|---|
MSH |
Message Header |
2 |
[NTE] |
Notes and Comments |
2 |
[ |
||
PID |
Patient Identification |
3 |
[PD1] |
Additional Demographics |
3 |
[{NTE}] |
Notes and Comments (for Patient ID) |
2 |
] |
||
[ |
||
PV1 |
Patient Visit |
3 |
[PV2]] |
Patient Visit - Additional Information |
3 |
] |
||
{ |
||
[ |
||
SAC |
Specimen Container Details |
13 |
[SID] |
Substance Identifier |
13 |
[{OBX}] |
Additional Specimen Characteristics |
7 |
] |
||
[ORC] |
Common Order |
4 |
OBR |
Observation |
7 |
[{NTE}] |
Notes and Comments (for Detail) |
2 |
{ |
||
[OBX] |
Observation Result |
7 |
[TCD] |
Test Code Detail |
13 |
{[SID]} |
Substance Identifier |
13 |
[{NTE}] |
Notes and Comments |
2 |
} |
||
[{CTI}] |
Clinical Trial Identification |
7 |
} |
||
[DSC] |
Continuation Pointer |
2 |
The
query response format options are described in chapter 5, Section 5.2.4
"Response format".
The QRD segment is defined in Chapter 5 Section <IP_ADDRESS>, "QRD - original style
query definition segment." The Query Result Level field of the QRD determines
the amount of data requested.
The QRF segment is defined in Chapter 5, Section <IP_ADDRESS>, "QRF - original
style query filter segment."
The subject filters contained in the QRD and QRF segments are defined by local
agreement between the inquiring system and the ancillary system.
The Set ID fields in the various segments (including PID) are used to count the
number of segments of one kind transmitted at one level of the hierarchy.
The CTD segment in this trigger is used to transmit temporary patient contact
details specific to this order.
QRY^R02^QRY_R02 |
Query |
Chapter |
|---|---|---|
MSH |
Message Header |
2 |
QRD |
Query Definition |
2 |
QRF |
Query Filter |
2 |
ORF^R04^ORF_R04 |
Observational Report |
Chapter |
|---|---|---|
MSH |
Message Header |
2 |
MSA |
Message Acknowledgment |
2 |
QRD |
Query Definition |
2 |
[QRF] |
Query Filter |
2 |
{ |
||
[ |
||
PID |
Patient ID |
3 |
[{NTE}] |
Notes and Comments |
3 |
] |
||
{ |
||
[ORC] |
Order common |
|
OBR |
Observation request |
7 |
{[NTE]} |
Notes and comments |
2 |
[CTD] |
Contact Data |
11 |
{ |
||
[OBX] |
Observation/Result |
7 |
{[NTE]} |
Notes and comments |
2 |
} |
||
{[CTI]} |
Clinical Trial Identification |
7 |
} |
||
} |
||
[ERR] |
Error |
2 |
[QAK] |
Query Acknowledgement |
5 |
[DSC] |
Continuation Pointer |
2 |
The full definitions of many segments required for reporting clinical observations are included in other chapters. The patient identifying segment (PID) is provided in Chapter 3. The NTE segment is in Chapter 2.
In
the reporting of clinical data, the OBR serves as the report header. It
identifies the observation set represented by the following atomic
observations. It includes the relevant ordering information when that applies.
It contains many of the attributes that usually apply to all of the included
observations.
When a set of observations is ordered, the order message contains an OBR
segment. However, observations can be collected and reported without an
antecedent order. When observations are reported, the report message also
includes one or more OBR segments. So,
the OBR segment is like a turn-around document. Some fields in the OBR segment
apply only to the ordering message and some to the reporting message. To those
familiar with healthcare procedures, these should be obvious from their names
(e.g., transcriptionist or principal result interpreter could only apply to the
reporting phase). However, we have also flagged them in Figure 7-4 to indicate
whether placer, filler, or both may send data in a given field.
SEQ |
LEN |
DT |
OPT |
RP/# |
TBL# |
ITEM # |
ELEMENT NAME |
|---|---|---|---|---|---|---|---|
1 |
4 |
SI |
O |
00237 |
Set ID - OBR |
||
2 |
22 |
EI |
C |
00216 |
Placer Order Number |
||
3 |
22 |
EI |
C |
00217 |
Filler Order Number |
||
4 |
250 |
CE |
R |
00238 |
Universal Service Identifier |
||
5 |
2 |
ID |
X |
00239 |
Priority - OBR |
||
6 |
26 |
TS |
X |
00240 |
Requested Date/Time |
||
7 |
26 |
TS |
C |
00241 |
Observation Date/Time # |
||
8 |
26 |
TS |
O |
00242 |
Observation End Date/Time # |
||
9 |
20 |
CQ |
O |
00243 |
Collection Volume * |
||
10 |
250 |
XCN |
O |
Y |
00244 |
Collector Identifier * |
|
11 |
1 |
ID |
O |
0065 |
00245 |
Specimen Action Code * |
|
12 |
250 |
CE |
O |
00246 |
Danger Code |
||
13 |
300 |
ST |
O |
00247 |
Relevant Clinical Info. |
||
14 |
26 |
TS |
C |
00248 |
Specimen Received Date/Time * |
||
15 |
300 |
CM |
O |
0070 |
00249 |
Specimen Source * |
|
16 |
250 |
XCN |
O |
Y |
00226 |
Ordering Provider |
|
17 |
250 |
XTN |
O |
Y/2 |
00250 |
Order Callback Phone Number |
|
18 |
60 |
ST |
O |
00251 |
Placer Field 1 |
||
19 |
60 |
ST |
O |
00252 |
Placer Field 2 |
||
20 |
60 |
ST |
O |
00253 |
Filler Field 1 + |
||
21 |
60 |
ST |
O |
00254 |
Filler Field 2 + |
||
22 |
26 |
TS |
C |
00255 |
Results Rpt/Status Chng - Date/Time + |
||
23 |
40 |
CM |
O |
00256 |
Charge to Practice + |
||
24 |
10 |
ID |
O |
0074 |
00257 |
Diagnostic Serv Sect ID |
|
25 |
1 |
ID |
C |
0123 |
00258 |
Result Status + |
|
26 |
400 |
CM |
O |
00259 |
Parent Result + |
||
27 |
200 |
TQ |
O |
Y |
00221 |
Quantity/Timing |
|
28 |
250 |
XCN |
O |
Y/5 |
00260 |
Result Copies To |
|
29 |
200 |
CM |
O |
00261 |
Parent |
||
30 |
20 |
ID |
O |
0124 |
00262 |
Transportation Mode |
|
31 |
250 |
CE |
O |
Y |
00263 |
Reason for Study |
|
32 |
200 |
CM |
O |
00264 |
Principal Result Interpreter + |
||
33 |
200 |
CM |
O |
Y |
00265 |
Assistant Result Interpreter + |
|
34 |
200 |
CM |
O |
Y |
00266 |
Technician + |
|
35 |
200 |
CM |
O |
Y |
00267 |
Transcriptionist + |
|
36 |
26 |
TS |
O |
00268 |
Scheduled Date/Time + |
||
37 |
4 |
NM |
O |
01028 |
Number of Sample Containers * |
||
38 |
250 |
CE |
O |
Y |
01029 |
Transport Logistics of Collected Sample * |
|
39 |
250 |
CE |
O |
Y |
01030 |
Collector's Comment * |
|
40 |
250 |
CE |
O |
01031 |
Transport Arrangement Responsibility |
||
41 |
30 |
ID |
O |
0224 |
01032 |
Transport Arranged |
|
42 |
1 |
ID |
O |
0225 |
01033 |
Escort Required |
|
43 |
250 |
CE |
O |
Y |
01034 |
Planned Patient Transport Comment |
|
44 |
250 |
CE |
O |
0088 |
00393 |
Procedure Code |
|
45 |
250 |
CE |
O |
Y |
0340 |
01316 |
Procedure Code Modifier |
46 |
250 |
CE |
O |
Y |
0411 |
01474 |
Placer Supplemental Service Information |
47 |
250 |
CE |
O |
Y |
0411 |
01475 |
Filler Supplemental Service Information |
Note: The complete description of these fields is provided below as well as in Chapter 4.
The
daggered (+) items in this segment are not created by the placer known to the
filler, not the placer. They are created by the filler and valued as needed
when the OBR segment is returned as part of a report. Hence on a new order
sent to the filler, they are not valued. There is an exception when the filler
initiates the order. In that case, the filler order number is valued and the
placer order number may be blank. They are valued by the filler as needed when
the OBR segment is returned as part of a report.
The starred (*) fields are only relevant when an observation is associated with
a specimen. These are completed by the placer when the placer obtains the
specimen. They are completed by the filler when the filler obtains the
specimen.
OBR-7-observation date/time and OBR-8-observation end date/time
(flagged with #) are the physiologically relevant times. In the case of an
observation on a specimen, they represent the start and end of the specimen
collection. In the case of an observation obtained directly from a subject
(e.g., BP, Chest X-ray), they represent the start and end time of the
observation.
Definition: For the first order transmitted, the sequence number shall be 1; for the second order, it shall be 2; and so on.
Components:
<entity identifier (ST)> ^ <namespace ID (IS)> ^ <universal ID
(ST)> ^ <universal ID type (ID)>
Definition: This field is a case of the Entity Identifier data type (See
2.8.13, "EI - Entity identifier"). The first component is a string that
identifies an individual order (e.g., OBR). A limit of fifteen (15) characters
is suggested but not required. It is assigned by the place (ordering
application). It identifies an order uniquely among all orders from a
particular ordering application. The second through fourth components contain
the application ID of the placing application in the same form as the HD data
type (Section 2.8.18, "HD - Hierarchic designator"). The second component,
namespace ID, is a user-defined coded value that will be uniquely associated
with an application. A limit of six (6) characters is suggested but not
required. A given institution or group of intercommunicating institutions
should establish a unique list of applications that may be potential placers
and fillers and assign unique application IDs. The components are separated by
component delimiters.
There are three situations in which the true placer is somewhat arbitrary (and
thus not unique):
a) in ORC-1-order control value of RO, following an RU replacement;
b) in ORC-1-order control value of CH (child orders); and
c) in ORC-1-order control value of SN (send number).
See the Table Notes under ORC-1-order control for the details of how the
ORC-2-placer order number is assigned in these cases.
A given institution or group of intercommunicating institutions should
establish a list of applications that may be potential placers and fillers of
orders and assign each a unique application ID. The application ID list
becomes one of the institution's master dictionary lists that is documented in
Chapter 8. Since third-party applications (those other than the placer and
filler of an order) can send and receive ORM and ORR messages, the placer
application ID in this field may not be the same as any sending and receiving
application on the network (as identified in the MSH segment).
ORC-2-placer order number is the same as OBR-2-placer order
number. If the placer order number is not present in the ORC, it must be
present in the associated OBR and vice versa. If both fields, ORC-2-placer
order number and OBR-2-placer order number, are valued, they must
contain the same value. When results are transmitted in an ORU message, an ORC
is not required, and the identifying placer order number must be present
in the OBR segments.
These rules apply to the few other fields that are present in both ORC and OBR
for upward compatibility (e.g., quantity/timing, parent numbers, ordering
provider, and ordering call back numbers).
Components:
<entity identifier (ST)> ^ <namespace ID (IS)> ^ <universal ID
(ST)> ^ <universal ID type (ID)>
Definition: This field is the order number associated with the filling
application. It is a case of the Entity Identifier data type (Section 2.8.13,
"EI - Entity Identifier"). Its first component is a string that identifies an
order detail segment (e.g., OBR). A limit of fifteen (15) characters is
suggested but not required. It is assigned by the order filler (receiving)
application. This string must uniquely identify the order (as specified in the
order detail segment) from other orders in a particular filling application
(e.g., clinical laboratory). This uniqueness must persist over time.
The second through fourth components contain the filler application ID, in the
form of the HD data type (see Section 2.8.18, "HD - hierarchic designator").
The second component is a user-defined coded value that uniquely defines the
application from other applications on the network. A limit of six (6)
characters is suggested but not required. The second component of the filler
order number always identifies the actual filler of an order.
A given institution or group of intercommunicating institutions should
establish a list of applications that may be potential placers and fillers of
orders and assign each a unique application ID. The application ID list
becomes one of the institution's master dictionary lists that is documented in
Chapter 8. Since third- party applications (those other than the placer and
filler of an order) can send and receive ORM and ORR messages, the filler
application ID in this field may not be the same as any sending and receiving
application on the network (as identified in the MSH segment).
ORC-3-filler order number is the same as OBR-3-filler order
number. If the filler order number is not present in the ORC, it must be
present in the associated OBR. (This rule is the same for other identical
fields in the ORC and OBR and promotes upward and ASTM compatibility.) This is
particularly important when results are transmitted in an ORU message. In this
case, the ORC is not required and the identifying filler order number must be
present in the OBR segments.
The filler order number (OBR-3 or ORC-3) also uniquely identifies an
order and its associated observations. For example, suppose that an
institution collects observations from several ancillary applications into a
common database and this common database is queried by yet another application
for observations. In this case, the filler order number and placer order
number transmitted by the common database application would be that of the
original filler and placer, respectively, rather than a new one assigned by the
common database application.
Similarly, if a third-party application, not the filler or placer, of an order
were authorized to modify the status of an order (say, cancel it), the
third-party application would send the filler an ORM message containing an ORC
segment with ORC-1-order control equal to "CA" and containing the
original placer order number and filler order number, rather than assign either
itself.
Components:
<identifier (ST)> ^ <text (ST)> ^ <name of coding system
(IS)> ^ <alternate identifier (ST)> ^ <alternate text (ST)> ^
<name of alternate coding system (IS)>
Definition: This field is the identifier code for the requested
observation/test/battery. This can be based on local and/or "universal" codes.
We recommend the "universal" procedure identifier. The structure of this CE
data type is described in the control section.
Definition: This field has been retained for backward compatibility only. It is not used. Previously priority (e.g., STAT, ASAP), but that information is carried as the sixth component of OBR-27-quantity/timing.
Definition: This field has been retained for backward compatibility only. This is not used. Previously requested date/time. That information is now carried in the fourth component of the OBR-27-quantity/timing.
Definition: This field is the clinically relevant date/time of the observation. In the case of observations taken directly from a subject, it is the actual date and time the observation was obtained. In the case of a specimen-associated study, this field shall represent the date and time the specimen was collected or obtained. (This is a results-only field except when the placer or a third party has already drawn the specimen.) This field is conditionally required. When the OBR is transmitted as part of a report message, the field must be filled in. If it is transmitted as part of a request and a sample has been sent along as part of the request, this field must be filled in because this specimen time is the physiologically relevant date-time of the observation.
Definition: This field is the end date and time of a study or timed specimen collection. If an observation takes place over a substantial period of time, it will indicate when the observation period ended. For observations made at a point in time, it will be null. This is a results field except when the placer or a party other than the filler has already drawn the specimen.
Components:
<quantity (NM)> ^ <units (CE)>
Subcomponents of units: <identifier (ST)> & <test (ST)>
& <name of coding system (IS)> & <alternate identifier
(ST)> & <alternate text (ST)> & <name of alternate coding
system (IS)>
Definition: For laboratory tests, the collection volume is the volume of a
specimen. The default unit is ML. Specifically, units should be expressed in
the ISO Standard unit abbreviations (ISO-2955, 1977). This is a results-only
field except when the placer or a party has already drawn the specimen. (See
Chapter 7 for full details about units.)
Components:
In Version 2.3 and later, use instead of the CN data type. <ID number
(ST)> ^ <family name (FN)> ^ <given name (ST)> ^ <second or
further given names or initials thereof (ST)> ^ <suffix (e.g., JR or III)
(ST)> ^ <prefix (e.g., DR) (ST)> ^ <degree (e.g., MD) (IS)> ^
<source table (IS)> ^ <assigning authority (HD)> ^ <name type
code (ID)> ^ <identifier check digit (ST)> ^ <code identifying the
check digit scheme employed (ID)> ^ <identifier type code (IS)> ^
<assigning facility (HD)> ^ <name representation code (ID)> ^
<name context (CE)> ^ <name validity range (DR)> ^ < name
assembly order (ID)>
Subcomponents of assigning authority: <namespace ID (IS)> &
<universal ID (ST)> & <universal ID type (ID)>
Subcomponents of assigning facility ID: <namespace ID (IS)> &
<universal ID (ST)> & <universal ID type (ID)>
Definition: When a specimen is required for the study, this field will
identify the person, department, or facility that collected the specimen.
Either name or ID code, or both, may be present.
Definition:
This field is the action to be taken with respect to the specimens that
accompany or precede this order. The purpose of this field is to further
qualify (when appropriate) the general action indicated by the order control
code contained in the accompanying ORC segment. For example, when a new order
(ORC - "NW") is sent to the lab, this field would be used to tell the lab
whether or not to collect the specimen ("L" or "O"). Refer to HL7 Table
0065 - Specimen action code for valid values.
Value |
Description |
|---|---|
A |
Add ordered tests to the existing specimen |
G |
Generated order; reflex order |
L |
Lab to obtain specimen from patient |
O |
Specimen obtained by service other than Lab |
P |
Pending specimen; Order sent prior to delivery |
R |
Revised order |
S |
Schedule the tests specified below |
Components:
<identifier (ST)> ^ <text (ST)> ^ <name of coding system
(IS)> ^ <alternate identifier (ST)> ^ <alternate text (ST)> ^
<name of alternate coding system (IS)>
Definition: This field is the code and/or text indicating any known or
suspected patient or specimen hazards, e.g., patient with active tuberculosis
or blood from a hepatitis patient. Either code and/or text may be absent.
However, the code is always placed in the first component position and any free
text in the second component. Thus, free text without a code must be preceded
by a component delimiter.
Definition: This field contains any additional clinical information about the patient or specimen. This field is used to report the suspected diagnosis and clinical findings on requests for interpreted diagnostic studies. Examples include reporting the amount of inspired carbon dioxide for blood gasses, the point in the menstrual cycle for cervical pap tests, and other conditions that influence test interpretations. For some orders this information may be sent on a more structured form as a series of OBX segments (see Chapter 7) that immediately follow the order segment.
Definition: For observations requiring a specimen, the specimen received date/time is the actual login time at the diagnostic service. This field must contain a value when the order is accompanied by a specimen, or when the observation required a specimen and the message is a report.
Components:
<specimen source name or code (CE)> ^ <additives (TX)> ^
<freetext (TX)> ^ <body site (CE)> ^ <site modifier (CE)> ^
<collection method modifier code (CE)>
Subcomponents of specimen source name or doe: <identifier (ST)> &
<test (ST)> & <name of coding system (IS)> & <alternate
identifier (ST)> & <alternate text (ST)> & <name of
alternate coding system (ST)>
Subcomponents of body site: <identifier (ST)> & <test (ST)>
& <name of coding system (IS)> & <alternate identifier
(ST)> & <alternate text (ST)> & <name of alternate coding
system (ST)>
Subcomponents of site modifier: <identifier (ST)> & <test
(ST)> & <name of coding system (IS)> & <alternate
identifier (ST)> & <alternate text (ST)> & <name of
alternate coding system (ST)>
Subcomponents of collection method modifier code: <identifier (ST)>
& <test (ST)> & <name of coding system (IS)> &
<alternate identifier (ST)> & <alternate text (ST)> &
<name of alternate coding system (ST)>
Definition: This field identifies the site where the specimen should be
obtained or where the service should be performed.
Veterinary medicine may choose the tables supported for the components of this
field as decided by their industry.
The first component contains the specimen source name or code (as a CE data
type component). (Even in the case of observations whose name implies the
source, a source may be required, e.g., blood culture - heart blood.) Refer
to HL7 table 0070 - Specimen source codes for valid
entries.
The second component should include free text additives to the specimen such as
Heparin, EDTA, or Oxlate, when applicable.
The third is a free text component describing the method of collection when
that information is a part of the order. When the method of collection is
logically an observation result, it should be included as a result segment.
The fourth component specifies the body site from which the specimen was
obtained, and the fifth is the site modifier. For example, the site could be
antecubital fossa, and the site modifier "right." The components of the CE
fields become subcomponents.
Refer to section 7.18.2 for the contents of HL7 Table 0163 - Body
site.
The fifth component indicates whether the specimen is frozen as part of the
collection method. Suggested values are F (Frozen); R (Refrigerated). If the
component is blank, the specimen is assumed to be at room temperature.
Refer to section 7.18.3 for the contents of HL7 Table 0070 - Specimen
source codes.
Components:
In Version 2.3 and later, use instead of the CN data type. <ID number
(ST)> ^ <family name (FN)> ^ <given name (ST)> ^ <second or
further given names or initials thereof (ST)> ^ <suffix (e.g., JR or III)
(ST)> ^ <prefix (e.g., DR) (ST)> ^ <degree (e.g., MD) (IS)> ^
<source table (IS)> ^ <assigning authority (HD)> ^ <name type
code (ID)> ^ <identifier check digit (ST)> ^ <code identifying the
check digit scheme employed (ID)> ^ <identifier type code (IS)> ^
<assigning facility (HD)> ^ <name representation code (ID)> ^
<name context (CE)> ^ <name validity range (DR)> ^ < name
assembly order (ID)>
Subcomponents of assigning authority: <namespace ID (IS)> &
<universal ID (ST)> & <universal ID type (ID)>
Subcomponents of assigning facility ID: <namespace ID (IS)> &
<universal ID (ST)> & <universal ID type (ID)>
Definition: This field identifies the provider who ordered the test. Either
the ID code or the name, or both, may be present. This is the same as
ORC-12-Ordering provider.
Components:
[NNN] [(999)]999-9999 [X99999] [B99999] [C any text] ^
<telecommunication use code (ID)> ^ <telecommunication equipment type
(ID)> ^ <email address (ST)> ^ <country code (NM)> ^
<area/city code (NM)> ^ <phone number (NM)> ^ <extension
(NM)> ^ <any text (ST)>
Definition: This field is the telephone number for reporting a status or a
result using the standard format with extension and/or beeper number when
applicable.
Definition: This field is user field #1. Text sent by the placer will be returned with the results.
Definition: This field is similar to placer field #1.
Definition: This field is definable for any use by the filler (diagnostic service).
Definition: This field is similar to filler field #1.
Definition: This field specifies the date/time results reported or status changed. This field is used to indicate the date and time that the results are composed into a report and released, or that a status, as defined in ORC-5-order status, is entered or changed. (This is a results field only.) When other applications (such as office or clinical database applications) query the laboratory application for un-transmitted results, the information in this field may be used to control processing on the communications link. Usually, the ordering service would want only those results for which the reporting date/time is greater than the date/time the inquiring application last received results.
Components:
<dollar amount (MO)> ^ <charge code (CE)>
Subcomponents of dollar amount: <quantity (NM)> &
<denomination (ID)>
Subcomponents of charge code: <identifier (ST)> & <test
(ST)> & <name of coding system (IS)> & <alternate
identifier (ST)> & <alternate text (ST)> & <name of
alternate coding system (IS)>
Definition: This field is the charge to the ordering entity for the studies
performed when applicable. The first component is a dollar amount when known by
the filler. The second is a charge code when known by the filler (results
only).
Definition:
This field is the section of the diagnostic service where the observation was
performed. If the study was performed by an outside service, the
identification of that service should be recorded here. Refer to HL7
Table 0074 - Diagnostic service section ID for valid entries.
Value |
Description |
|---|---|
AU |
Audiology |
BG |
Blood gases |
BLB |
Blood bank |
CUS |
Cardiac Ultrasound |
CTH |
Cardiac catheterization |
CT |
CAT scan |
CH |
Chemistry |
CP |
Cytopathology |
EC |
Electrocardiac (e.g., EKG, EEC, Holter) |
EN |
Electroneuro (EEG, EMG,EP,PSG) |
HM |
Hematology |
ICU |
Bedside ICU Monitoring |
IMG |
Diagnostic Imaging |
IMM |
Immunology |
LAB |
Laboratory |
MB |
Microbiology |
MCB |
Mycobacteriology |
MYC |
Mycology |
NMS |
Nuclear medicine scan |
NMR |
Nuclear magnetic resonance |
NRS |
Nursing service measures |
OUS |
OB Ultrasound |
OT |
Occupational Therapy |
OTH |
Other |
OSL |
Outside Lab |
PAR |
Parasitology |
PAT |
Pathology (gross & histopath, not surgical) |
PHR |
Pharmacy |
PT |
Physical Therapy |
PHY |
Physician (Hx. Dx, admission note, etc.) |
PF |
Pulmonary function |
RAD |
Radiology |
RX |
Radiograph |
RUS |
Radiology ultrasound |
RC |
Respiratory Care (therapy) |
RT |
Radiation therapy |
SR |
Serology |
SP |
Surgical Pathology |
TX |
Toxicology |
URN |
Urinalysis |
VUS |
Vascular Ultrasound |
VR |
Virology |
XRC |
Cineradiograph |
Definition:
This field is the status of results for this order. This conditional field is
required whenever the OBR is contained in a report message. It is not required
as part of an initial order.
There are two methods of sending status information. If the status is that of
the entire order, use ORC-15-order effective date/time and
ORC-5-order status. If the status pertains to the order detail segment,
use OBR-25-result status and OBR-22-results report/status change -
date/time. If both are present, the OBR values override the ORC values.
This field would typically be used in a response to an order status query where
the level of detail requested does not include the OBX segments. When the
individual status of each result is necessary, OBX-11-observ result
status may be used. Refer to HL7 Table 0123 - Result status
for valid entries.
Value |
Description |
|---|---|
O |
Order received; specimen not yet received |
I |
No results available; specimen received, procedure incomplete |
S |
No results available; procedure scheduled, but not done |
A |
Some, but not all, results available |
P |
Preliminary: A verified early result is available, final results not yet obtained |
C |
Correction to results |
R |
Results stored; not yet verified |
F |
Final results; results stored and verified. Can only be changed with a corrected result. |
X |
No results available; Order canceled. |
Y |
No order on record for this test. (Used only on queries) |
Z |
No record of this patient. (Used only on queries) |
Components:
<OBX-3-observation identifier of parent result (CE)> ^ <OBX-4-sub-ID
of parent result (ST)> ^ <part of OBX-5 observation result from parent
(TX) see discussion>
Subcomponents of OBX-3-observation identifier or parent result:
<identifier (ST)> & <test (ST)> & <name of coding system
(IS)> & <alternate identifier (ST)> & <alternate text
(ST)> & <name of alternate coding system (ST)>
Definition: This field is defined to make it available for other types of
linkages (e.g., toxicology). This important information, together with the
information in OBR-29-parent, uniquely identifies the parent result's
OBX segment related to this order. The value of this OBX segment in the parent
result is the organism or chemical species about which this battery reports.
For example, if the current battery is an antimicrobial susceptibility, the
parent result's identified OBX contains a result which identifies the organism
on which the susceptibility were run. This indirect linkage is preferred
because the name of the organism in the parent result may undergo several
preliminary values prior to finalization.
The third component may be used to record the name of the microorganism
identified by the parent result directly. The organism in this case should be
identified exactly as it is in the parent culture.
We emphasize that this field does not take the entire result field from the
parent. It is meant only for the text name of the organism or chemical
subspecies identified. This field is included only to provide a method for
linking back to the parent result for those systems which could not generate
unambiguous Observation IDs and sub-IDs.
This field is present only when the parent result is identified by
OBR-29-parent and the parent spawn child orders for each of many
results. (See Chapter 7 for more details about this linkage.)
A second mode of conveying this information is to use a standard observation
result segment (OBX). If more than one organism is present,
OBX-4-observation subID is used to distinguish them. In this case, the
first OBX with subID N will contain a value identifying the Nth microorganism,
and each additional OBX with subID N will contain susceptibility values for a
given antimicrobial test on this organism.
 See Section 4.2, "Quantity/Timing (TQ)
Definition."
ORC-7-quantity/timing is the same as OBR-27-quantity/timing. If
the ORC-7 and OBR-27 are both valued, then both should be valued exactly the
same. If the quantity/timing is not present in the ORC, it must be present in
the associated OBR. (This rule is the same for other identical fields in the
ORC and OBR and promotes upward and ASTM compatibility.) This is particularly
important when results are transmitted in an ORU message. In this case, the
ORC is not required and the identifying filler order number must be present in
the OBR segments.
For example, if an OBR segment describes a unit of blood, this field might
request that three (3) such units be given on successive mornings. In this
case ORC-7-quantity/timing would be "1^XQAM^X3".
ORC-7-quantity/timing is the same as OBR-27-quantity/timing.
To send information about "collection time", use the `text' component of the TQ
data type in either the ORC-7 or OBR-27. Use the Note segment (NTE) to send
`special instructions' information for a test/service (e.g., draw specimen from
left arm).
Components:
In Version 2.3 and later, use instead of the CN data type. <ID number
(ST)> ^ <family name (FN)> ^ <given name (ST)> ^ <second or
further given names or initials thereof (ST)> ^ <suffix (e.g., JR or III)
(ST)> ^ <prefix (e.g., DR) (ST)> ^ <degree (e.g., MD) (IS)> ^
<source table (IS)> ^ <assigning authority (HD)> ^ <name type
code (ID)> ^ <identifier check digit (ST)> ^ <code identifying the
check digit scheme employed (ID)> ^ <identifier type code (IS)> ^
<assigning facility (HD)> ^ <name representation code (ID)> ^
<name context (CE)> ^ <name validity range (DR)> ^ < name
assembly order (ID)>
Subcomponents of assigning authority: <namespace ID (IS)> &
<universal ID (ST)> & <universal ID type (ID)>
Subcomponents of assigning facility ID: <namespace ID (IS)> &
<universal ID (ST)> & <universal ID type (ID)>
Definition: This field is the people who are to receive copies of the results.
By local convention, either the ID number or the name may be absent.
Components:
<parent's placer order number (EI)> ^ <parent's filler order number
(EI)>
Subcomponents of parent's placer order number: <entity identifier
(ST)> & <namespace ID (IS)> & <universal ID (ST)> &
<universal ID type (IS)>
Subcomponents of parent's filler order number: <entity identifier
(ST)> & < <namespace ID (IS)> & <universal ID (ST)>
& <universal ID type (IS)>
Definition: This field is identical to ORC-8-parent. This field
relates a child to its parent when a parent/child relationship exists. For
example, observations that are spawned by previous observations, e.g.,
antimicrobial susceptibilities spawned by blood cultures, need to record the
parent (blood culture) filler order number here. The parent/child mechanism is
described under the order control field notes (see Segment ORC field notes in
Section <IP_ADDRESS>.1, "Table notes for order control codes of ORC." It is
required when the order is a child.
Parent is a two-component field. The first component contains the parent's
placer order number. The second component is optional and contains the
parent's filler order number. The components of the placer order number and
the filler order number are transmitted in subcomponents of the two components
of this field.
Definition:
This field identifies how (or whether) to transport a patient, when
applicable. Refer to HL7 Table 0124 - Transportation mode for
valid codes.
Value |
Description |
|---|---|
CART |
Cart - patient travels on cart or gurney |
PORT |
The examining device goes to patient's location |
WALK |
Patient walks to diagnostic service |
WHLC |
Wheelchair |
Components:
<identifier (ST)> ^ <text (ST)> ^ <name of coding system
(IS)> ^ <alternate identifier (ST)> ^ <alternate text (ST)> ^
<name of alternate coding system (IS)>
Definition: This field is the code or text using the conventions for coded
fields given in Chapter 2, Control. This is required for some studies to
obtain proper reimbursement.
Components:
<name (CN)> ^ <start date/time (TS)> ^ <end date/time (TS)> ^
<point of care (IS)> ^ <room (IS)> ^ <bed (IS)> ^
<facility (HD)> ^ <location status (IS)> ^ <patient location
type (IS)> ^ <building (IS)> ^ <floor (IS)>
Subcomponents of name: <ID number (ST)> & <family name
(ST)> & <given name (ST)> & <middle initial or name
(ST)> & <suffix (e.g., JR. III) (ST)> & <prefix (e.g.,
DR)> & <degree (e.g., MD) (ST)> & <source table (IS)>
& <assigning authority (HD)>
Subcomponents of facility: <namespace ID (IS)> & <universal
ID (ST)> & <universal ID type (ID)>
Definition: This field identifies the physician or other clinician who
interpreted the observation and is responsible for the report content.
Components:
<name (CN)> ^ <start date/time (TS)> ^ <end date/time (TS)> ^
<point of care (IS)> ^ <room (IS)> ^ <bed (IS)> ^
<facility (HD)> ^ <location status (IS)> ^ <patient location
type (IS)> ^ <building (IS)> ^ <floor (IS)>
Subcomponents of name: <ID number (ST)> & <family name
(ST)> & <given name (ST)> & <middle initial or name
(ST)> & <suffix (e.g., JR. III) (ST)> & <prefix (e.g.,
DR)> & <degree (e.g., MD) (ST)> & <source table (IS)>
& <assigning authority (HD)>
Subcomponents of facility: <namespace ID (IS)> & <universal
ID (ST)> & <universal ID type (ID)>
Definition: This field identifies the clinical observer who assisted with the
interpretation of this study.
Components:
<name (CN)> ^ <start date/time (TS)> ^ <end date/time (TS)> ^
<point of care (IS)> ^ <room (IS)> ^ <bed (IS)> ^
<facility (HD)> ^ <location status (IS)> ^ <patient location
type (IS)> ^ <building (IS)> ^ <floor (IS)>
Subcomponents of name: <ID number (ST)> & <family name
(ST)> & <given name (ST)> & <middle initial or name
(ST)> & <suffix (e.g., JR. III) (ST)> & <prefix (e.g.,
DR)> & <degree (e.g., MD) (ST)> & <source table (IS)>
& <assigning authority (HD)>
Subcomponents of facility: <namespace ID (IS)> & <universal
ID (ST)> & <universal ID type (ID)>
Definition: This field identifies the performing technician.
Components:
<name (CN)> ^ <start date/time (TS)> ^ <end date/time (TS)> ^
<point of care (IS)> ^ <room (IS)> ^ <bed (IS)> ^
<facility (HD)> ^ <location status (IS)> ^ <patient location
type (IS)> ^ <building (IS)> ^ <floor (IS)>
Subcomponents of name: <ID number (ST)> & <family name
(ST)> & <given name (ST)> & <middle initial or name
(ST)> & <suffix (e.g., JR. III) (ST)> & <prefix (e.g.,
DR)> & <degree (e.g., MD) (ST)> & <source table (IS)>
& <assigning authority (HD)>
Subcomponents of facility: <namespace ID (IS)> & <universal
ID (ST)> & <universal ID type (ID)>
Definition: This field identifies the report transcriber.
Definition: This field is the date/time the filler scheduled an observation, when applicable (e.g., action code in OBR-11-specimen action code = "S"). This is a result of a request to schedule a particular test and provides a way to inform the Placer of the date/time a study is scheduled (result only).
Definition: This field identifies the number of containers for a given sample. For sample receipt verification purposes; may be different from the total number of samples which accompany the order.
Components:
<identifier (ST)> ^ <text (ST)> ^ <name of coding system
(IS)> ^ <alternate identifier (ST)> ^ <alternate text (ST)> ^
<name of alternate coding system (IS)>
Definition: This field is the means by which a sample reaches the diagnostic
service provider. This information is to aid the lab in scheduling or
interpretation of results. Possible answers: routine transport van, public
postal service, etc. If coded, requires a user-defined table.
Components:
<identifier (ST)> ^ <text (ST)> ^ <name of coding system
(IS)> ^ <alternate identifier (ST)> ^ <alternate text (ST)> ^
<name of alternate coding system (IS)>
Definition: This field is for reporting additional comments related to the
sample. If coded, requires a user-defined table. If only free text is reported,
it is placed in the second component with a null in the first component, e.g.,
^difficult clotting after venipuncture and ecchymosis.
Components:
<identifier (ST)> ^ <text (ST)> ^ <name of coding system
(IS)> ^ <alternate identifier (ST)> ^ <alternate text (ST)> ^
<name of alternate coding system (IS)>
Definition: This field is an indicator of who is responsible for arranging
transport to the planned diagnostic service. Examples: Requester, Provider,
Patient. If coded, requires a user-defined table.
Definition:
This field is an indicator of whether transport arrangements are known to have
been made. Refer to HL7 Table 0224 - Transport arranged
for valid codes.
Value |
Description |
|---|---|
A |
Arranged |
N |
Not Arranged |
U |
Unknown |
Definition:
This field is an indicator that the patient needs to be escorted to the
diagnostic service department. Note: The nature of the escort requirements
should be stated in the OBR-43-planned patient transport comment
field. See HL7 Table 0225 - Escort required for valid values.
Value |
Description |
|---|---|
R |
Required |
N |
Not Required |
U |
Unknown |
Components:
<identifier (ST)> ^ <text (ST)> ^ <name of coding system
(IS)> ^ <alternate identifier (ST)> ^ <alternate text (ST)> ^
<name of alternate coding system (IS)>
Definition: This field is the code or free text comments on special
requirements for the transport of the patient to the diagnostic service
department. If coded, requires a user-defined table.
Components:
<identifier (ST)> ^ <text (ST)> ^ <name of coding system
(IS)> ^ <alternate identifier (ST)> ^ <alternate text (ST)> ^
<name of alternate coding system (IS)>
Definition: This field contains a unique identifier assigned to the procedure,
if any, associated with the Universal Service ID reported in field 4.
User-defined Table 0088 - Procedure code is used as the HL7 identifier
for the user-defined table of values for this field. This field is a CE data
type for compatibility with clinical and ancillary systems. This field will
usually contain the HCPCS code associated with the order.
Components:
<identifier (ST)> ^ <text (ST)> ^ <name of coding system
(IS)> ^ <alternate identifier (ST)> ^ <alternate text (ST)> ^
<name of alternate coding system (IS)>
Definition: This field contains the procedure code modifier to the procedure
code reported in field 44, when applicable. Procedure code modifiers are
defined by regulatory agencies such as HCFA and the AMA. Multiple modifiers
may be reported. User-defined Table 0088 - Procedure code is used as the
HL7 identifier for the user-defined table of values for this field.
Components:
<identifier (ST)> ^ <text (ST)> ^ <name of coding system
(IS)> ^ <alternate identifier (ST)> ^ <alternate text (ST)> ^
<name of alternate coding system (IS)>
Definition: This field contains supplemental service information sent from the
placer system to the filler system for the universal procedure code reported in
OBR-4 Universal Service ID. This field will be used to provide ordering
information detail that is not available in other, specific fields in the OBR
segment. Multiple supplemental service information elements may be reported.
Refer to User-defined table 0411 - Supplemental service information
values for suggested values.
This field can be used to describe details such as whether study is to be done
on the right or left, for example where the study is of the arm and the order
master file does not distinguish right from left or whether the study is to be
done with or without contrast (when the order master file does not make such
distinctions).
Components:
<identifier (ST)> ^ <text (ST)> ^ <name of coding system
(IS)> ^ <alternate identifier (ST)> ^ <alternate text (ST)> ^
<name of alternate coding system (IS)>
Definition: This field contains supplemental service information sent from the
filler system to the placer system for the procedure code reported in OBR-4
Universal Service ID. This field will be used to report ordering
information details that is not available in other, specific fields in the OBR
segment. Typically it will reflect the same information as was sent to the
filler system in OBR-46-Placer supplemental information unless the
order was modified in which case the filler system will report what was
actually performed using this field. Multiple supplemental service information
elements may be reported. Refer to User-defined Table 0411 -
Supplemental service information values for suggested values.
This field can be used to describe details such as whether study is to be done
on the right or left, for example where the study is of the arm and the order
master file does not distinguish right from left or whether the study is to be
done with or without contrast (when the order master file does not make such
distinctions).
Value |
Description |
|---|---|
1ST |
First |
2ND |
Second |
3RD |
Third |
4TH |
Fourth |
5TH |
Fifth |
ANT |
Anterior |
A/P |
Anterior/Posterior |
BLT |
Bilateral |
DEC |
Decubitus |
DST |
Distal |
LAT |
Lateral |
LFT |
Left |
LLQ |
Left Lower Quadrant |
LOW |
Lower |
LUQ |
Left Upper Quadrant |
MED |
Medial |
OR |
Operating Room |
PED |
Pediatric |
POS |
Posterior |
PRT |
Portable |
PRX |
Proximal |
REC |
Recumbent |
RLQ |
Right Lower Quadrant |
RGH |
Right |
RUQ |
Right Upper Quadrant |
UPP |
Upper |
UPR |
Upright |
WCT |
With Contrast |
WOC |
Without Contrast |
WSD |
With Sedation |
Individual implementations may extend this table using other appropriate vocabularies.
The
OBX segment is used to transmit a single observation or observation fragment.
It represents the smallest indivisible unit of a report. Its structure is
summarized in Figure 7-5.
Its principal mission is to carry information about observations in report
messages. But the OBX can also be part of an observation order (see Section
4.2, "Order Message Definitions"). In this case, the OBX carries clinical
information needed by the filler to interpret the observation the filler makes.
For example, an OBX is needed to report the inspired oxygen on an order for a
blood oxygen to a blood gas lab, or to report the menstrual phase information
which should be included on an order for a pap smear to a cytology lab.
Appendix 7A includes codes for identifying many of pieces of information needed
by observation producing services to properly interpret a test result. OBX is
also found in other HL7 messages that need to include patient clinical
information.
SEQ |
LEN |
DT |
OPT |
RP/# |
TBL# |
ITEM# |
ELEMENT NAME |
|---|---|---|---|---|---|---|---|
1 |
4 |
SI |
O |
00569 |
Set ID - OBX |
||
2 |
2 |
ID |
C |
0125 |
00570 |
Value Type |
|
3 |
250 |
CE |
R |
00571 |
Observation Identifier |
||
4 |
20 |
ST |
C |
00572 |
Observation Sub-ID |
||
5 |
65536[1] |
|
* |
C |
Y[2] |
00573 |
Observation Value |
||||||
6 |
250 |
CE |
O |
00574 |
Units |
||
7 |
60 |
ST |
O |
00575 |
References Range |
||
8 |
5 |
IS |
O |
Y/5 |
0078 |
00576 |
Abnormal Flags |
9 |
5 |
NM |
O |
00577 |
Probability |
||
10 |
2 |
ID |
O |
Y |
0080 |
00578 |
Nature of Abnormal Test |
11 |
1 |
ID |
R |
0085 |
00579 |
Observation Result Status |
|
12 |
26 |
TS |
O |
00580 |
Date Last Observation Normal Value |
||
13 |
20 |
ST |
O |
00581 |
User Defined Access Checks |
||
14 |
26 |
TS |
O |
00582 |
Date/Time of the Observation |
||
15 |
250 |
CE |
O |
00583 |
Producer's ID |
||
16 |
250 |
XCN |
O |
Y |
00584 |
Responsible Observer |
|
17 |
250 |
CE |
O |
Y |
00936 |
Observation Method |
|
18 |
22 |
EI |
O |
Y |
01479 |
Equipment Instance Identifier |
|
19 |
26 |
TS |
O |
01480 |
Date/Time of the Analysis |
Definition: This field contains the sequence number. For compatibility with ASTM.
Definition:
This field contains the format of the observation value in OBX. It must be
valued if OBX-11-Observ result status is not valued with an `X". If the
value is CE then the result must be a coded entry. When the value type is TX
or FT then the results are bulk text. The valid values for the value type of
an observation are listed in HL7 Table 0125 - Value type.
The observation value must be represented according to the format for the data
type defined in Chapter 2, Section 2.9, "Data Types." For example, a PN
consists of 6 components, separated by component delimiters.
Although NM is a valid type, observations which are usually reported as numbers
will sometimes have the string (ST) data type because non-numeric characters
are often reported as part of the result, e.g., >300 to indicate the result
was off-scale for the instrument. In the example, ">300", ">" is a
symbol and the digits are considered a numeric value. However, this usage of
the ST type should be discouraged since the SN (structured numeric) data type
now accommodates such reporting and, in addition, permits the receiving system
to interpret the magnitude.
All HL7 data types are valid, and are included in Table 0125 except CM, CQ, SI,
and ID. For a CM definition to have meaning, the specifics about the CM must
be included in the field definition. OBX-5-observation value is a
general field definition that is influenced by the data type OBX-3, so
CMs are undefined in this context. CQ is invalid because units for
OBX-5-observation value are always specified explicitly in an OBX
segment with OBX-6 units. SI is invalid because it only applied to HL7
message segments, and ID because it requires a constant field definition.
The RP value (reference pointer) must be used if the actual observation value
is not sent in OBX but exists somewhere else. For example, if the observation
consists of an image (document or medical), the image itself cannot be sent in
OBX. The sending system may in that case opt to send a reference pointer. The
receiving system can use this reference pointer whenever it needs access to the
actual image through other interface standards, e.g., DICOM, or through
appropriate data base servers.
Value |
Description |
|---|---|
AD |
Address |
CE |
Coded Entry |
CF |
Coded Element With Formatted Values |
CK |
Composite ID With Check Digit |
CN |
Composite ID And Name |
CP |
Composite Price |
CX |
Extended Composite ID With Check Digit |
DT |
Date |
ED |
Encapsulated Data |
FT |
Formatted Text (Display) |
MO |
Money |
NM |
Numeric |
PN |
Person Name |
RP |
Reference Pointer |
SN |
Structured Numeric |
ST |
String Data. |
TM |
Time |
TN |
Telephone Number |
TS |
Time Stamp (Date & Time) |
TX |
Text Data (Display) |
XAD |
Extended Address |
XCN |
Extended Composite Name And Number For Persons |
XON |
Extended Composite Name And Number For Organizations |
XPN |
Extended Person Name |
XTN |
Extended Telecommunications Number |
The
full definition of these data types is given in Chapter 2, Section 2.9, "Data
Types." The structured numeric (SN) data type, new to version 2.3, provides
for reporting ranges (e.g., 3-5 or 10-20), titres (e.g., 1:10), and
out-of-range indicators (e.g., >50) in a structured and computer
interpretable way.
We allow the FT data type in the OBX segment but its use is discouraged.
Formatted text usually implies a meaningful structure e.g., a list of three
independent diagnoses reported on different lines. But ideally, the structure
in three independent diagnostic statements would be reported as three separate
OBX segments.
TX should not be used except to send large amounts of text. In the TX
data type, the repeat delimiter can only be used to identify paragraph breaks.
Use ST to send short, and possibly encodable, text strings.
Components:
<identifier (ST)> ^ <text (ST)> ^ <name of coding system
(IS)> ^ <alternate identifier (ST)> ^ <alternate text (ST)> ^
<name of alternate coding system (IS)>
Definition: This field contains a unique identifier for the observation. The
format is that of the Coded Element (CE). Example: 8625-6^P-R interval^LN.
In most systems the identifier will point to a master observation table
that will provide other attributes of the observation that may be used by the
receiving system to process the observations it receives. A set of message
segments for transmitting such master observation tables is described in
Chapter 8. The relation of an observation ID to a master observation table is
analogous to the relationship between a charge code (in a billing record) and
the charge master.
When local codes are used as the first identifier in this field we strongly
encourage sending a universal identifier as well to permit receivers to
equivalence results from different providers of the same service (e.g., a
hospital lab and commercial lab that provides serum potassium to a nursing
home). LOINC® is an HL7 approved code system for the Observation
identifier. It covers observations and measurements, such as laboratory tests,
physical findings, radiology studies, and claims attachments and can be
obtained from www.regenstrief.org/loinc/loinc.ht
m.
One possible universal identifier is LOINC® codes for laboratory
and clinical measurements (see User-defined Table 0396 and the HL7
www list server) and Appendix X2 of ASTM E1467 for neurophysiology tests.
Definition:
This field is used to distinguish between multiple OBX segments with the same
observation ID organized under one OBR. For example, a chest X-ray report
might include three separate diagnostic impressions. The standard requires
three OBX segments, one for each impression. By putting a 1 in the Sub-ID of
the first of these OBX segments, 2 in the second, and 3 in the third, we can
uniquely identify each OBX segment for editing or replacement.
The sub-identifier is also used to group related components in reports such as
surgical pathology. It is traditional for surgical pathology reports to
include all the tissues taken from one surgical procedure in one report.
Consider, for example, a single surgical pathology report that describes the
examination of gallbladder and appendix tissue. This report would be
transmitted roughly as shown in Figure 7-2.
Distinct Observations |
88304&ANT |
88304&GDT |
80304&MDT |
80304&IMP |
Sub ID 1st Group |
1 |
1 |
1 |
1 |
Sub ID 2nd Group |
2 |
2 |
2 |
2 |
The
use of Sub IDs to group results is equivalent to defining a table, and the use
of sub IDs to distinguish repeats is just a special case, represented by one
column in this table.
However, this approach introduces ambiguities if we have a set of repeating
observations within a group, e.g., if the appendix observations include two
impressions as in the 8th and 9th OBXs shown in Figure 7-7. This really
represents the existence of a row nested within a single cell of the table
given above.
Definition:
This field contains the value observed by the observation producer.
OBX-2-value type contains the data type for this field according to
which observation value is formatted. It is not a required field because some
systems will report only the normalcy/abnormalcy (OBX-8), especially in
product experience reporting.
Representation
This field contains the value of OBX-3-observation identifier of the
same segment. Depending upon the observation, the data type may be a number
(e.g., a respiratory rate), a coded answer (e.g., a pathology impression
recorded as SNOMED), or a date/time (the date/time that a unit of blood is sent
to the ward). An observation value is always represented as the data type
specified in OBX-2-value type of the same segment. Whether numeric or
short text, the answer shall be recorded in ASCII text.
Reporting logically independent observations
The main sections of dictated reports, such as radiologic studies or history
and physicals, are reported as separate OBX segments. In addition, each
logically independent observation should be reported in a separate OBX segment,
i.e. one OBX segment should not contain the result of more than one
logically independent observation. This requirement is included to assure that
the contents of OBX-6-units, OBX-8-abnormal flags, and
OBX-9-probability can be interpreted unambiguously. The electrolytes
and vital signs batteries, for example, would each be reported as four separate
OBX segments. Two diagnostic impressions, e.g., congestive heart failure and
pneumonia, would also be reported as two separate OBX segments whether reported
as part of a discharge summary or chest X-ray report. Similarly, two bacterial
organisms isolated in a single bacterial culture would be reported as two
separate OBX segments.
Though two independent diagnostic statements cannot be reported in one
OBX segment, multiple categorical responses are allowed (usually as CE data
types separated by repeat delimiters), so long as they are fragments
(modifiers) that together construct one diagnostic statement. Right upper lobe
(recorded as one code) and pneumonia (recorded as another code), for example,
could be both reported in one OBX segment. Such multiple "values" would be
separated by repeat delimiters.
Multiple OBX segments with the same observation ID and Sub ID
In some systems, a single observation may include fragments of more than
one data type. The most common example is a numeric result followed by coded
comments (CE). In this case, the logical observation can be sent in more than
one OBX segment. For example, one segment of numeric or string data type for
the numeric result and another segment of CE data type for coded comments. If
the producer was reporting multiple coded comments they would all be sent in
one OBX segment separated by repeat delimiters because they all modified a
single logical observation. Multiple OBX segments with the same observation ID
and sub ID should always be sent in sequence with the most significant OBX
segment (the one that has the normal flag/units and or reference range and
status flag) first. The value of OBX-6 through 12 should be null in any
following OBX segments with the same OBX-3-observation identifier and
OBX-4-observation sub-ID. For the purpose of replacement or deletion,
multiple OBX segments with the same observation ID and sub ID are treated as a
unit. If any are replaced or deleted, they all are replaced.
Coded values
When an OBX segment contains values of CE data types, the observations are
stored as a combination of codes and/or text. In Section 7.5.3, "CSS -
clinical study data schedule segment," examples of results that are represented
as CE data types are shown in the first and second OBX segments of OBR 1 and
the first and second OBX segments of OBR 2. The observation may be an
observation battery ID (for recommended studies), a diagnostic code or finding
(for a diagnostic impression), or an anatomic site for a pathology report, or
any of the other kinds of coded results.
It is not necessary to always encode the information stored within a coded
observation. For example, a chest X-ray impression could be transmitted as
pure text even though it has a CE data type. In this case, the test must be
recorded as the second component of the result code, e.g.,
OBX|1|CE|71020&IMP|1|^CONGESTIVE HEART FAILURE.|...<cr>
However, separate impressions, recommendations, etc., even if recorded as pure
text, should be recorded in separate result segments. That is, congestive
heart failure and pneumonia should not be sent as:
OBX|1|CE|71020&IMP|1|^CONGESTIVE HEART FAILURE AND
PNEUMONIA|...<cr>
but as:
OBX|1|CE|71020&IMP|1|^CONGESTIVE HEART FAILURE|...<cr>
OBX|2|CE|71020&IMP|2|^PNEUMONIA|....<cr>
Even better would be fully-coded results that include computer understandable
codes (component 1) instead of, or in addition to, the text description
(component 2). One may include multiple values in a CE value and these can be
mixtures of code and text, but only when they are needed to construct one
diagnosis, impression, or concept. When text follows codes as an independent
value it would be taken as a modifier or addenda to the codes. E.g.,
OBX|1|CE|710120&IMP^CXR|1|428.0^CONGESTIVE HEART FAILURE^I9C~^MASSIVE
HEART|...<cr>
The text in component 2 should be an accurate description of the code in
component 1. Likewise, if used, the text in component 5 should be an accurate
description of the code in component 4.
Components:
<identifier (ST)> ^ <text (ST)> ^ <name of coding system
(IS)> ^ <alternate identifier (ST)> ^ <alternate text (ST)> ^
<name of alternate coding system (IS)>
Background: When an observation's value is measured on a continuous scale, one
must report the measurement units within the units field of the OBX segment.
Since HL7 Version 2.2 of the specification, all fields that contain units are
of data type CE. The default coding system for the units codes consists of the
ISO abbreviation for a single case unit (ISO 2955-83) plus extensions that do
not collide with ISO abbreviations. We designate this coding system as ISO+
(see Figure 7-13). Both the ISO unit's abbreviations and the extensions are
defined in Section <IP_ADDRESS>.2, "ISO and ANSI customary units abbreviations."
The ISO+ abbreviations are the codes for the default coding system.
Consequently, when ISO+ units are being used, only ISO+ abbreviations need be
sent, and the contents of the units field will be backward compatible to HL7
Version 2.1.
We
strongly encourage observation producers to use ISO+ abbreviated units
exclusively, but permit the use of other code systems, including US customary
units (ANSI X3.50) and locally defined codes where necessary. Local units are
designated L or 99zzz where z is an alphanumeric character (see Figures
7-2 and 73). ANSI X3.50 - 1986 provides an excellent description of these
standards, as well as a table of single case abbreviations for US customary
units such as foot or gallon.
We had originally intended to include the ANSI X3.50 - 1986 US customary units
in the default ISO+ coding system. However, there are overlaps between ISO's
abbreviations and the abbreviations for US customary units. For example,
ft is the abbreviation for foot in US customary units and for femtotesla
in ISO; pt is the abbreviation for pint in US customary and for
picotesla in ISO. (Be aware that the ANSI document also differs from the ISO
document regarding the abbreviation of a few ISO units, as well.) In order to
avoid potential ambiguity, we have defined another coding system, designated
ANS+. It includes the US customary units (e.g., feet, pounds) and ISO
abbreviations defined in ANSI X3.50 - 1986, as well as other non-metric units
listed in Figure 7-13 and the ISO combinations of these units. Be aware that a
few of the ANSI ISO unit abbreviations differ from their abbreviations
in ISO (see note at bottom of Figure 7-13).
Because the ANS+ specification includes both ISO and US customary units,
as well as miscellaneous non-metric units, some of the abbreviations are
ambiguous. Although there should be little confusion, in the context of a
particular observation, this ambiguity is a good reason for avoiding ANS+ unit
codes when possible.
When ANS+ units codes (abbreviations) are being transmitted, ANS+ must
be included in the third (sixth) component of the field. If the units of
distance were transmitted as meters (ISO+) it would be transmitted as m
because ISO+ is the default coding system for units. However, if transmitted
in the US customary units of feet, the units would be transmitted as
ft^^ANS+. When required, the full text of the units can be sent as the
second component in keeping with the CE data type conventions.
Both ISO and ANSI also provide a set of mixed case abbreviations, but these
abbreviations cannot be translated to single case without loss of meaning, and
should not be used in this specification whose content is required to be case
insensitive.
ISO
builds its units from seven base dimensions measured as meters, kilograms,
seconds, amperes, kelvins, moles and candelas (see Figure 7-6). Other units
can be derived from these by adding a prefix to change the scale and/or by
creating an algebraic combination of two or more base or derived units.
However, some derived units have acquired their own abbreviations (see Figure
7-6). Abbreviations for U.S. customary units are given in Figure 7-6.
The ISO rules, well explained in ANSI X3.50, provide a way to create units of
different scales by adding multiplier prefixes. These prefixes can be
expressed as words or abbreviations. In this Standard we are only
concerned with the abbreviations.
Units |
Abbreviation |
Units |
Abbreviation |
Units |
Abbreviation |
Base units code/abbreviations |
|||||
ampere |
a |
kelvin |
k |
meter |
m |
candela |
cd |
Kilogram |
kg |
mole |
mol |
second |
s |
||||
Derived units with specified name and abbreviation |
|||||
coulomb |
c |
hour |
Hr |
pascal |
pal |
day |
d |
joule |
J |
volt |
v |
degree Celsius |
cel |
minute (ti) |
Min |
watt |
w |
farad |
f |
newton |
N |
weber |
wb |
hertz |
hz |
ohm |
Ohm |
year |
ann |
Other units |
|||||
atomic mass unit |
u |
grey |
gy |
minute of arc |
mnt |
Bel |
b |
henry |
h |
radian |
rad |
Decibel |
db |
liter |
l |
siemens |
sie |
Degree |
deg |
lumen |
Lm |
steradian |
sr |
Gram |
g |
lux |
Lx |
tesla |
t |
See ISO 2955-1983 for full set |
The
ISO abbreviations for multiplier prefixes are given in Figure 7-12. Prefixes
ranging from 10-24 (1/billion billionth) to 1024 (a
billion billion) are available. The single case abbreviation for kilo (x1000)
is k. A unit consisting of 1000 seconds would be abbreviated as
ks, 1000 grams as kg, 1000 meters as km, and so on. Some
prefixes share the abbreviation of a base unit. Farad and femto, for example,
(10-18) both have the abbreviation of f. To avoid confusion,
ISO forbids the use of solitary prefixes. It also deprecates the use of two
prefixes in one complex unit. Thus, f always means farad, ff
would mean 1 million billionth of a farad. Compound prefixes are not
allowed.
A unit can be raised to an exponential power. Positive exponents are
represented by a number immediately following a unit's abbreviation, i.e., a
square meter would be denoted by m2. Negative exponents are signified by a
negative number following the base unit, e.g., 1/m2 would be
represented as m-2. Fractional exponents are expressed by a numeric
fraction in parentheses: the square root of a meter would be expressed as
m(1/2). The multiplication of units is signified by a period (.) between the
units, e.g., meters X seconds would be denoted m.s. Notice that spaces
are not permitted. Division is signified by a slash (/) between two units,
e.g. meters per second would be denoted as m/s. Algebraic combinations
of ISO unit abbreviations constructed by dividing, multiplying, or
exponentiating base ISO units, are also valid ISO abbreviations units.
Exponentiation has precedence over multiplication or division. For example,
microvolts squared per hertz (a unit of spectral power) would be denoted
uv2/hz and evaluated as uv 2/hz while microvolts
per square root of hertz (a unit of spectral amplitude) would be denoted
uv/hz(1/2) and evaluated as uv/hz½. If more than one division
operator is included in the expression the associations should be parenthesized
to avoid any ambiguity, but the best approach is to convert a/(b/c) to a.c/b or
a.c.b-1 to simplify the expression.
The ISO code is a grammar for building units. The rules for building these
units are found in Figures 7-6 and 7-8. Figure 7-7 should be used only with
English units and should not be used in conjunction with Figure 7-8. The ISO+
table (Figure 7-13) includes the most common such units constructed from this
grammar (as well as important non-ISO units). Other ISO units derived from the
grammar are valid as well.
Units |
Abbreviation |
Units |
Abbreviation |
Units |
Abbreviation |
LENGTH |
VOLUME |
TIME |
|||
inch |
in |
cubic foot |
cft |
year |
yr |
foot |
ft |
cubic inch |
cin |
month |
mo |
mile (statute) |
mi |
cubic yard |
cyd |
week |
wk |
nautical mile |
nmi |
tablespoon |
tbs |
day |
d |
rod |
rod |
teaspoon |
tsp |
hour |
hr |
yard |
yd |
pint |
pt |
minute |
min |
quart |
qt |
second |
sec |
||
gallon |
gal |
||||
ounce (fluid) |
foz |
||||
AREA |
MASS |
||||
square foot |
sqf |
dram |
dr |
||
square inch |
sin |
grain |
gr (avoir) |
||
square yard |
syd |
ounce (weight) |
oz |
||
pound |
lb |
||||
Other ANSI units, derived units, and miscellaneous |
|||||
**British thermal unit |
btu |
**degrees Fahrenheit |
degf |
**millirad |
mrad |
cubic feet/minute |
cft/min |
**feet/minute |
ft/min |
**RAD |
rad |
Note: The abbreviations for conventional U.S. units of time are the same as ISO, except for year. ISO = ANN, AMSI = yr. The metric units in X3.50 are the same as ISO, except for: pascal ("pa" in ANSI, "pal" in ISO); ANSI uses "min" for both time and arc while ISO uses "mnt" for minutes of arc; and in ISA seconds are abbreviated "s", in ANSI, "sec". |
|||||
This list is not exhaustive. Refer to ANSI X3.50-1986, Table 1, for other metric and standard U.S. units. |
|||||
**Non-metric units not explicitly listed in ANSI |
Prefix |
Code |
Prefix |
Code |
||
|---|---|---|---|---|---|
yotta* |
1024 |
ya |
yocto |
10-24 |
y |
zetta* |
1021 |
za |
zepto |
10-21 |
z |
exa |
1018 |
ex |
atto |
10-18 |
a |
peta |
1015 |
pe |
femto |
10-15 |
f |
tera |
1012 |
t |
pico |
10-12 |
p |
giga |
109 |
g |
nano |
10-9 |
n |
mega |
106 |
ma |
micro |
10-6 |
u |
kilo |
103 |
k |
milli |
10-3 |
m |
hecto |
102 |
h |
centi |
10-2 |
c |
deca |
101 |
da |
deci |
10-1 |
d |
*These abbreviations are not defined in the ISO specification for single case abbreviations. |
Figure
7-9 lists the abbreviations for common ISO derived units. It also includes
standard unit abbreviations for common units, e.g., Milliequivalents, and
international units, mm(Hg), and for counting per which we denote by a division
sign, a denominator, but no numerator, e.g., /c, that are not part of the above
referenced ISO standards. We have extended the units table to better
accommodate drug routes and physiologic measures, and otherwise fill in gaps in
Version 2.2.
We have generally followed the IUPAC 1995 Silver Book2 in the
definitions of units. However, IUPAC specifies standards for reporting or
displaying units and employs 8-bit data sets to distinguish them. This Standard
is concerned with the transmission of patient information. Therefore, we
have restricted ourselves to case insensitive alphabetic characters and a few
special characters (e.g., ".", "/", "(", ")", "*", and "_") to avoid any
possible confusion in the transmission. Therefore, we use ISO 2955-1983
(Information processing -- representation of SI and other units in systems with
limited character sets) and ANSI X3.50-1986 (Representations for U.S.
customary, SI, and other units to be used in systems with limited character
sets) case insensitive units abbreviations where they are defined. This means
that in some cases, IUPAC abbreviations have different abbreviations in ISO+
even when the IUPAC abbreviations use only standard alphabetic characters. For
example, Pascal is abbreviated Pa in IUPAC but PAL in ISO+
(following ISO 2955) because Pa in a case insensitive context also means
Picoampere. However, the requirements for transmission do not preclude
usage of IUPAC standards for presentation on paper or video display reports to
end-users.
All unit abbreviations are case insensitive. One could write milliliters as ML,
ml, or mL. In this table we have used lower case for all of the abbreviations
except for the letter L which we represent in upper case so that readers
will not confuse it with the numeral one (1). This is just a change in
presentation, not a change in the Standard. Systems should continue to
send the codes as upper or lower case as they always have.
Refer to section 7.18.4 for the contents of figure 7-9 - Common ISO derived
units & ISO+ extensions.
Local codes can be used for the units by indicating the code source of 99zzz in the third component (where 99zzz is an alpha-numeric string). In the case of local codes, the text name of the codes or the description of the units should also be transmitted (in the second component), so that the receiving system can compare the results with results for the same measurement sent by another service (refer to Chapter 2, Section 2.9, "Data Types"). An "L" should be stored in the third component to indicate that the code is locally defined. More specialized local code designations, as specified in the CE data type definition, can also be employed.
Components:
for numeric values in the format:
d) lower limit-upper limit (when both lower and upper limits are defined, e.g.,
for potassium 3.5 - 4.5)
e) > lower limit (if no upper limit, e.g., >10)
f) < upper limit (if no lower limit, e.g., <15)
alphabetical values: the normal value may be reported in this location
Definition: When the observation quantifies the amount of a toxic substance,
then the upper limit of the range identifies the toxic limit. If the
observation quantifies a drug, the lower limits identify the lower therapeutic
bounds and the upper limits represent the upper therapeutic bounds above which
toxic side effects are common.
Definition:
This field contains a table lookup indicating the normalcy status of the
result. We strongly recommend sending this value when applicable. (See ASTM
1238 - review for more details). Refer to User-defined Table 0078 -
Abnormal flags for valid entries.
When the laboratory can discern the normal status of a textual report, such as
chest X-ray reports or microbiologic culture, these should be reported as N
when normal and A when abnormal. Multiple codes, e.g., abnormal and worse,
would be separated by a repeat delimiter, e.g., A~W.
Value |
Description |
|---|---|
L |
Below low normal |
H |
Above high normal |
LL |
Below lower panic limits |
HH |
Above upper panic limits |
< |
Below absolute low-off instrument scale |
> |
Above absolute high-off instrument scale |
N |
Normal (applies to non-numeric results) |
A |
Abnormal (applies to non-numeric results) |
AA |
Very abnormal (applies to non-numeric units, analogous to panic limits for numeric units) |
null |
No range defined, or normal ranges don't apply |
U |
Significant change up |
D |
Significant change down |
B |
Better--use when direction not relevant |
W |
Worse--use when direction not relevant |
S |
Susceptible. Indicates for microbiology susceptibilities only. |
R |
Resistant. Indicates for microbiology susceptibilities only. |
I |
Intermediate. Indicates for microbiology susceptibilities only. |
MS |
Moderately susceptible. Indicates for microbiology susceptibilities only. |
VS |
Very susceptible. Indicates for microbiology susceptibilities only. |
Results may also be reported in shorthand by reporting the normalcy status without specifying the exact numeric value of the result. Such shorthand is quite common in clinical notes, where physicians will simply say that the glucose result was normal. Such shorthand reporting is also seen in drug experience reporting. In such cases, the result can be reported in the OBX by reporting the normalcy code in OBX-8-abnormal flags without specifying any value in OBX-5-observation value.
Definition: This field contains the probability of a result being true for results with categorical values. It mainly applies to discrete coded results. It is a decimal number represented as an ASCII string that must be between 0 and 1, inclusive.
Definition:
This field contains the nature of the abnormal test. Refer to HL7 Table
0080 - Nature of abnormal testing for valid values. As many of the
codes as apply may be included, separated by repeat delimiters. For example,
normal values based on age, sex, and race would be codes as A~S~R.
Value |
Description |
|---|---|
A |
An age-based population |
N |
None - generic normal range |
R |
A race-based population |
S |
A sex-based population |
Definition:
This field contains the observation result status. Refer to HL7 table 0085
- Observation result status codes interpretation for valid values.
This field reflects the current completion status of the results for one
Observation Identifier.
It is a required field. Previous versions of HL7 stated this implicitly by
defining a default value of "F." Code F indicates that the result has
been verified to be correct and final. Code W indicates that the result
has been verified to be wrong (incorrect); a replacement (corrected) result may
be transmitted later. Code C indicates that data contained in the
OBX-5-observation value field are to replace previously transmitted
(verified and) final result data with the same observation ID (including
suffix, if applicable) and observation sub-ID usually because the previous
results were wrong. Code D indicates that data previously transmitted
in a result segment with the same observation ID (including suffix) and
observation sub-ID should be deleted. When changing or deleting a result,
multiple OBX segments with the same observation ID and observation sub-ID are
replaced or deleted as a unit. Normal progression of results through
intermediate (e.g., `gram positive cocci') to final (e.g., `staphylococcus
aureus') should not be transmitted as C (correction); they should be
transmitted as P or S (depending upon the specific case) until
they are final.
There are situations where the observation battery required for the order needs
to be dynamically specified at the time of ordering. That is, this battery is
then defined by the set of OBX segments transmitted along with the order and
generated by the placing system. For example, timed measurements of
serum glucose challenge tests may vary among laboratories. One institution may
report them at -30, -15, 0, 30, 60, and 120 minutes, while another may report
them at -30, 0, 30, 60, 90, and 120 minutes. Master file entries may exist for
each individual element of the battery but not for the battery itself. Another
example may be Renin Studies where the specification may be done upon ordering
without having a master file definition for each permutation of the possible
element. The OBX segments in the ORM message can be used to create dynamic
specifications to accommodate these permutations without defining pre-existing
master file definitions for the battery itself. The result status field in the
OBX can be used to indicate whether the OBX in the ORM message is used to
provide a dynamic specification or is used to communicate a result as context
to the order. The status of O shall be used to indicate that the OBX segment is
used for a dynamic specification of the required result. An OBX used for a
dynamic specification must contain the detailed examination code, units, etc.,
with OBX-11 valued with O, and OBX-2 and OBX-5 valued with
null.
Value |
Description |
|---|---|
C |
Record coming over is a correction and thus replaces a final result |
D |
Deletes the OBX record |
F |
Final results; Can only be changed with a corrected result. |
I |
Specimen in lab; results pending |
N |
Not asked; used to affirmatively document that the observation identified in the OBX was not sought when the universal service ID in OBR-4 implies that it would be sought. |
O |
Order detail description only (no result) |
P |
Preliminary results |
R |
Results entered -- not verified |
S |
Partial results |
X |
Results cannot be obtained for this observation |
U |
Results status change to final without retransmitting results already sent as `preliminary.' E.g., radiology changes status from preliminary to final |
W |
Post original as wrong, e.g., transmitted for wrong patient |
Definition:
This field contains the changes in the observation methods that would make
values obtained from the old method not comparable with those obtained from the
new method.
Null if there are no normals or units. If present, a change in this date
compared to date-time recorded, the receiving system's test dictionary should
trigger a manual review of the results to determine whether the new observation
ID should be assigned a new ID in the local system to distinguish the new
results from the old.
Definition:
This field permits the producer to record results-dependent codes for
classifying the observation at the receiving system. This field should be
needed only rarely, because most classifications are fixed attributes of the
observation ID and can be defined in the associated observation master file
(see description in Chapter 8).
However, there are a few cases when such controls vary with the value of the
observation in a complex way that the receiving system would not want to
re-calculate. An example is an antimicrobial susceptibility result. Some
systems prefer to display only the susceptibility results of inexpensive
antimicrobials depending upon the organism, the source of the specimen and the
patient's allergy status. The sending service wants to send all of the
susceptibilities so that certain privileged users (e.g., Infectious Disease
specialists) can review all of the results but nonprivileged users would see
only the "preferred" antimicrobials to which the organism was susceptible. We
expect that other cases also occur.
Definition:
This field is required in two circumstances. The first is when the
observations reported beneath one report header (OBR) have different
dates/times. This could occur in the case of queries, timed test sequences, or
clearance studies where one measurement within a battery may have a different
time than another measurement.
It is also needed in the case of OBX segments that are being sent by the placer
to the filler, in which case the date of the observation being transmitted is
likely to have no relation to the date of the requested observation. In
France, requesting services routinely send a set of the last observations along
with the request for a new set of observations. The date of these observations
is important to the filler laboratories.
In all cases, the observation date-time is the physiologically relevant
date-time or the closest approximation to that date-time. In the case of tests
performed on specimens, the relevant date-time is the specimen's collection
date-time. In the case of observations taken directly on the patient (e.g.,
X-ray images, history and physical), the observation date-time is the date-time
that the observation was performed.
Components:
<identifier (ST)> ^ <text (ST)> ^ <name of coding system
(IS)> ^ <alternate identifier (ST)> ^ <alternate text (ST)> ^
<name of alternate coding system (IS)>
Definition: This field contains a unique identifier of the responsible
producing service. It should be reported explicitly when the test results are
produced at outside laboratories, for example. When this field is null, the
receiving system assumes that the observations were produced by the sending
organization. This information supports CLIA regulations in the US. The code
for producer ID is recorded as a CE data type. In the US, the Medicare number
of the producing service is suggested as the identifier.
Components:
In Version 2.3 and later, use instead of the CN data type. <ID number
(ST)> ^ <family name (FN)> ^ <given name (ST)> ^ <second or
further given names or initials thereof (ST)> ^ <suffix (e.g., JR or III)
(ST)> ^ <prefix (e.g., DR) (ST)> ^ <degree (e.g., MD) (IS)> ^
<source table (IS)> ^ <assigning authority (HD)> ^ <name type
code (ID)> ^ <identifier check digit (ST)> ^ <code identifying the
check digit scheme employed (ID)> ^ <identifier type code (IS)> ^
<assigning facility (HD)> ^ <name representation code (ID)> ^
<name context (CE)> ^ <name validity range (DR)> ^ < name
assembly order (ID)>
Subcomponents of assigning authority: <namespace ID (IS)> &
<universal ID (ST)> & <universal ID type (ID)>
Subcomponents of assigning facility ID: <namespace ID (IS)> &
<universal ID (ST)> & <universal ID type (ID)>
Definition: When required, this field contains the identifier of the
individual directly responsible for the observation (i.e., the person who
either performed or verified it). In a nursing service, the observer is
usually the professional who performed the observation (e.g., took the blood
pressure). In a laboratory, the observer is the technician who performed or
verified the analysis. The code for the observer is recorded as a CE data
type. If the code is sent as a local code, it should be unique and unambiguous
when combined with OBX-15-producer ID.
Components:
<identifier (ST)> ^ <text (ST)> ^ <name of coding system
(IS)> ^ <alternate identifier (ST)> ^ <alternate text (ST)> ^
<name of alternate coding system (IS)>
This optional field can be used to transmit the method or procedure by which an
observation was obtained when the sending system wishes to distinguish among
one measurement obtained by different methods and the distinction is not
implicit in the test ID. Chemistry laboratories do not usually distinguish
between two different methods used to measure a given serum constituent (e.g.,
serum potassium) as part of the test name. See the LOINC® Users Manual[3] for a more complete discussion of these
distinctions. If an observation producing service wanted to report the method
used to obtain a particular observation, and the method was NOT embedded in the
test name, they can use this field.
The Centers for Disease Control and Prevention (CDC) Method Code (CDCM) (see
Figure 7-3) is one candidate code system for reporting methods/instruments.
EUCLIDES method codes are another. User-defined tables are an alternative.
Components:
<entity identifier (ST)> ^ <namespace ID (IS)> ^ <universal ID
(ST)> ^ <universal ID type (ID)>
Definition: This field identifies the Equipment Instance (e.g., Analyzer,
Analyzer module, group of Analyzers,...) responsible for the production of the
observation. This is the identifier from an institution's master list of
equipment, where the institution is specified by the namespace ID or if
it is blank, then by the "Producer's ID" (OBX-15). It should be possible to
retrieve from this master list the equipment type, serial number, etc., however
it is not planned to transfer this information with every OBX. The repeating of
this field allows for the hierarchical representation of the equipment (lowest
level first), e.g., module of an instrument, instrument consisting of modules,
cluster of multiple instruments, etc.
Definition: This field is used to transfer the time stamp associated with generation of the analytical result by the instrument specified in Equipment Instance Identifier (see above).
The
following is a query of the EKG system for the data for a particular patient
number 0123456-1 for reports that have been modified or created since 1/1/88.
These examples use LOINC® clinical codes. The response ends with a
continuation pointer. A continuation query follows, in reply to which a
continuation response is sent.
Query (QRY)
MSH|^~\&|CBD||EKG||198905201200||QRY^R02|CDB22222|P|...<cr>
QRD|198904180943|R|I|Q4412|||10|RD|0123456-1|RES|...<cr>
QRF|EKG||198801010000|...<cr>
Response
MSH|^~\&|EKG||CDB||198905201201||ORF^R04|X981672|P|...<cr>
MSA|AA|CDB22222|P|...<cr>
QRD|198904180943|R|I|Q4412|||10|RD|0123456-1|RES|...<cr>
QRF|EKG||198804010000|...<cr>
PID|1||0123456-1||ROBERTSON^JOHN^H||||||||982-1111|...<cr>
OBR|1|43215^OE|98765^EKG|93000^EKG REPORT|
||198801111330|||1235^TAYLOR^ROBERT^M||||
198801111330||P030||||||198801120930||||||P011^PRESLEY^ELVIS^AARON^^^MD|43214^OE|...<cr>
OBX|1|ST|8897-1^QRS COMPLEX^LN||91|/MIN|60-100||||F|...<cr>
OBX|2|ST|8894-8^P WAVE^LN||92|/MIN|60-100||||F|...<cr>
OBX|3|ST|8625-6^P-R INTERVAL^LN||0|/MSEC|1.06-.10||||F|...<cr>
OBX|4|ST|8633-0^QRS DURATION^LN||.368|/MSEC|.18-.22||||F|...<cr>
...
...
...
OBX|8|CE|8601-7^EKG IMPRESSION^LN|1|^ATRIAL FIBRILATION||||||F|...<cr>
OBX|9|CE|8601-7^EKG IMPRESSION^LN|2|^ST DEPRESSION||||||F|...<cr>
OBX|10|FT|93000&ADT^EKG COMMENT||\.in+4\\.ti-4\ 1. When compared with EKG
of
31-oct-88 ventricular rate has increased by 30 bpm.\.sp\\.ti-4\
2. Criteria for Lateral infarct are no longer present.|||||F|...<cr>
OBR|2|43217^OE|98767^EKG|93000^EKG
REPORT|||198810311004|||||||198810311004||P030||||||198810311744||||||
P011^PRESLEY^ELVIS^AARON^^^MD |43213^OE |...<cr>
...
...
...
DSC|1896X22;0123456-1|...<cr>
Continuation query
MSH|^~\&|CDB||EKG||198905201204||QRY^R02|CDB22289|P|...<cr>
QRD|198904180943|R|I|Q4412|||10|RD|0123456-1|RES|...<cr>
QRF|EKG||1988040100000|...<cr>
DSC|1896X22;0123456-1|...<cr>
Continuation response
MSH|^~\&|EKG||CDB||198905201205||ORF^R04|X981672|P|...<cr>
MSA|AA|CDB22289|P|...<cr>
QRD|198904180943|R|I|Q4412|||10|RD|0123456-1|RES|...<cr>
QRF|EKG||198804010000|...<cr>
PID|1||0123456-1||ROBERTSON^JOHN^H||||||||982-1111|...<cr>
OBR| ...<cr>
The
following is an unsolicited transmission of radiology data.
MSH|^~\&|XRAY||CDB||200006021411||ORU^R01|K172|P|...<cr>
PID|...<cr>
OBR|1|X89-1501^OE|78912^RD|71020^CHEST XRAY AP \T\
LATERAL|||19873290800|||9218^MASTERS^JOHN^B|...<cr>
OBX|1|CE|71020&IMP^RADIOLOGIST'S IMPRESSION|4|^MASS LEFT LOWER
LOBE|||A|||F|...<cr>
OBX|2|CE|71020&IMP|2|^INFILTRATE RIGHT LOWER LOBE|||A|||F|...<cr>
OBX|3|CE|71020&IMP|3|^HEART SIZE NORMAL|||N|||F|...<cr>
OBX|4|FT|71020&GDT|1|circular density (2 x 2 cm) is seen in the posterior
segment of
the LLL. A second, less well-defined infiltrated circulation density is
seen in the R mid lung field and appears to cross the minor
fissure#||||||F|...<cr>
OBX|5|CE|71020&REC|5|71020^Follow up CXR 1 month||30-45||||F|...<cr>
Laboratory
message: electrolytes, CBC, sed rate, blood cultures and susceptibilities
MSH|...<cr>
PID|...<cr>
Electrolytes:
OBR|1|870930010^OE|CM3562^LAB|2432-6^ELECTROLYTES HCFA 98 PANEL^LN|
||198703290800|||
401-0^INTERN^JOE^^^^MD^L| ||||SER|^SMITH^RICHARD^W.^^^DR.|(319)377-4400|
This is requestor field #1.|Requestor field #2|Diag.serv.field #1.|
Diag.serv.field #2.|198703311400|||F|...<cr>
OBX|1|NM|2951-2^SODIUM^LN||150|mmol/L|136-148|H||A|F|19850301|...<cr>
OBX|2|NM|2823-3^POTASSIUM^LN||4.5|mmol/L|3.5-5|N||N|F|19850301|...<cr>
OBX|3|NM|2075-0^CHLORIDE^LN||102|mmol/L|94-105|N||N|F|19850301|...<cr>
OBX|4|NM|2028-9^CARBON
DIOXIDE^LN||27|mmol/L|24-31|N||N|F|19850301|...<cr>
CBC:
OBR|2|870930011^OE|HEM3268^LAB|24359-2HEMOGRAM+DIFFERENTIAL PANEL^LN|
||198703290800|||401-0 ^
INTERN^JOE^^^^MD^L|||||BLDV|^SMITH^RICHARD^W.^^^DR.|(319)377-4400|This is
requestor field #1.|This is Requestor field #2.|This is lab field #1.|Lab field
#2.|198703311400|||F|...<cr>
OBX|1|NM|718-7^HEMOGLOBIN^LN||13.4|GM/DL|14-18|N||S|F|19860522|...<cr>
OBX|2|NM|4544-3^HEMATOCRIT^LN||40.3|%|42-52|L||S|F|19860522|...<cr>
OBX|3|NM|789-8^ERYTHROCYTES^LN||4.56|10*6/ml|4.7-6.1|L||S|F|19860522|...<cr>
OBX|4|NM|787-2^ERYTHROCYTE MEAN CORPUSCULAR VOLUME:^LN
||88|fl|80-94|N||S|F|19860522|...<cr>
OBX|5|NM|785-6^ERYTHROCYTE MEAN CORPUSCULAR HEMOGLOBIN:^LN
||29.5|pg|27-31|N||N|F|19860522|...<cr>
OBX|6|NM|786-4^ERYTHROCYTE MEAN CORPUSCULAR HEMOGLOBIN CONCENTRATION:^LN
||33|%|33-37|N||N|F|19860522|...<cr>
OBX|7|NM|6690-2^LEUKOCYTES^LN||10.7|10*3/ml|4.8-10.8|N||N|F|19860522|...<cr>
OBX|8|NM|770-8^NEUTROPHILS/100 LEUKOCYTES^LN/100
LEUKOCYTES:^LN||68|%|||||F|...<cr>
OBX|9|NM|736-9^LYMPHOCYTES/100 LEUKOCYTES:^LN||29|%|||||F|...<cr>
OBX|10|NM|5905-5^MONOCYTES/100 LEUKOCYTES:^LN||1|%|||||F|...<cr>
OBX|11|NM|713-8^EOSINOPHILS/100 LEUKOCYTES:^LN||2|%|||||F|...<cr>
Sed rate:
OBR|3|870930011^OE|HEM3269^LAB|4537-7^ERYTHROCYTE SEDIMENTATION RATE^LN
|||198703290800|||
401-0^INTERN^JOE^^^^MD^L|||||BLDV|^SMITH^RICHARD^W.^^^DR.|(319)377-4400|
This is requestor field #1.|This is Requestor field #2.|This is lab field
#1.|Lab field #2.|198703311400|||F|...<cr>
OBX|1|NM|4537-7^ERYTHROCYTE SEDIMENTATION RATE:^LN|
|7|MM/HR|0-10|N||S|F|19860522|...<cr>
Parent micro result, identifies organism
OBR|4|2740X^OE|BC376^MIC|87040^Blood culture| ||198703290800|||
99-2^JONES^COLLECTOR||^Hepatitis risk||198703290830|BLDV|
4010^INTERN^JOE^^^^MD^L|321-4321 X3472^^^^^^^3472|Requestor field 1|Requestor
field 2|
Producer's field 1|Producer's field 2|198703301000|35.00|MB|F|...<cr>
OBX|1|CE|600-7^MICROORGANISM IDENTIFIED^LN|1|^E Coli|||A|||F|...<cr>
OBX|2|CE|600-7^MICROORGANISM IDENTIFIED^LN|2|^S Aureus|||A|||F|...<cr>
Child micro result, gives antimicrobials susceptibilities for organism
identified in first OBX of parent
OBR|5|2740X^OE|BC402^MIC|87186^Antibiotic MIC||
|198703290800||||G|^Hepatitis Risk||198703290830|BLDB
|401.0^INTERN^JOE^^^^MD^L|321-4321 X3472^^^^^^^3472|||||198703310900|40.00
|MB|F|600-7&MICROORGANISM
IDENTIFIED&LN^1|||2740X&OE^BC376&MIC|...<cr>
OBX|1|ST|28-1^AMIPICILLIN:SUSC:PT:ISLT:QN:MIC^LN||<2|ug/ml||S|||F|...<cr>
OBX|2|ST|60-4^CARBENICILLIN:SUSC:PT:ISLT:QN:MIC^LN||<16|ug/ml||S|||F|...<cr>
OBX|3|ST|267-5^GENTAMICIN:SUSC:PT:ISLT:QN:MIC^LN||<2|ug/ml||S|||F|...<cr>
OBX|4|ST|496-0^TETRACYCLINE:SUSC:PT:ISLT:QN:MIC^LN||<1|ug/ml||S|||F|...<cr>
OBX|5|ST|408-5^PIPERACILLIN:SUSC:PT:ISLT:QN:MIC^LN||<8|ug/ml||S|||F|...<cr>
OBX|6|ST|145-3^CEFUROXIME:SUSC:PT:ISLT:QN:MIC^LN||<2|ug/ml||S|||F|...<cr>
OBX|7|ST|161-0^CEPHALOTHIN:SUSC:PT:ISLT:QN:MIC^LN||<8|ug/ml||S|||F|...<cr>
OBX|8|ST|20-8^AMOXICILLIN+CLAVULANATE:SUSC:PT:ISLT:QN:MIC^LN
||<4|ug/ml||S|||F|...<cr>
OBX|9|ST|173-5^CHLORAMPHENICOL:SUSC:PT:ISLT:QN:MIC^LN||<4|ug/ml||S|||F|...<cr>
OBX|10|ST|508-2^TOBRAMYCIN:SUSC:PT:ISLT:QN:MIC^LN||<2|ug/ml||S|||F|...<cr>
OBX|11|ST|12-5^AMIKACIN:SUSC:PT:ISLT:QN:MIC^LN||<4|ug/ml||S|||F|...<cr>
OBX|12|ST|516-5^TRIMETHOPRIM+SULFMOETHOXAZOLE:SUSC:PT:ISLT:QN:MIC^LN|
|<2/38|ug/ml||S|||F|...<cr>
OBX|13|ST|76-0^CEFAZOLIN:SUSC:PT:ISLT:QN:MIC^LN||<2|ug/ml||S|||F|...<cr>
OBX|14|ST|116-4^CEFOXITIN:SUSC:PT:ISLT:QN:MIC^LN||<2|ug/ml||S|||F|...<cr>
OBX|15|ST|141-2^CEFTRIAXONE:SUSC:PT:ISLT:QN:MIC^LN||<4|ug/ml||S|||F|...<cr>
OBX|16|ST|133-9^CEFTAZIDIME:SUSC:PT:ISLT:QN:MIC^LN||<2|ug/ml||S|||F|...<cr>
OBX|17|ST|185-9^CIPROFLOXACIN:SUSC:PT:ISLT:QN:MIC^LN||<1|ug/ml||S|||F|...<cr>
Second micro child result, gives susceptibilities or organism identified by
Second OBX of parent
OBR|6|2740X^OE|BC403^MIC|87186^Antibiotic MIC| ||198703290800||||G|
^Hepatitis risk||198703290830|BLDV|401.0^INTERN^JOE^^^^MD^L|321-4321
X3472^^^^^^^3472|||||
198703310900|40.00|MB|F|600-7&MICROORGANISM IDENTIFIED &LN^2|
||2740X&OE^BC376&MIC|...<cr>
OBX|1|ST|28-1^AMPICILLIN:SUSC:PT:ISLT:QN:MIC^LN||<8|ug/ml||R|||F|...<cr>
OBX|2|ST|193-3^CLINDAMYCIN:SUSC:PT:ISLT:QN:MIC^LN||<.25|ug/ml||S|||F|...<cr>
OBX|3|ST|267-5^GENTAMICIN:SUSC:PT:ISLT:QN:MIC^LN||<1|ug/ml||S|||F|...<cr>
OBX|4|ST|233-7^ERYTHROMYCIN:SUSC:PT:ISLT:QN:MIC^LN||<.5|ug/ml||S|||F|...<cr>
OBX|5|ST|383-0^OXACILLIN:SUSC:PT:ISLT:QN:MIC^LN||<.5|ug/ml||S|||F|...<cr>
OBX|6|ST|524-9^VANCOMYCIN:SUSC:PT:ISLT:QN:MIC^LN||<2|ug/ml||S|||F|...<cr>
OBX|7|ST|6932-8^PENICILLIN:SUSC:PT:ISLT:QN:MIC^LN||<8|ug/ml||R|||F|...<cr>
OBX|8|ST|161-0^CEPHALOTHIN:SUSC:PT:ISLT:QN:MIC^LN||<2|ug/ml||S|||F|...<cr>
OBX|9|ST|173-5^CHLORAMPHENICOL:SUSC:PT:ISLT:QN:MIC^LN||<4|ug/ml||S|||F|...<cr>
OBX|10|ST|12-5^AMIKACIN:SUSC:PT:ISLT:QN:MIC^LN||<16|ug/ml||S|||F|...<cr>
OBX|11|ST|185-9^CIPROFLOXACIN:SUSC:PT:ISLT:QN:MIC^LN||<1|ug/ml||S|||F|...<cr>
OBX|12|ST|428-3^RIFAMPIN:SUSC:PT:ISLT:QN:MIC^LN||<1|ug/ml||S|||F|...<cr>
This
example of the body of reports shows the following observation from what are
usually free text reports. The text within these examples that begins with
**-- and ends with --** are explanatory comments, not a formal part of the
message. The following outline shows the segments that are included in this
example message.
a) patient identifying record (PID)
b) EKG order record (OBR)
c) EKG coded result record (OBX)
d) EKG result records (OBX):
1) ventricular rate
2) atrial rate
3) QRS width
4) PR interval
e) order record for chest x-ray (OBR)
f) two diagnostic impressions for CXR (OBX)
g) description record for CXR (OBX)
h) a recommendation record for CXR (OBX)
i) an order record for surgical pathology (OBR)
j) a gross description record for pathology showing use of anatomy fields
(OBX)
k) a microscopic description record for pathology (OBX)
l) vital signs request (OBR)
m) six vital signs (OBX)
n) part of the physical history (OBR & OBX)
o) end record
MSH|...<cr>
PID|...<cr>
Order record for EKG
OBR|1|P8753^OE|EK5230^EKG|93000^EKG|||198703290800|||401
0^INTERN^JOE^^^^MD^L|...<cr>
Two interpretation records for EKG
OBX|1|CE|93000&IMP^EKG|1|^Sinus bradycardia|||A|||F|...<cr>
OBX|2|CE|93000&IMP^EKG|2|^Occasional PVCs|||A|||F|...<cr>
Four numeric results for EKG
OBX|3|NM|8897-1^QRS COMPLEX RATE ^LN|
|80|/min|60-100|||||F|...<cr>
OBX|4|NM|8894-8^PULSE RATE^LN||80|/min
|60-100||||F|...<cr>
OBX|5|NM|8633-0^QRS DURATION ^LN||.08|msec
|.06-.10||||F|...<cr>