8 . Master Files

Chapter Chair

Mike Henderson Eastern Informatics

Chapter Chair

Doug Pratt Siemens Medical Solutions Health Services Corporation

Chapter Chair (outgoing)

Larry Reis Consultant

Chapter Chair

Mark Shafarman Oracle

Chapter Chair (incoming)

Joann Larson Kaiser Permanente

Editor

Klaus D. Veil HL7S&S

Editor

Jim Kingsland McKesson Information Solutions

The content of this chapter is "owned" by various Technical Committees as listed below:

Steward Committee

Message

Segment

Control/Query

M01, M13, M14

MFI, MFE, MFA

PA

M05

LOC, LCH, LRL, LDP, LCH, LCC

FM

M04

CDM, PRC

Personnel Management

M02

STF, PRA, ORG, AFF, EDU, LAN, CER

Orders/Observations

M03, M08, M09, M10, M11, M12, M15

OM1, OM2, OM3 , OM4, OM5, OM6, OM7, IIM

Orders/Observations (Clinical Trials)

M06, M07

CM0, CM1, CM2

8.1 CHAPTER 8 CONTENTS

8.2 PURPOSE

In an open-architecture healthcare environment there often exists a set of common reference files used by one or more application systems. Such files are called master files. Some common examples of master files in the healthcare environment include:

1. staff and health practitioner master file

2. system user (and password) master file

3. location (census and clinic) master file

4. device type and location (e.g., workstations, terminals, printers, etc.)

5. lab test definition file

6. exam code (radiology) definition file

7. charge master file

8. patient status master

9. patient type master

10. service item master file

These common reference files need to be synchronized across the various applications at a given site. The Master Files Notification message provides a way of maintaining this synchronization by specifying a standard for the transmission of this data between applications.

In many implementations, one application system will "own" a particular master file such as the staff and practitioner master file. The changes (e.g., adds, deletes, updates) to this file are made available to various other applications on a routine basis. The Master Files Notification message supports this common case, but also supports the situation where an application not "owning" a particular master file, transmits update information to other systems (usually to the "owning" system), for review and possible inclusion.

The Master Files Notification message supports the distribution of changes to various master files between systems in either online or batch modes, and allows the use of either original or enhanced acknowledgment modes, as well as providing for a delayed application acknowledgment mode. These messages use the MSH segment to pass the basic event code (master files notification or acknowledgment). The MFI (master file identification) segment identifies the master file being updated as well as the initial and requested dates for "file-level" events (such as "replace file"). For each record being changed, the MFE (Master File Entry) segment carries the record-level event code (such as add, update, etc.), the initial and requested dates for the event, and the record-level key identifying the entry in the master file. The MFA (master file acknowledgment) segment returns record-specific acknowledgment information.

Note: The MFE segment is not the master file record, but only specifies its identifier, event, and event dates. The master file record so identified is contained in either Z-segments or HL7-defined segments immediately following the MFE segment. This record may be either a flat record contained in a single segment, or a complex record needing more than a single segment to carry its data and (usually hierarchical) structure.

The master file segments commonly needed across HL7 applications as well as those specific to the various application chapters, are defined in Sections 8.7, STAFF AND PRACTITIONER MASTER FILES, through 8.11, CLINICAL TRIALS MASTER FILES of this chapter.

Note: Some segments previously defined in this chapter have been moved to Chapter 15 - Personnel Management. See Section 8.7, STAFF AND PRACTITIONER MASTER FILES

A given master files message concerns only a single master file. However, the provision of a record-level event code (and requested activation date) on the MFE and the MFA segments allows a single message to contain several types of changes (events) to that file.

The Master Files Notification events do not specify whether the receiving system must support an automated change of the master file in question, nor do they specify whether the receiving system must create a file in the same form as that maintained on the sending system.

In general, the way in which the receiving system processes the change notification message will depend on both the design of the receiving system and the requirements negotiated at the site. Some systems and/or sites may specify a manual review of all changes to a particular master file. Some may specify a totally automated process. Not every system at every site will need all the fields contained in the master file segment(s) following the MFE segment for a particular master file entry.

This also means that an application acknowledgment (or a deferred application acknowledgment) from a receiving system that it changed a particular record in its version of the master file does not imply that the receiving system now has an exact copy of the information and state that is on the sending system: it means only that whatever subset of that master file_s data (and state) that has been negotiated at the site is kept on the receiving system in such a manner that a new Master Files Notification transaction with the same primary key can be applied unambiguously (in the manner negotiated at the site) to that subset of information.

8.3 TRIGGER EVENTS

The Master Files Change Notification message can be used for the following message-level trigger events:

Mnn: A message containing notifications of changes to a single master file.

nn defines a particular HL7 master file. Currently-defined values are (see HL7 table 0003 - Event Type): M01 - master file not otherwise specified (for backward compatibility only); M02 - staff/practitioner master file; M03 - service/test/observation master file (for backward compatibility only); M04 - charge description master file; M05 - location master file; M06 - M07 - clinical study master file; M08 - M12 - service/text/observation master file; M13 - General Master File; M14 - Site Defined Master File; M15 - Inventory Item Master File, M16 - M99 - reserved for future HL7-defined master files. It is recommended that site-specific master files use event M13 or M14; alternately a code of the form Znn can be used. (See also Section 8.5.1.0, MFI ).

A MFN message may contain the following "file-level" events, as specified in the MFI segment:

REP: Replace current version of this master file with the version contained in this message.

UPD: Change file records as defined in the record-level event codes for each record that follows.

These are the only file-level events currently defined. REP means that every MFE segment that follows will use the MAD event code.

The replace option allows the sending system to replace a file without sending delete record-level events for each record in that file. UPD means that the events are defined according to the record-level event code contained in each MFE segment in that message.

An MFN message may contain the following "record-level" events, as specified in the MFE segments.

MAD: Add record to master file.

MDL: Delete record from master file.

MUP: Update record for master file.

MDC: Deactivate: discontinue using record in master file, but do not delete from database.

MAC: Reactivate deactivated record.

The MFD transaction is used for the following trigger event:

MFA: Master Files Delayed Application Acknowledgment.

8.4 MESSAGES

The following messages are defined for master files transactions: MFN, master files notification; MFK, master files application acknowledgment; MFD, master files delayed application acknowledgment; and MFQ, master files query.

8.4.1 MFN/MFK - Master File Notification (Event M01)

The MFN transaction is defined as follows:

Note: MFN^M01 is retained for backward compatibility only. It is recommended that the specific non-deprecated master file messages that follow be used as they apply to new implementations (such as MFN^M02, MFN^M08, MFN^M09, etc.).

MFK^M01^MFK_M01	Master File Application Acknowledgment	Status	Chapter	DB Ref.
MSH	Message Header		2	DB
[ { SFT } ]	Software		2	DB
MSA	Acknowledgment		2	DB
[ { ERR } ]	Error		2	DB
MFI	Master File Identification		8	DB
[ { MFA } ]	Master File ACK segment		8	DB

Note: The MFK message is used for an application acknowledgment in either the original or enhanced acknowledgment modes.

8.4.1.0

8.4.1.1 MFN use notes

The master file record identified by the field MFE-4 - Primary Key Value - MFE is contained in either Z-segments and/or HL7-defined segments immediately following the MFE segment, and is denoted by "..." in the MFN abstract message definition given above. This record may be either a flat record contained in a single segment, or a complex record needing more than a single segment to carry its data and (usually hierarchical) structure.

The master file segment(s) "[...]" identified by the MFE segment are optional (indicated by square brackets) in the single case where the master file is a simple one that contains only a key and the text value of that key. For this case only, both values may be carried in MFE-4 - Primary Key Value - MFE.

8.4.1.2 MFK use notes

The MFA segment carries acknowledgment information for the corresponding MFE segment. Fields MFE-4 - Primary Key Value - MFE and MFA-5 - Primary Key Value - MFA provide the link between the corresponding segments.

8.4.2 MFN/MFK - Master File Notification - General (Event M13)

The MFN General master file notification transaction is used where the master file is a simple one that contains only a key and the text value of that key. Both values are carried in MFE-4 - Primary Key Value - MFE. The specific master file being updated is identified by MFI-1 - Master File Identifier and MFI-2 - Master Files Application Identifier.

The General master file notification is defined as follows:

MFK^M13^MFK_M01	Master File Application Acknowledgment	Status	Chapter	DB Ref.
MSH	Message Header		2	DB
[ { SFT } ]	Software		2	DB
MSA	Acknowledgment		2	DB
[ { ERR } ]	Error		2	DB
MFI	Master File Identification		8	DB
[ { MFA } ]	Master File ACK segment		8	DB

Note: The MFK message is used for an application acknowledgment in either the original or enhanced acknowledgment modes.

8.4.2.0

8.4.2.1 MFK use notes

The MFA segment carries acknowledgment information for the corresponding MFE segment (identified by MFA-5 - Primary Key Value - MFA). Fields MFE-4 - Primary Key Value - MFE and MFA-5 - Primary Key Value - MFA provide the link between the corresponding segments.

8.4.3 MFN/MFK - Master File Notification - Site Defined (Event M14)

The MFN Site defined master file notification transaction is used where the master file is not a simple one (as defined for MFN^M13) and is not a transaction type currently defined by HL7, but rather requires one or more HL7 and/or _Z_ segments to carry the master file information.

The Site defined master file notification is defined as follows:

MFK^M14^MFK_M01	Master File Application Acknowledgment	Status	Chapter	DB Ref.
MSH	Message Header		2	DB
[ { SFT } ]	Software		2	DB
MSA	Acknowledgment		2	DB
[ { ERR } ]	Error		2	DB
MFI	Master File Identification		8	DB
[ { MFA } ]	Master File ACK segment		8	DB

Note: The MFK message is used for an application acknowledgment in either the original or enhanced acknowledgment modes.

8.4.3.0

8.4.3.1 MFN use notes

The master file record identified by the MFE segment is contained in Z-segments immediately following the MFE segment, and is denoted by ___ in the MFN abstract message definition given above. This record may be either a flat record contained in a single segment, or a complex record needing more than a single segment to carry its data and (usually hierarchical) structure.

The definition of this transaction and the associated abstract message structure code (as defined in MSH-9 - Message Type, denoted by MFN_Znn above) are subject to site negotiation. Refer to Chapter 2 for additional information on _Z_ abstract message structure code definition.

8.4.3.2 MFK use notes

The MFA segment carries acknowledgment information for the corresponding MFE segment (identified by MFA-5 - Primary Key Value - MFA). Fields MFE-4 - Primary Key Value - MFE and MFA-5 - Primary Key Value - MFA provide the link between the corresponding segments.

8.4.4 MFQ/MFR - Master Files Query (Event M01-M14)

The MFQ transaction allows a system to query for a particular record or group records (defined by the primary key) in a particular master file.

Note: The use of original mode queries such as the MFQ transaction should be deprecated in favor of conformance based queries as defined in Chapter 5. Refer to Section 8.4.6 for an example of a master file conformance based query.

The Master files query is defined as follows:

MFR^M01-M14^MFR_M01	Master Files Response	Status	Chapter	DB Ref.
MSH	Message Header		2	DB
[ { SFT } ]	Software		2	DB
MSA	Acknowledgment		2	DB
[ { ERR } ]	Error		2	DB
[ QAK ]	Query Acknowledgment		5	DB
QRD	Query Definition		5	DB
[ QRF ]	Query Filter		5	DB
MFI	Master File Name		8	DB
{	--- MF_QUERY begin
MFE	Master File Entry		8	DB
[ ... ]	One or more HL7 and/or Z-segments carrying the data for the entry identified in the MFE segment.		(varies)	DB
}	--- MF_QUERY end
[ DSC ]	Continuation		2	DB

8.4.4.1 MFQ use notes

The value "MFQ" of the QRD-9 - What Subject Filter of the QRD segment identifies a master files query. The QRD-10 - What Department Data Code of the QRD segment identifies the name of the master file in question. The QRD-11 - What Data Code Value Qual. of the QRD segment identifies the primary key (or keys, or range of keys) defining the master file MFE segments (and associated master file records, denoted by "_") to be returned with the response. The QRF segment may be used to define time ranges, particular MFN record-level event codes etc. Unless otherwise specified, the response returns only active current record(s).

8.4.5 Example Conformance Based Master File Query

The following is an example of a site-defined conformance based master file query. In this example, the user wishes to know information regarding a specific location on the Location Master File (as defined in Section 8.9). In an actual query conformance statement, the _Znn_ would be replaced by a _Z_ followed by the actual 2-digit number of the query.

8.4.5.0

8.4.5.1 Example of Conformance Statement for Location Master File query

Field Seq (Query ID=Znn)	Name	Key/ Search	Sort	LEN	TYPE	Opt	Rep	Match Op	TBL	Segment Field Name	Service Identifier Code	Element Name
1	MessageQueryName			250	CE	R				QPD-1		Message Query Name
2	QueryTag			32	ST	R				QPD-2		Query Tag
3	MasterFileIdentifier			250	CE	R				MFI-1		Master File Identifier
4	MasterFileApplicationIdentifier			180	HD	O				MFI-2		Master File Application Identifier
5	PrimaryKey			200	PL	R				MFE-4		Primary Key Value - MFE

Input Parameter (Query ID=Znn)	Comp. Name	DT	Description
MessageQueryName		CE	Components: ^ ^ ^ ^ ^
	identifier	ST	Must be valued Znn
	text	ST	Must be valued Find Location
	name of coding system	IS	Must be valued HL70471
QueryTag		ST	Must be valued with a unique identifier for this query message instance.
MasterFileIdentifier		CE	Components: ^ ^ ^ ^ ^
	identifier	ST	Must be valued LOC
	name of coding system	IS	Must be valued HL70175
MasterFileApplicationIdentifier		HD	Components: ^ ^
PrimaryKey		PL	Components: ^ ^ ^ ^ < location status (IS )> ^ ^ ^ ^
			This field contains the institution_s identification code for the location. At least the first component of this field is required. The first component can be an identifying code for the nursing station for inpatient locations, or clinic, department or home for patient locations other than inpatient ones.

Field Seq (Query ID=Znn)	Name	Component Name	LEN	DT	Description
1	Query Priority		1	ID	Must be valued I (Immediate).
3	Response modality		250	CE	Must be valued R (Real Time).

The following is an example of the use of the Location Master File query. The following query requests Location Master File information for nursing station 2N, room 101:

MSH|^~\&|BEDMGMT|HSP1|HIS|HSP1|200105311135||QBP^Znn^QBP_Q11|1|P|2.5

QPD|Znn^Find Location^HL70471|1022|LOC^Location Master^HL70175|HSP1|2N^101^^HSP1

RCP|I||R

The following is a sample response:

MSH|^~\&|HIS|HSP1|BEDMGMT|HSP1|200105311136||RSP^Znn^RSP_Q11|1|P|2.5|

MSA|AA|8699|

QAK|1022|OK| Znn^Find Location^HL70471|1|1|0

QPD|Znn^Find Location^HL70471|1022|LOC^Location Master^HL70175|HSP1|2N^101^^HSP1

MFE|MAD|||2N^101^^HSP1|PL

LOC|2N^101^^HSP1|Station 2 North, room 101|R||(407)804-5000||IVP|P

LCH|2N^101^^HSP1|||PRL^Privacy level^HL70324|S^Semi-private room^HL70262

LCH|2N^101^^HSP1|||SMK^Smoking^HL70324|Y^^HL70136

A single match was returned, as indicated in the QAK segment. The location definition and characteristics are returned in LOC and LCH segments.

8.5 GENERAL MASTER FILE SEGMENTS

The following segments are defined for the master files messages.

8.5.1 MFI - Master File Identification Segment

The Technical Steward for the MFI segment is CQ.

The fields in the MFI segment are defined in HL7 Attribute Table - MFI.

HL7 Attribute Table - MFI - Master File Identification

8.5.1.1 MFI-1 Master File Identifier (CE) 00658

Definition: This field is a CE data type that identifies a standard HL7 master file. This table may be extended by local agreement during implementation to cover site-specific master files (z-master files). HL7 recommends use of the HL7 assigned table number as the master file identifier code if one is not specified in Table 0175. For example, a master file of Marital Status codes would be identified by HL70002 as the MFI-1 - Master file identifier. Refer to HL7 table 0175 - Master file identifier code for valid values.

HL7 Table 0175 - Master file identifier code

Definition: This field contains an optional code of up to 180 characters which (if applicable) uniquely identifies the application responsible for maintaining this file at a particular site. A group of intercommunicating applications may use more than a single instance of a master file of certain type (e.g., charge master or physician master). The particular instance of the file is identified by this field. Refer to User defined table 0361 - Applications.

8.5.1.3 MFI-3 File-Level Event Code (ID) 00660

Definition: This field defines the file-level event code. Refer to HL7 table 0178 - File level event code for valid values.

HL7 Table 0178 - File level event code

Note: If the MFI-3 - File-Level Event Code is "REP" (replace file), then each MFE segment must have an MFE-1 - Record-Level Event Code of "MAD" (add record to master file).

8.5.1.4 MFI-4 Entered Date/Time (TS) 00661

Definition: This field contains the time stamp for file-level event on originating system.

8.5.1.5 MFI-5 Effective Date/Time (TS) 00662

Definition: This optional field contains the effective date/time, which can be included for file-level action specified. It is the date/time the originating system expects that the event is to have been completed on the receiving system. If this field is not present, the action date/time should default to the current date/time (when the message is received).

8.5.1.6 MFI-6 Response Level Code (ID) 00663

Definition: These codes specify the application response level defined for a given Master File Message at the MFE segment level as defined in HL7 table 0179 - Response level. Required for MFN-Master File Notification message. Specifies additional detail (beyond MSH-15 - Accept Acknowledgment Type and MSH-16 - Application Acknowledgment Type) for application-level acknowledgment paradigms for Master Files transactions. MSH-15 - Accept Acknowledgment Type and MSH-16 - Application Acknowledgment Type operate as defined in Chapter 2.

HL7 Table 0179 - Response level

The Technical Steward for the MFE segment is CQ.

HL7 Attribute Table - MFE - Master File Entry

8.5.2.1 MFE-1 Record-Level Event Code (ID) 00664

Definition: This field defines the record-level event for the master file record identified by the MFI segment and the primary key field in this segment. Refer to HL7 table 0180 - Record level event code for valid values.

HL7 Table 0180 - Record-level event code

Note: If the MFI-3 - File-level event code is "REP" (replace file), then each MFE segment must have an MFE-1 - Record-level event code of "MAD" (add record to master file).

8.5.2.2 MFE-2 MFN Control ID (ST) 00665

Definition: A number or other identifier that uniquely identifies this change to this record from the point of view of the originating system. When returned to the originating system via the MFA segment, this field allows the target system to precisely identify which change to this record is being acknowledged. It is only required if the MFI response level code requires responses at the record level (any value other than NE).

Note: Note that this segment does not contain a Set ID field. The MFE-2 - MFN Control ID implements a more general concept than the Set ID. It takes the place of the SET ID in the MFE segment.

8.5.2.3 MFE-3 Effective Date/Time (TS) 00662

Definition: An optional effective date/time can be included for the record-level action specified. It is the date/time the originating system expects that the event is to have been completed on the receiving system. If this field is not present, the effective date/time should default to the current date/time (when the message is received).

8.5.2.4 MFE-4 Primary Key Value - MFE (Varies) 00667

Definition: This field uniquely identifies the record of the master file (identified in the MFI segment) to be changed (as defined by the record-level event code). The data type of field is defined by the value of MFE-5 - Value Type, and may take on the format of any of the HL7 data types defined in HL7 table 0355 - Primary Key Value Type. The PL data type is used only on Location master transactions.

The following exception to the use of the CE data type is deprecated in v 2.3.1, and left only to satisfy backwards compatibility. When the CE data type is used, the first component of this CE data field carries an optional subcomponent, the application ID, that uniquely identifies the application responsible for creating the primary key value. The application ID subcomponent can be used to guarantee uniqueness of the primary key across multiple applications.

The repetition of the primary key permits the identification of an individual component of a complex record as the object of the record-level event code. This feature allows the Master Files protocol to be used for modifications of single components of complex records. If this field repeats, the field MFE-5 - Value Type must also repeat (with the same number of repetitions), and the data type of each repetition of MFE-4 - Primary Key Value - MFE is specified by the corresponding repetition of MFE-5 - Value Type.

8.5.2.5 MFE-5 Primary Key Value Type (ID) 01319

Definition: This field contains the HL7 data type of MFE-4 - Primary Key Value - MFE. The valid values for the data type of a primary key are listed in HL7 table 0355 - Primary key value type.

HL7 Table 0355 - Primary key value type

Note: This table contains data types for MFE-4 values present in HL7 defined master files. As HL7 adopts a new master file that contains a data type for MFE-4 not defined in Table 0355, the data type will be added to Table 0355. For locally defined master files, this table can be locally extended with other HL7 data types as defined in section 2.6.6.

8.5.3 MFA - Master File Acknowledgment Segment

The Technical Steward for the MFA segment is CQ.

The MFA segment contains the following fields as defined in HL7 Attribute Table - MFA - Master File Acknowledgment

HL7 Attribute Table - MFA - Master File Acknowledgment

8.5.3.1 MFA-1 Record-Level Event Code (ID) 00664

Definition: This field defines record-level event for the master file record identified by the MFI segment and the primary key in this segment. Refer to HL7 table 0180 - Record level event code for valid values.

Note: If the MFI-3 - File-level event code is "REP" (replace file), then each MFA segment must have an MFA-1 - Record-level event code of "MAD" (add record to master file).

8.5.3.2 MFA-2 MFN Control ID (ST) 00665

Definition: This field contains a number or other identifier that uniquely identifies this change to this record from the point of view of the originating system. This field uniquely identifies the particular record (identified by the MFE segment) being acknowledged by this MFA segment. When returned to the originating system via the MFA segment, this field allows the target system to precisely identify which change to this record is being acknowledged. It is only required if MFI-6 - Response Level Code requires responses at the record level (any value other than NE).

8.5.3.3 MFA-3 Event Completion Date/Time (TS) 00668

Definition: This field may be required or optional depending on the site specifications for the given master file, master file event, and receiving facility.

8.5.3.4 MFA-4 MFN Record Level Error Return (CE) 00669

Definition: This field contains the status of the requested update. Site-defined table, specific to each master file being updated via this transaction.

Refer to User-defined Table 0181 - MFN record-level error return for suggested values. All such tables will have at least the following two return code values:

User-defined Table 0181 - MFN record-level error return

Definition: This field uniquely identifies the record of the master file (identified in the MFI segment) for which the update status is being acknowledged (as defined by the field MFN-4 - Record Level Error Return). The data type of this field is defined by the value of MFA-6 - Value Type - MFA, and may take on the format of any of the HL7 data types defined in HL7 table 0355 - Primary Key Value Type. The PL data type is used only on location master transactions.

The following exception to the use of the CE data type is deprecated in V2.3.1, and left in for backward compatibility. When the CE data type is used, the first component of this CE data field carries an optional subcomponent, the application ID, that uniquely defines the application responsible for creating the primary key value. The application ID subcomponents can be used to guarantee uniqueness of the primary key across multiple applications.

The repetition of the primary key permits the identification of an individual component of a complex record as the object of the record-level event code. This feature allows the Master Files protocol to be used for modifications of single components of complex records. If this field repeats, the field MFA-6 - Primary Key Value Type - MFA must also repeat (with the same number of repetitions), and the data type of each repetition of MFA-5 - Primary Key Value - MFA is specified by the corresponding repetition of MFA-6 - Value Type - MFA.

8.5.3.6 MFA-6 Primary Key Value Type - MFA (ID) 01320

Definition: This field contains the HL7 data type of MFA-5 - Primary Key Value - MFA. The valid HL7 data types are listed in HL7 table 0355 - Primary key value type.

8.6 GENERIC MASTER FILE EXAMPLES

The following are examples of a generic method of updating a standard HL7 table, covering the following two cases:

1. The case with a site-defined _Z_ segment. This message type is used when standard HL7 segments are not available to carry all of the required information on the master file. This message type can also be used in the case where standard HL7 segments are available, but the transaction type is not currently defined by HL7. Refer to Section 8.4.3, MFN/MFK - Master File Notification - Site Defined (Event M14) for more information on this message type.

2. The case without a site-defined _Z_ segment. This message type is used when standard HL7 segments are available to carry all of the required information on the master file (in the case of a _simple_ master file that contains only a key and the text value of that key). Refer to Section 8.4.2, MFN/MFK - Master File Notification - General (Event M13) for more information on this message type.

These examples show two records being added to HL7 table 0006 - Religion.

Note: A site-defined _Z_ table segment (_ZL7_ in this example) can be constructed by defining two fields: a table entry field (as a CE field) and a display-sort-key field (a numeric field) as follows.

8.6.1 ZL7 Segment (Proposed Example Only)

HL7 Attribute Table _ ZL7 _ (proposed example only)

8.6.1.1 ZL7-1 Primary Key Value - ZL7 (CE)

Definition: This field contains HL7 table values for identifier and text encoded as a CE data type.

8.6.1.2 ZL7-2 Display-Sort-Key (NM)

Definition: This field is used to specify a non-alphabetic ordering for display or print versions of a standard HL7 table.

8.6.2 MFN Message With Original Acknowledgment Mode

8.6.2.0

8.6.2.1 Example message

The initiating system constructs an MFN^M14 message. In this example, the message contains site-defined "Z" segments. The following message is sent to the responding system:

MSH|^~\&|HL7REG|UH|HL7LAB|CH|200106290544||MFN^M14^MFN_Z99|MSGID001|P|2.5

MFI|HL70006^RELIGION^HL70175||UPD|||AL

MFE|MAD|6772331|200106290500|BUD^Buddhist^HL70006|CE

ZL7|BUD^Buddhist^HL70006|3

MFE|MAD|6772332|200106290500|BOT^Buddhist: Other^HL70006|CE

ZL7|BOT^Buddhist: Other^HL70006|4

The responder receives the message and performs necessary validation on the message. In this example, it determines the message just received is acceptable for processing. The following MFK^M14 message is constructed by the responder and sent to the initiating system to indicate acknowledgment of the MFN^M14 message:

MSH|^~\&|HL7LAB|CH|HL7REG|UH|200106290545||MFK^M14^MFK_M01|MSGID99001|P|2.5

MSA|AA|MSGID001

MFI|HL70006^RELIGION^HL70175||UPD|||AL

MFA|MAD|6772331|200106290545|S|BUD^Buddhist^HL70006|CE

MFA|MAD|6772332|200106290545|S|BOT^Buddhist: Other^HL70006|CE

Note that MSA-1 - Acknowledgment Code contains 'AA' to indicate the message was received and processed successfully. This value could also have been 'AE' or 'AR' to indicate the message was received but not processed successfully. MSA-2 - Message Control ID contains the value from MSH-10 - Message Control ID in the initiating MFN^M14 message (MSGID001) to link the acknowledgment response to the initiating message.

8.6.3 MFN message with enhanced Mode Application-Level Acknowledgment

8.6.3.0

8.6.3.1 Example message

The initiating system constructs an MFN^M13 message. In this example, the message does not contain site-defined "Z" segments. The following message is sent to the responding system:

MSH|^~\&|HL7REG|UH|HL7LAB|CH|200106290544||MFN^M13^MFN_M01|MSGID004|P|2.5||AL|AL

MFI|HL70006^RELIGION^HL70175||UPD|||AL

MFE|MAD|6772333|200106290500|BUD^Buddhist^HL70006|CE

MFE|MAD|6772334|200106290500|BOT^Buddhist: Other^HL70006|CE

The responder receives the message and performs necessary validation on the message. In this example, it determines the message just received is acceptable for processing. Since MSH-15 - Accept Acknowledgment of the initiating message indicates an accept acknowledgment is required ('AL'), the following ACK message is constructed by the responder and sent to the initiating system to indicate acknowledgment of the MFN^M13 message:

MSH|^~\&|HL7LAB|CH|HL7REG|UH|200106290545||ACK^M13^ACK|MSGID99004|P|2.5

MSA|CA|MSGID004

Note that MSA-1 - Acknowledgment Code contains 'CA' to indicate the message was received and committed to safe storage. This value could also have been 'CE' or 'CR' to indicate the message was received but not processed successfully. MSA-2 - Message Control ID contains the value from MSH-10 - Message Control ID in the initiating MFN^M13 message (MSGID004) to link the acknowledgment response to the initiating message.

The initiating system indicated in this example via MSH-16 - Application Acknowledgment Type that it requires an application level acknowledgment ('AL'). The responder, at some point following the sending of the above ACK message to the initiating system, will process the MFN^M13 message. Once message processing is complete, the application acknowledgment is sent from the responder to the initiating system to indicate the message was processed. The responder constructs an MFK^M13 acknowledgment message, and sends it to the initiating system:

MSH|^~\&|HL7LAB|CH|HL7REG|UH|200106290550||MFK^M13^MFK_M01|MSGID99501|P|2.5||AL|

MSA|AA|MSGID004

MFI|HL70006^RELIGION^HL70175||UPD|||AL

MFA|MAD|6772333|200106290550|S|BUD^Buddhist^HL70006|CE

MFA|MAD|6772334|200106290550|S|BOT^Buddhist: Other^HL70006|CE

Note that MSA-1 - Acknowledgment Code contains 'AA' to indicate the message was received and processed successfully. This value could also have been 'AE' or 'AR' to indicate the message was received but not processed successfully. This value applies to all MFA segments which follow. MSA-2 - Message Control ID contains the value from MSH-10 - Message Control ID in the initiating MFN^M13 message (MSGID004) to link the application acknowledgment response to the initiating message.

The initiating system receives the application acknowledgment message from the responder, and forms an ACK message to acknowledge it. The following message is sent to the responder system:

MSH|^~\&|HL7REG|UH|HL7LAB|CH|200106290551||ACK^M13^ACK|MSGID445|P|2.5

MSA|CA|MSGID99501

Note that MSA-2 - Message Control ID contains the value from MSH-10 - Message Control ID in the MFK^M13 message just received (MSGID99501), and NOT from the initiating MFN^M13 message.

8.7 STAFF AND PRACTITIONER MASTER FILES

8.7.1 MFN/MFK - Staff/Practitioner Master File Message (Event M02)

The staff identification (STF), practitioner detail (PRA), practitioner organization unit segment (ORG), professional affiliation (AFF), language detail (LAN), educational detail (EDU), and certificate detail (CER) segments can be used to transmit master files information between systems. The STF segment provides general information about personnel; the PRA, ORG, AFF, LAN, EDU, CER and NTE segments provide detailed information for a staff member.

Note: The STF and PRA segments have been moved to Chapter 15 - Personnel Management. The ORG, AFF, LAN, EDU, and CER segments are defined in Chapter 15 - Personnel Management. The NTE segment is defined in Chapter 2 - Control.

When the STF, PRA, ORG, AFF, LAN, EDU, CER and NTE segments are used in an MFN message, the abstract definition is as follows:

MFK^M02^MFK_M01	Master File Acknowledgment	Status	Chapter	DB Ref.
MSH	Message Header		2	DB
[ { SFT } ]	Software		2	DB
MSA	Acknowledgment		2	DB
[ { ERR } ]	Error		2	DB
MFI	Master File Identification		8	DB
[ { MFA } ]	Master File ACK segment		8	DB

Note: As of v2.5, the PRA and ORG segments in the MFN^M02 are repeatable. HL7 does not give semantic meaning to the first instance of either. Refer to section 2.8.2.d in Chapter 2.

When the STF, PRA, ORG, AFF, LAN, EDU, and CER segments are used in the MFR message, the part of the message represented by:

MSH|^~\&|HL7REG|UH|HL7LAB|CH|200102280700||MFN^M02^MFN_M02|MSGID002|P|2.5|||AL|NE

MFI|PRA^Practitioner Master File^HL70175||UPD|||AL

MFE|MAD|U2246|200102280700|PMF98123789182^^PLW

STF|PMF98123789182^^PLW|U2246^^^PLW~111223333^^^USSSA^SS|KILDARE^RICHARD^J^JR^DR^M.D.|P|M|19511004|A|^ICU|^MED|(206)689-1999X345CO~(206)283-3334CH(206)689-1345X789CB|214 JOHNSON ST^SUITE 200^SEATTLE^WA^98199^H~3029 24TH AVE W^^SEATTLE, WA^98198^O |19890125^UMC&University Medical Center&L01||PMF88123453334|74160.2326@COMPUSERV.COM|B

PRA|PMF98123789182^^PLW|^KILDARE FAMILY PRACTICE|ST|I|OB/GYN^STATE BOARD OF OBSTETRICS AND GYNECOLOGY^C^19790123|1234887609^UPIN~1234987^CTY^MECOSTA~223987654^TAX~1234987757^DEA~12394433879^MDD^CA|ADMIT&&ADT^MED&&L2^19941231~DISCH&&ADT^MED&&L2^19941231|

AFF|1|AMERICAN MEDICAL ASSOCIATION|123 MAIN STREET^^OUR TOWN^CA^98765^U.S.A.^M |19900101|

LAN|1|ESL^SPANISH^ISO639|1^READ^HL70403|1^EXCELLENT^HL70404|

LAN|2|ESL^SPANISH^ISO639|2^WRITE^HL70403|2^GOOD^HL70404|

LAN|3|FRE^FRENCH^ISO639|3^SPEAK^HL70403|3^FAIR^HL70404|

EDU|1|BA^BACHELOR OF ARTS^HL70360|19810901^19850601|YALE UNIVERSITY^L|U^HL70402|456 CONNECTICUT AVENUE^^NEW HAVEN^CO^87654^U.S.A.^M|

EDU|2|MD^DOCTOR OF MEDICINE^HL70360|19850901^19890601|HARVARD MEDICAL SCHOOL^L |M^HL70402|123 MASSACHUSETTS AVENUE^CAMBRIDGE^MA^76543^U.S.A.^M|

8.8 SERVICE/TEST/OBSERVATIONS MASTER FILES

8.8.1 General Approach of Service/Test/Observation Master Files

These segments define the format for the general information about the observations that a clinical or diagnostic service produces and sends to its "clients." This format can be used to send the producer_s entire service/test/observation definition or a few of the producer_s observations, such as those with procedure, technique, or interpretation changes.

In anticipation of an object-oriented organization of segments in future releases of this Standard, the attributes of observations/batteries have been grouped into six different segments:

OM1 contains the attributes that apply to all observations

OM2 applies to numerically-valued observations

OM3 applies to text or code-valued observations

OM4 applies to observations or batteries that require specimens

OM5 contains the attributes of batteries, or sets of observations or other batteries

OM6 contains the quantities (observations in a most general sense) that are calculated from one or more other observations

OM7 contains additional basic attributes that apply to the definition of most observations/services.

Thus, the full definition of a numerically-valued laboratory observation would require the transmission of OM1, OM2, and OM4.

In the following discussion, we use OMx to refer to any of the six observation-defining segments. Each instance of an OMx segment contains the information about one observation or observation battery. These OMx segments are designed to be "inclusive" and accommodate the attributes of many kinds of observations. Thus, the fact that a field is listed in a particular segment should not be construed as meaning that a producer must include information about that item in its definition transmission. Many fields will apply to some terms; others will not. One observation producer may choose to populate one set of fields; another may choose to populate a different set of fields, according to the requirements of that producer_s "client."

Most of the fields of data type TX in those segments are intended to include information typically contained in a diagnostic service_s user manual. Such fields should describe how the data is to be interpreted or used, and are not intended for computer interpretation.

Remember that the magnitude of a treatment can also be regarded as an observation and, as such, can be represented as an observation within these segments. Many examples exist. When a blood gas is transmitted, the requesting service usually transmits the amount of inspired O2 (a treatment) on requisition. (In an electronic transmission, the service would send this as an OBX segment, along with the electronic order for the test.) When blood levels are drawn, the amount and time of the last dose are routinely included as observations on the request for service. A pharmacy system could routinely send to a medical record system the average daily dose of each outpatient medication it dispenses. In such cases, the treatment amounts would be observations to the receiving system and would be transmitted as OBX segments. When received, they would be treated like any other observation. A medical record system could then create, for example, a flowchart of lab results, or lab results mixed with relevant treatments.

8.8.2 MFN/MFK - Master File Notification - Test/Observation (Event M03)

The usage of the OMx segments in the Master Files MFN and MFR messages is described in Sections 8.4.1, "MFN/MFK - Master File Notification," and 8.4.4, "MFQ/MFR - Master Files Query," above. Basically the segment groupings described below (OM1 and other segment(s)) follow the MFI and MFE segments in those messages (replacing the [...] section.

Note: MFN^M03 is retained for backward compatibility only. It is recommended that the specific master file messages which follow (MFN^M08, MFN^M09, MFN^M10, MFN^M11, and MFN^M12) be used as they apply to new implementations.

Other segment(s) represents segments that follows the OM1 segment. The available segment groups are described below in the following messages: MFN^M08, MFN^M09, MFN^M10, MFN^M11, and MFN^M12.

Note: The MFK message is used for an application acknowledgment in either the original or enhanced acknowledgment modes.

8.8.3 MFN/MFK - Master File Notification - Test/Observation (Numeric) (Event M08)

Note: The MFK message is used for an application acknowledgment in either the original or enhanced acknowledgment modes.

Note: MFI-1 - Master File Identifier = OMA for numeric observations.

Note: A service/test/observation definition may have both an OM2 (numeric) and OM3 (categorical) segment included in case the value may be either numeric and/or categorical.

8.8.4 MFN/MFK - Master File Notification - Test/Observation (Categorical) (Event M09)

MFK^M09^MFK_M01	Master File Application Acknowledgment	Status	Chapter	DB Ref.
MSH	Message Header		2	DB
[ { SFT } ]	Software		2	DB
MSA	Acknowledgment		2	DB
[ { ERR } ]	Error		2	DB
MFI	Master File Identification		8	DB
[ { MFA } ]	Master File ACK segment		8	DB

Note: The MFK message is used for an application acknowledgment in either the original or enhanced acknowledgment modes.

Note: MFI-1 - Master File Identifier = OMB for categorical observations.

8.8.5 MFN/MFK - Master File Notification - Test/Observation Batteries (Event M10)

MFK^M10^MFK_M01	Master File Application Acknowledgment	Status	Chapter	DB Ref.
MSH	Message Header		2	DB
[ { SFT } ]	Software		2	DB
MSA	Acknowledgment		2	DB
[ { ERR } ]	Error		2	DB
MFI	Master File Identification		8	DB
[ { MFA } ]	Master File ACK segment		8	DB

Note: The MFK message is used for an application acknowledgment in either the original or enhanced acknowledgment modes.

Note: MFI-1 - Master File Identifier = OMC for observation batteries.

8.8.6 MFN/MFK - Master File Notification - Test/Calculated Observations (Event M11)

MFK^M11^MFK_M01	Master File Application Acknowledgment	Status	Chapter	DB Ref.
MSH	Message Header		2	DB
[ { SFT } ]	Software		2	DB
MSA	Acknowledgment		2	DB
[ { ERR } ]	Error		2	DB
MFI	Master File Identification		8	DB
[ { MFA } ]	Master File ACK segment		8	DB

Note: The MFK message is used for an application acknowledgment in either the original or enhanced acknowledgment modes.

Note: MFI-1 - Master File Identifier = OMD for calculated observations.

8.8.7 MFN/MFK - Master File Notification - Additional Basic Observation/Service Attributes (Event M12)

MFK^M12^MFK_M01	Master File Application Acknowledgment	Status	Chapter	DB Ref.
MSH	Message Header		2	DB
[ { SFT } ]	Software		2	DB
MSA	Acknowledgment		2	DB
[ { ERR } ]	Error		2	DB
MFI	Master File Identification		8	DB
[ { MFA } ]	Master File ACK segment		8	DB

Note:

Note: The MFK message is used for an application acknowledgment in either the original or enhanced acknowledgment modes.

Note: MFI-1 - Master File Identifier = OME for additional basic observation/service attributes.

8.8.8 OM1 - General Segment (Fields That Apply to Most Observations)

The Technical Steward for the OM1 segment is ORDERS.

The OM1 segment contains the attributes that apply to the definition of most observations. This segment also contains the field attributes that specify what additional segments might also be defined for this observation.

HL7 Attribute Table - OM1 - General Segment

8.8.8.1 OM1-1 Sequence Number - Test/Observation Master File (NM) 00586

Definition: This field contains the first OM1 segment in a message and is described as 1, the second as 2, and so on.

8.8.8.2 OM1-2 Producer's Service/Test/Observation ID (CE) 00587

Definition: This field contains the producer_s usual or preferred identification of the test or observation. Only three components should be included: <ID code>^<service text name/description>^<source list of code>. All components should be non-null. The source list may be any of those included in ASTM Tables 3 and 5, or a local code.

8.8.8.3 OM1-3 Permitted Data Types (ID) 00588

Definition: This field contains the allowed data type(s) for this observation. The codes are the same as those listed for OBX (a given observation may, under different circumstances, take on different data types). Indeed, under limited circumstances, an observation can consist of one or more fragments of different data types. When an observation may have more than one data type, e.g., coded (CE) and numeric (NM) the allowable data types should be separated by repeat delimiters. Refer to HL7 table 0125 - Value type for valid values.

8.8.8.4 OM1-4 Specimen Required (ID) 00589

Definition: This field contains a flag indicating whether or not at least one specimen is required for the service/test/observation. Refer to HL7 table 0136 - Yes/no indicator as defined in Chapter 2.

Y one or more specimens are required to obtain this observation

N a specimen is not required

When a specimen is required, segment OM4 will usually be included (one per specimen is required).

8.8.8.5 OM1-5 Producer ID (CE) 00590

Definition: This field uniquely identifies the service producing the observation described in this segment. Three components should be included: an identifying code, the name of the producer, and the identity of the coding system (e.g., 323-5678^Acme Special Lab^MC). The identity of the coding system will usually be MC (Medicare provider number or HIBCC site codes) in the United States. Each country may want to specify its preferred coding system and define a coding system ID to identify it.

Remember that the magnitude of a treatment or the setting on a machine, such as a ventilator, can be regarded as an observation. Thus, pharmacy, respiratory care, and nursing may be producers of such observations.

8.8.8.6 OM1-6 Observation Description (TX) 00591

Definition: This field contains a text description of this observation.

8.8.8.7 OM1-7 Other Service/Test/Observation IDs for the Observation (CE) 00592

Definition: This field contains all alias codes/identifiers for this observation. If more than one alias code needs to be specified, multiple three-component, CE-format entries (<code 1>^<name 1>^<code system 1>) may be given, separated by repeat delimiters. An observation may have as many names/codes as are applicable (e.g., ICD9, ACR-NEMA, SNOMED, and READ). We encourage the inclusion of as many different codes as may apply to assist cross-system mapping of terminology. All components of each triplet should be non-null (that is, names and coding system IDs within the CE data type are required in addition to codes). The source list may be any of those included in ASTM Tables 3 and 5.

Because the size (dose) of a treatment can also be an observation, codes that identify treatments (e.g., NDC, ICCS) may also be included in this field.

Note: In this field, the names within the CE data type are required.

8.8.8.8 OM1-8 Other Names (recognized by the producer for the observation) (ST) 00593

Definition: This field contains any test aliases or synonyms for the name in the context of the ordering service. These are alternative names, not associated with a particular coding system, by which the battery, test, or observation (e.g., measurement, test, diagnostic study, treatment, etc.) is known to users of the system. Multiple names in this list are separated by repeat delimiters.

8.8.8.9 OM1-9 Preferred Report Name for the Observation (ST) 00594

Definition: This field contains the preferred name for reporting the observation or battery. The name can contain up to 30 characters (including blanks). It is the preferred name for columnar reports that require a maximum name size.

8.8.8.10 OM1-10 Preferred Short Name or Mnemonic for the Observation (ST) 00595

Definition: This field contains the name that can be used in space-limited reports (e.g., specimen labels) to identify the observation for the convenience of human readers. The name can contain up to eight characters.

8.8.8.11 OM1-11 Preferred Long Name for the Observation (ST) 00596

Definition: This field contains the fully-specified name for the observation or battery. It may include the full (unabbreviated) multiple-word names and contain up to 200 characters. It should be as scientifically precise as possible.

8.8.8.12 OM1-12 Orderability (ID) 00597

Definition: This field indicates whether or not a service/test/observation is an orderable code. Refer to HL7 table 0136 - Yes/no indicator for valid values.

Y the service/test/observation is an orderable code

N the service/test/observation is not orderable

For example, blood differential count is usually an orderable "test," MCV, contained within the differential count, is usually not independently orderable.

8.8.8.13 OM1-13 Identity of Instrument Used to Perform This Study (CE) 00598

Definition: When applicable, this field identifies the instrument or device that is used to generate this observation or battery. Examples are the automated instrument in the laboratory, the imaging device and model number in radiology, and the automatic blood pressure machine on the ward. The instrument 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. If more than one kind of instrument is used, all of them can be listed, separated by repeat delimiters.

8.8.8.14 OM1-14 Coded Representation of Method (CE) 00599

Definition: This field contains the method(s) used to produce the observation and should be recorded in a computer-understandable (coded) form here. This field should report the same method(s) reported in narrative in the following field. More than one method may be listed, but only if they produce results that are clinically indistinguishable. Multiple methods must be separated by repeat delimiters.

8.8.8.15 OM1-15 Portable Device Indicator (ID) 00600

Definition: This field indicates whether or not a portable device may be used for the service/test/observation. Refer to HL7 table 0136 - Yes/no indicator for valid values.

Y the observation can be obtained with a portable device brought to the patient

N the patient or specimen must be transported to the device

8.8.8.16 OM1-16 Observation Producing Department/Section (CE) 00601

Definition: This field permits the sorting of observation orders and values by the providing service_s department/section. It provides "source oriented" reporting when required. The codes for this field should be taken from ASTM Table 15 (Diagnostic Service Codes). Free text may be used instead of these codes, but in that case, they should be recorded as the second "component" of the field to distinguish them from the standard codes. Multiple codes in this field are separated by repeat delimiters.

8.8.8.17 OM1-17 Telephone Number of Section (XTN) 00602

Definition: This field contains the telephone number for calling responsible parties in this section to ask results or advice about the use of this test.

8.8.8.18 OM1-18 Nature of Service/Test/Observation (IS) 00603

Definition: This field indicates whether the definition entry identifies a test battery, an entire functional procedure or study, a single test value (observation), multiple test batteries or functional procedures as an orderable unit (profile), or a single test value (observation) calculated from other independent observations. Refer to User-defined Table 0174 - Nature of service/test/observation for suggested values.

User-defined Table 0174 - Nature of Service/Test/Observation

Codes P, F, and S identify sets (batteries) and should be associated with an OM5 segment that defines the list of elements. The definitions for the contained elements would have to be sent in other independent OMx segments, one for each contained element. In the ASTM context, most text reports - such as discharge summaries, admission H&Ps, and chest X-ray reports - are considered as sets, in which each section of the report (e.g., description, impression, and recommendation of an X-ray report) is considered a separate observation.

Code A identifies a single direct observation and would usually be associated with an OM2 and/or OM3 segments.

Code C identifies a derived quantity and would usually be associated with an OM6 segment.

All of these codes can be associated with one or more OM4 (specimen) segments.

8.8.8.19 OM1-19 Report Subheader (CE) 00604

Definition: This field contains an optional string that defines the preferred header under which this observation should be listed on a standard display. For example, if the test is hemoglobin, this string might be "Complete blood count." It is represented as a coded data type so that a battery can be a header. Only the description part of the string may be included in case the subheader does not have an associated code. When a series of observations is displayed according to the sort order given below, the subheader that groups those observations is presented whenever the subheader changes.

8.8.8.20 OM1-20 Report Display Order (ST) 00605

Definition: This field contains an optional string that defines the sort order in which this observation is presented in a standard report or display that contains the many observations.

8.8.8.21 OM1-21 Date/Time Stamp For Any Change In Definition For The Observation (TS) 00606

Definition: This field contains the date and time that the last of any field change was made and in the host_s record corresponding to the OM1 segment.

8.8.8.22 OM1-22 Effective Date/Time of Change (TS) 00607

Definition: This field contains the date and time of the last change in the test procedure that would make previous results incompatible with new results, e.g., the last time that normal reference range or units changed for a numeric test/observation.

We strongly suggest that observation producers never use the same observation ID when the measurement procedures change in such a way that results produced under the new procedure are clinically different from those produced with the old procedure. Rather, the producer should try to adjust the new procedure so that its values are clinically indistinguishable from the old. Failing that, one should create a new observation ID for the observation produced under the new procedure.

In the rare circumstances when a procedure change occurs and neither of the above two options is viable, this field shall be used to transmit the effective date/time of the new procedure. The receiving system shall assume that any values that come across under this observation ID are under the new procedure after this date and take appropriate steps to distinguish the old from the new observations.

This number is included to provide a means of communicating with the observation producing service when they have questions about particular observations or results.

8.8.8.23 OM1-23 Typical Turn-Around Time (NM) 00608

Definition: This field contains the typical processing time for single test/observation. This field indicates the time from the delivery of a specimen or transport of a patient to a diagnostic service and the completion of the study. It includes the usual waiting time. The units are measured in minutes.

8.8.8.24 OM1-24 Processing Time (NM) 00609

Definition: This field contains the usual length of time (in minutes) between the start of a test process and its completion.

8.8.8.25 OM1-25 Processing Priority (ID) 00610

Definition: This field contains one or more available priorities for performing the observation or test. This is the priority that can be placed in TQ1-9 - Priority. Multiple priorities may be given, separated by repeat delimiters. For example, S~A~R~P~T indicates that the test may be ordered using codes S, A, R, P, or T. Refer to HL7 table 0168 - Processing priority for valid values.

HL7 Table 0168 - Processing priority

For tests requiring a specimen, the priority for obtaining the specimen is included in OM4-13 - Specimen Priorities.

8.8.8.26 OM1-26 Reporting Priority (ID) 00611

Definition: This field contains the available priorities reporting the test results when the user is asked to specify the reporting priority independent of the processing priority. Refer to HL7 Table 0169 - Reporting priority for valid values.

HL7 Table 0169 - Reporting priority

Definition: This field contains the identification(s) of the outside service(s) that produce(s) the observation. The format of this CE field uses the producer ID (as defined in OM1-5 - Producer ID) and the name of the service separated by component delimiters. An example is _|39221^ACME lab^MC|... If multiple services are used, they should be separated by repeat delimiter(s).

8.8.8.28 OM1-28 Address of Outside Site(s) (XAD) 00613

Definition: This field contains the address of the outside services listed in OM1-28 - Address of Outside Site(s) where observation may be performed. If multiple services are recorded in that field, their addresses should be separated by repeat delimiters, and the addresses should appear in the same order in which the services appear in the preceding field.

8.8.8.29 OM1-29 Phone Number of Outside Site (XTN) 00614

Definition: This field contains the telephone number of the outside site.

8.8.8.30 OM1-30 Confidentiality Code (CWE) 00615

Definition: This field contains the degree to which special confidentiality protection should be applied to the observation. For example, a tighter control may be applied to an HIV test than to a CBC. Refer to User-defined Table 0177 - Confidentiality code for suggested values.

User-defined Table 0177 - Confidentiality code

Definition: This field contains the list of variables that the diagnostic service needs to interpret the results of an ordered study. The observations specified here should be sent to the diagnostic service as OBX segments along with the order (OBR) segment.

Example for cervical pap smear:

...|2000.32^date last menstrual period^AS4~2000.33^menstrual state^AS4|...

Example for arterial blood gas:

...|94700^inspired 02^AS4|...

These examples use AS4 codes in code/text format to identify the variables. Separate multiple items by repeat delimiters.

8.8.8.32 OM1-32 Interpretation of Observations (TX) 00617

Definition: This field contains the clinical information about interpreting test results. Examples are the conditions (drugs) that may cause false abnormals, and the information about the sensitivity and specificity of the test for diagnoses.

8.8.8.33 OM1-33 Contraindications to Observations (CE) 00618

Definition: This field contains the diagnosis or problem for which the test is a contraindication or of possible danger (e.g., pacemaker, pregnancy, diabetes). For example, if the test identified in OM1 was an intravenous pyelogram, this field would include warnings about the use of contrast media in diabetes. The contraindication diagnoses should be separated by repeat delimiters.

Most contraindication rules will be transmitted as free text. In such cases, the contents serve only as information for human reading. However, an alternative for machine readable contraindication rules also exists. The rule may be defined formally in the Arden Syntax (ASTM 1460-1992) which has syntax for defining algebraic and transcendental equations, as well as temporal and logical selection criteria based on patient information stored in the computer record. Reflex rules that are written in Arden Syntax should begin and end with a double semi-colon (;;), the Arden slot delimiter.

8.8.8.34 OM1-34 Reflex Tests/Observations (CE) 00619

Definition: This field contains the test names as type CE (i.e., <code>^<text name>^<coding system>) that may be ordered automatically by the diagnostic service, depending on the results obtained from the ordered battery. A screening CBC might trigger a reticulocyte count if the Hgb is less than 12. Multiple reflex tests are separated by repeat delimiters.

8.8.8.35 OM1-35 Rules that Trigger Reflex Testing (TX) 00620

Definition: This field contains the rules that trigger the reflex tests listed above. If multiple reflex tests are listed in OM1-34 - Reflex Text/Observations separated by repeat delimiters, a set of corresponding rules will be included in this section. The first rule will apply to the first test, the second to the second test, and so on.

Most reflex rules will usually be transmitted as free text. In such cases, the contents serve only as information for human reading. However, an alternative for machine readable rules also exists. The rule may be defined formally in the Arden Syntax (ASTM 1460-1992) which has syntax for defining algebraic and transcendental equations, as well as temporal and logical selection criteria based on patient information stored in the computer record. Reflex rules that are written in Arden Syntax should begin and end with a double semi-colon (;;), the Arden slot delimiter.

8.8.8.36 OM1-36 Fixed Canned Message (CE) 00621

Definition: This field contains the codes and a fixed text message that is always associated with an abbreviation. The field may include multiple messages separated by repeat delimiters.

Most rules about patient testing will be transmitted as free text. In such cases, the contents serve only as information for human reading. However, an alternative for machine readable rules also exists. The rule may be defined formally in the Arden Syntax (ASTM 1460-1992) which has syntax for defining algebraic and transcendental equations, as well as temporal and logical selection criteria based on patient information stored in the computer record. Rules about patient preparation are written in Arden Syntax should begin and end with a double semi-colon (;;), the Arden slot delimiter.

8.8.8.37 OM1-37 Patient Preparation (TX) 00622

Definition: This field contains the tests or observations that require special patient preparation, diet, or medications. For GI contrast studies, this field would contain the pretest diet, e.g., low residue for two days, NPO before study, and the preferred purgatives. Each separate med, diet, or preparation should be delimited by a repeat delimiter. Separate each requirement by a repeat delimiter. Example for a sigmoidectomy:

...|clear liquid diet full day before procedure~take 8 oz mag citrate 6pm day before procedure~take 2 ducat tabs (5m) at 4pm day before procedure~NPO past midnight.|...

8.8.8.38 OM1-38 Procedure Medication (CE) 00623

Definition: This field contains the treatments that may be needed as part of the procedure. Examples are radioactive iodine for a thyroid screen, and methacholine for a methacholine spirometry challenge. This field should be identified as a CE data type.

8.8.8.39 OM1-39 Factors That May Affect the Observation (TX) 00624

Definition: This field contains the text description of the foods, diagnoses, drugs, or other conditions that may influence the interpretation of the observation. Information about the direction of the effect, and any recommendation about altering the diet, conditions, or drug before initiating the test observation.

Most rules about factors that effect the test interpretation will be transmitted as free text. In such cases, the contents serve only as information for human reading. However, an alternative for machine readable rules also exists. The rule may be defined formally in the Arden Syntax (ASTM 1460-1992) which has syntax for defining algebraic and transcendental equations, as well as temporal and logical selection criteria based on patient information stored in the computer record. Rules about patient preparation are written in Arden Syntax and should begin and end with a double semi-colon (;;), the Arden slot delimiter.

8.8.8.40 OM1-40 Service/Test/Observation Performance Schedule (ST) 00625

Definition: This field contains the diagnostic studies/tests that are performed only at certain times during the course of a work day or work week. This field indicates the maximum interval between successive test performances (the test may actually be performed more frequently). The format given in Chapter 4, Section 4.3.2.1, "Repeat Pattern," should be used. If necessary, multiple codes may be given, separated by repeat delimiters. The use of multiple codes indicates that the test is performed at multiple concurrent intervals. For example, Q6H indicates that the test is performed at least once every 6 hours around the clock. QJ1 indicates that the test is performed at least every week on Mondays. QAM~QPM indicates that the test is performed at least once every morning and every evening. QJ1~QJ3~QJ5 indicates that the test is performed at least every week on Mondays, Wednesdays, and Fridays. C indicates that the test is performed continuously, 7 days per week.

8.8.8.41 OM1-41 Description of Test Methods (TX) 00626

Definition: This field contains the text description of the methods used to perform the text and generate the observations. Bibliographic citations may be included.

8.8.8.42 OM1-42 Kind of Quantity Observed (CE) 00937

Definitions: This optional attribute describes the underlying kind of property represented by this observation. This attribute distinguishes concentrations from total amounts, molar concentrations from mass concentrations, partial pressures from colors, and so forth. These are discussed more fully in the LOINC Users_ Manual. They are derived from the approach described in 1995 edition of the IUPAC Silver Book. These distinctions are used in IUPAC and LOINC standard codes. Defined categories are listed in HL7 table 0254 - Kind of quantity.

The distinctions of true quantities in this table are based primarily on dimensional analyses. The table contains a number of "families," those related to simple counts (number, number concentration, etc.), to mass (mass, mass concentration, etc.), to enzyme activity (catalytic content, catalytic concentration, etc.), and molar or equivalents (substance content, substance concentration).

By this classification, a glucose (in the US) would be classed as a mass concentration. A sodium would be classed as a substance concentration. Within the family, a total amount should be described as the unadorned variant; e.g., the property of measure for a patient_s weight would be mass, not mass content. Most chemical measures produce concentrations, as exemplified by sodium and glucose. However, a 24-hour urine protein is not a mass concentration, but a mass rate (mass per unit time). The content variants (e.g., mass content, substance content) are used to reflect an amount per mass (usually) of tissue.

This attribute would be valued in a master file only if the service sending the master file classified observations by their principle of measurement.

HL7 Table 0254 - Kind of quantity

Definition: This optional attribute allows master files to classify observations as measuring the patient_s state at a point in time (e.g., spot urines, random urines, serum potassium), or averaged over a interval of time (e.g., concentration, total amount, or clearance over a 24-hour collection). Interval measures most often apply to urine and stool specimens (e.g., 24-hour urines, 3-day stool fats). They also apply to clinical measurements such as urine outputs, which are reported as shift totals and 24-hour totals, and event counts on physiologic monitors such as the number of PVCs on a 24-hour Holter monitor.

This field would only be valued in a transaction if the service sending this master file message classified its observation by point versus time interval. This field is not used to record the time collection interval for a particular sample. It is used to specify a characteristic of an observation which has a defined normal range and to distinguish observations of the same kind but observed over varying periods of time. A spot urine sodium would have PT stored in this field. A 24-hour urine sodium and a 24-hour Holter monitor would have 24H stored here. This attribute would only be valued if the filling service classified its observations by timing. Refer to User-defined Table 0255 - Duration categories for suggested values.

User-defined Table 0255 - Duration categories

Definition: This optional attribute provides information for classifying observations by the challenge component of the test, if a challenge does speciate the observation. For example, distinguishing tests that have a challenge component in database. There co-ascribes the physiologic or drug challenge that is intrinsic to the measurement. To identify, for example, tests that include a glucose challenge.

To construct this text string, use the following template. (Note: This field is not constructed of formally defined components; it is a free text field. Component delimiters are not used and it is not necessary to supply placeholders if some "components" are not used.)

The time delay follows the syntax: n<S|M|H|D|W> where n is a number (possibly a decimal); S denotes seconds; M denotes minutes; H denotes hours; D denotes days; and W denotes weeks. The time delay can be preceded by a _greater than_ (>) sign, e.g. >4H.

HL7 Table 0256 - Time delay post challenge lists possible values for time delay.

Examples

PRE 100 GM GLUCOSE PO

PRE 100 GM GLUCOSE PO

30M POST 100 GM GLUCOSE PO

2H POST 100 GM GLUCOSE PO

TROUGH

For drug peak and trough measures the nature of the substance challenged is the same as the analyte name, and need not be included.

We denote the route of the challenge via abbreviations for medication routes (see Chapter 4, Section 4.14.2.1, "Route," HL7 table 0162 - Route of administration). An oral route of administration would be denoted by "PO," an intravenous route by "IV."

Details of the drug dose, time the dose was given, route of administration, etc., would be noted in separate OBX, and would have corresponding master observation definitions stored in the observation master file map to different records stored in the master file segments contained in the drug level message.

HL7 Table 0256 - Time delay post challenge

The nature of a physiologic (non-drug) challenge may also be specified, using the terms in HL7 Table 0257 - Nature of challenge.

HL7 Table 0257 - Nature of challenge

Definition: This optional attribute provides a mechanism for classifying observations according to the subject, in relation to the patient whose results might be stored with as "patient" data. It is standard practice, for example, to report values for controls, donors, and blood product units as well as the patient_s own values, and store them in the patient_s record. (This may not be the best way to model such information, but it is the way it is usually reported.) This should be valued when two values (e.g., one for patient and one for a blood product unit) could otherwise be confused.

The default value is "Patient," and if not specified, this value is assumed. The persons sub-component can refer to HL7 Table 0258 - Relationship modifier for valid values.

HL7 Table 0258 - Relationship modifier

Definition: This optional attribute formally indicates the site of the observation (to make it easy for a system to find all tests related to one anatomic site). It can be used to classify the observation by target site of the examination. For example, "heart" might be recorded as the target of the electrocardiogram, cardiac echo, and thallium exercise test. This attribute would be applicable to most imaging and electro-physiologic examinations. The SNOMED topology axis is an example of a coding system for anatomic sites. User-defined tables may also apply here.

8.8.8.47 OM1-47 Modality of Imaging Measurement (CE) 00942

Definition: This optional attribute describes the modality used to classify the observations, e.g., radiograph, ultrasound, CT scan, NMR, etc. This attribute is especially important for imaging studies. Refer to User-defined Table 0259 - Modality for suggested values; they are adopted from DICOM C.7.3.1.1.1 Modality. If these are used, the code source ID would be DCM.

User-defined Table 0259 - Modality

The Technical Steward for the OM2 segment is ORDERS.

This segment contains the attributes of observations with continuous values (including those with data types of numeric, date, or time stamp). It can be applied to observation batteries of type A and C (see OM1-18 - Nature of Service/Test/Observation).

HL7 Attribute Table - OM2 - Numeric Observation

8.8.9.1 OM2-1 Sequence Number - Test/Observation Master File (NM) 00586

Definition: This field contains the same value as the sequence number of the associated OM1 segment.

8.8.9.2 OM2-2 Units of Measure (CE) 00627

Definition: This field contains the single tests/observations (those with a nature code of A or C, as described in OM1-18 - Nature of Service/Test/Observation) that have numeric values. This field contains their customary units of measure.

8.8.9.3 OM2-3 Range of Decimal Precision (NM) 00628

Definition: This field contains the numerically valued single observations (code A or C as described in OM1-18 - Nature of Service/Test/Observation), specifies the total length in characters of the field needed to display the observation, and the number of digits displayed to the right of the decimal point. This is coded as a single number in the format <length>.<decimal-digits>. For example, a value of 6.2 implies 6 characters total (including the sign and decimal point) with 2 digits after the decimal point. For integer values, the period and <decimal-digits> portion may be omitted (that is, 5.0 and 5 are equivalent). More than one such mask may be transmitted (separated by repeat delimiters) when it is necessary to define multiple display formats that are possible.

8.8.9.4 OM2-4 Corresponding SI Units of Measure (CE) 00629

Definition: This field contains the single tests/observations - the corresponding SI units of measure in the format, when these differ from the customary units of measure given in the previous field.

8.8.9.5 OM2-5 SI Conversion Factor (TX) 00630

Definition: This field contains the continuous, numerically valued tests/observations, with a nature code of A or C (see OM1-18 - Nature of Service/Test/Observation). This is a factor for converting the customary units to SI units.

In the case that the observation units are not SI units, this field provides the formula needed to convert from the reported units to SI units, this shall include the equation needed to convert from the reporting to the SI units.

In the case that the relation is simply multiplicative, this field shall include only the conversion factor. For example., if (results SI units) = c * (results reporting units),then only c would be stored in this field. In the case of any other functional relationship, the entire equation would be stored as a test.

8.8.9.6 OM2-6 Reference (Normal) Range For Ordinal And Continuous Observations (RFR) 00631

Definition: This field contains the reference (normal) ranges for "numeric" observations/tests with a nature code of A or C (see OM1-18 - Nature of Service/Test/Observation). It can identify different reference (normal) ranges for different categories of patients according to age, sex, race, and other conditions.

In the first component of this field (Normal Range (NR)), the units are assumed to be identical to the reporting units given in OM2-2 - Units of Measure.

When two different methods result in two different reference ranges, two different observations and corresponding OMx segments should be defined.

8.8.9.7 OM2-7 Critical Range for Ordinal and Continuous Observations (RFR) 00632

Definition: This field applies only to single tests/observations (i.e., a nature code of A or C, as described in OM1-18 - Nature of Service/Test/Observation) with numeric results. When a critical range is defined for such observations, it should be recorded here in the same format as the normal range (see OM2-6 - Reference (Normal) Range - Ordinal and Continuous Observations).

Note: This field is not backward compatible from v2.5. Prior to v2.5, the narrative conflicted with the component model. There was an ARB decision to bring the component model into conformity with the narrative.

For versions prior to v2.5, the expected format would utilize the component separator (|10^20|); however for v2.5 the format will utilize the sub-component separator (|10&20|).

8.8.9.8 OM2-8 Absolute Range for Ordinal and Continuous Observations (RFR) 00633

Definition: This field applies only to single tests/observations with a nature code of A or C (see OM1-18 - Nature of Service/Test/Observation). It defines the range of possible results. Results outside this range are not possible. The field should be recorded in the same format as the normal and critical ranges.

8.8.9.9 OM2-9 Delta Check Criteria (DLT) 00634

Definition: This field applies to numeric tests/observations with a nature code of A or C (see OM1-18 - Nature of Service/Test/Observation). The field describes the information that controls delta check warnings and includes four components.

1. The range to which the following applies: <low & high>. All the ranges are defined in terms of the customary reporting units given in OM2-2 - Units of Measure. If no value range is given, the check applies to all values.

2. The numeric threshold of the change that is detected, e.g., 10.

3. Whether the change is computed as a percent change or an absolute change. This component can have two possible values:

% indicates a percent change a absolute change

1. The length of time that the service retains a value for computing delta checks. This is recorded in number of days.

More than one delta check rule can apply. 13&16^10^%^100~16.1&20^2^a^100 implies that the delta check will trigger on a 10% change when the value of the observation is between 13 and 16. The check will trigger on an absolute change of 2 when the value is between 16.1 and 20. In both cases, the system will keep the last result for 100 days. In this example, beyond 100 days, the computer will not compute a delta check because it will not have a comparison value.

8.8.9.10 OM2-10 Minimum Meaningful Increments (NM) 00635

Definition: This field contains the numerically valued single observations (a nature code of A or C, as described in OM1-18 - Nature of Service/Test/Observation) and specifies the smallest meaningful difference between reported values (the effective resolution of the measuring instrument or technique for continuous data, or the smallest discrete interval that can occur for discrete data).

8.8.10 OM3 - Categorical Service/Test/Observation Segment

The Technical Steward for the OM3 segment is ORDERS.

This segment applies to free text and other non-numeric data types.

HL7 Attribute Table - OM3 - Categorical Service/Test/Observation

8.8.10.1 OM3-1 Sequence Number - Test/Observation Master File (NM) 00586

Definition: This field contains the same value as the sequence number of the associated OM1 segment.

8.8.10.2 OM3-2 Preferred Coding System (CE) 00636

Definition: This field contains the observations whose categorical responses are taken from a specified table of codes (e.g., CE data types). Record the preferred coding system for this observation (e.g., ICD9, SNOMED III). Take the codes from ASTM Table 3 or 5, or specify a local code.

8.8.10.3 OM3-3 Valid Coded "Answers" (CE) 00637

Definition: This field contains a list of valid coded answers. In the case that the list of coded answers is easily enumerated, list the valid coded answers for this observation here using the preferred coding system given in OM3-2 - Preferred Coding System. If, for example, the given observation was VDRL, the valid answers might be non-reactive, 86^ intermediate, and 87^ reactive.

8.8.10.4 OM3-4 Normal Text/Codes for Categorical Observations (CE) 00638

Definition: Certain observations/tests with a nature code of A or C (see OM1-18 - Nature of Service/Test/Observation) have text (alpha) results (e.g., reactive, nonreactive). Alpha normals for those tests should be entered in this field (e.g., "nonreactive").

The format of this field is:

The first component is a code taken from a standard code source list. The second component is the text associated with the code. The third component is the identification of the code table source. When only a text description of a possible answer is available, it is recorded as ^<text>.

Care should be taken to transmit only those results that are considered normal for that test. A drug screen may have possible results of "negative" and "positive." However, only a result of "negative" is considered to be normal. When an observation has more than one "normal" result, multiple values in this field should be separated with a repeat delimiter.

8.8.10.5 OM3-5 Abnormal Text/Codes for Categorical Observations (CE) 00639

Definition: This field contains the list of the text answers that are abnormal for the test.

Note: Backward compatibility note - As of v2.5 this field is allowed to repeat. When used for versions prior to v2.5, extra repetitions sent will be lost.

8.8.10.6 OM3-6 Critical Text/Codes for Categorical Observations (CE) 00640

Definition: This field contains the list of coded results that are critically abnormal for this observation.

Note: Backward compatibility note - As of v2.5 this field is allowed to repeat. When used for versions prior to v2.5, extra repetitions sent will be lost.

8.8.10.7 OM3-7 Value Type (ID) 00570

Definition: This field contains the allowed data type for a single categorical observation (code A or C in OM1-18 - Nature of Observation). Refer to HL7 table 0125 - Value type for valid values.

8.8.11 OM4 - Observations That Require Specimens Segment

The Technical Steward for the OM4 segment is ORDERS.

This segment applies to observations/batteries that require a specimen for their performance. When an observation or battery requires multiple specimens for their performance (e.g., creatinine clearance requires a 24-hour urine specimen and a serum specimen), multiple segments may be included, one for each specimen type.

HL7 Attribute Table - OM4 - Observations that Require Specimens

8.8.11.1 OM4-1 Sequence Number - Test/Observation Master File (NM) 00586

Definition: This field contains the same value as the sequence number of the associated OM1 segment.

8.8.11.2 OM4-2 Derived Specimen (ID) 00642

Definition: This field contains the codes that identify the parents and children for diagnostic studies -- especially in microbiology -- where the initial specimen (e.g., blood) is processed to produce results (e.g., the identity of the bacteria grown out of the culture). The process also produces new "specimens" (e.g., pure culture of staphylococcus, and E. coli), and these are studied by a second order process (bacterial sensitivities). The parents (e.g., blood culture) and children (e.g., penicillin MIC) are identified in such cases. Refer to HL7 Table 0170 - Derived specimen for valid values:

HL7 Table 0170 - Derived specimen

Definition: This field contains the physical appearance, including color of tube tops, shape, and material composition (e.g., red-top glass tube). Note that the color is not necessarily a unique identifier of the additive and/or use of the tube. This is especially true for black and some blue tube tops, as can be seen above. Color is included here for user convenience.

8.8.11.4 OM4-4 Container Volume (NM) 00644

Definition: This field indicates the capacity of the container.

8.8.11.5 OM4-5 Container Units (CE) 00645

Definition: This field contains the units of measure of the container volume. If the units are ISO+ units, they should be recorded as single case abbreviations. If the units are ANS+ or L (local), the units and the source code table must be recorded, except that in this case, component delimiters should be replaced by subcomponent delimiters. For example, 1 indicates liters, whereas pt&&ANS+ indicates pints (ANSI units). The default unit is milliliters (ml), which should be assumed if no units are reported.

8.8.11.6 OM4-6 Specimen (CE) 00646

Definition: This field reports the specimen as one of the specimen codes described in ASTM Table 14 of 1238-91. If multiple kinds of specimen are associated with this observation (as in the case for a creatinine clearance), multiple segments may be included, one for each specimen type.

8.8.11.7 OM4-7 Additive (CWE) 00647

Definition: This field contains the codes that should be those provided by NCCLS. Refer to HL7 table 0371 - Additive/Preservative for valid values. The table_s values are taken from NCCLS AUTO4. The value set can be extended with user specific values.

This table was not specified in previous versions and thus sites may choose to use other site-specific tables.

8.8.11.8 OM4-8 Preparation (TX) 00648

Definition: This field contains the special processing that should be applied to the container, e.g., add acidifying tablets before sending.

8.8.11.9 OM4-9 Special Handling Requirements (TX) 00649

Definition: This field contains the special handling requirements here (e.g., ice specimen, deliver within two hours of obtaining).

8.8.11.10 OM4-10 Normal Collection Volume (CQ) 00650

Definition: This field contains the normal specimen volume required by the lab. This is the amount used by the normal methods and provides enough specimens to repeat the procedure at least once if needed. The default unit is milliliters (ml).

8.8.11.11 OM4-11 Minimum Collection Volume (CQ) 00651

Definition: This field contains the amount of specimen needed by the most specimen sparing method (e.g., using micro techniques). The minimum amount allows for only one determination. The default unit is milliliters (ml).

8.8.11.12 OM4-12 Specimen Requirements (TX) 00652

Definition: This field contains the other requirements for specimen delivery and special handling (e.g., delivery within one hour, iced).

8.8.11.13 OM4-13 Specimen Priorities (ID) 00653

Definition: This field contains the allowed priorities for obtaining the specimen. Note that they may be different from the processing priorities given in OM1-25 - Processing Priority. When a test is requested, the specimen priority given in TQ1-9 - Priority should be one of the priorities listed here. Multiple priorities are separated by repeat delimiters. Refer to HL7 Table 0027 - Priority for valid values.

HL7 Table 0027 - Priority

Definition: This field contains the usual time that a specimen for this observation is retained after the observation is completed, for the purpose of additional testing. The first component is the duration, and the second component is an ISO time unit.

8.8.12 OM5 - Observation Batteries (Sets) Segment

The Technical Steward for the OM5 segment is ORDERS.

This segment contains the information about batteries and supersets (a nature code of F, P or S, as described in OM1-18 - Nature of Service/Test/Observation).

HL7 Attribute Table - OM5 - Observation Batteries (Sets)

8.8.12.1 OM5-1 Sequence Number - Test/Observation Master File (NM) 00586

Definition: This field contains the same value as the sequence number of the associated OM1 segment.

8.8.12.2 OM5-2 Tests/Observations Included Within An Ordered Test Battery (CE) 00655

Definition: This field contains the codes and names of all tests/observations included within a single battery (nature code P, as described in OM1-18 - Nature of Service/Test/Observation), a single functional procedure (nature code F), or a given superset (nature code S). When a segment includes a list of component elements, the sending system should be sure that the segments defining all of the components are sent before the segment that references them. An entry in this list can itself be a battery.

The individual service/test/observation IDs should be recorded as type CE, i.e., in the standard format for coded observation identifiers. Multiple observations should be separated by repeat delimiters.

If the definition segment defined serum electrolytes, this field might look like the following:

84132^potassium^AS4~

84295^sodium^AS4~

82435^chloride^AS4~

82374^HCO3^^AS4~

For S (superset) parameters, this field contains the batteries that are included within the "super" battery. For example, ROUTINES might be defined as:

402^Electrolytes~352^Urinalysis~432^CBC~520^SMA12

8.8.12.3 OM5-3 Observation ID Suffixes (ST) 00656

Definition: This field contains the tests or procedures that produce a type which uses observation ID suffixes following the service/test/observation ID code. This field lists the possible options. The applicable three-character mnemonics given in ASTM Table 20 (or others appropriate to the application) are listed, separated by repeat delimiters. For example, a chest X-ray may use the suffixes IMP, REC, DEV, or others. Each of the expected suffixes should be listed here.

8.8.13 OM6 - Observations that are Calculated from Other Observations Segments

The Technical Steward for the OM6 segment is ORDERS.

This segment contains the information about quantities that are derived from one or more other quantities or direct observations by mathematical or logical means.

HL7 Attribute Table - OM6 - Observations that are Calculated from Other Observations

8.8.13.1 OM6-1 Sequence Number -Test/Observation Master File (NM) 00586

Definition: This field contains the same value as the sequence number of the associated OM1 segment.

8.8.13.2 OM6-2 Derivation Rule (TX) 00657

Definition: This field is used when there are patient variables that are derived from one or more other patient variables (e.g., creatinine clearance, ideal weight, maximum daily temperature, average glucose, framingham risk). This field contains the rules for deriving the value of this variable (i.e., nature code C, as given in OM1-18 - Nature of Service/Test/Observation). These can be described in terms of humanly understandable formulas or descriptions.

When possible, however, they should be defined in terms of the Arden Syntax for specifying selection and transcendative functions and algebraic operations, ASTM E1460-92. Derivation rules that are represented in Arden Syntax should begin and end with an Arden slot delimiter (;;). Within this syntax, variables should be identified by OM1-2 - Producer's Service/Test/Observation ID. We recommend the use of the Arden Syntax because it permits the unambiguous specification of most such derived values and is a published standard for medical logic modules.

8.8.14 OM7 - Additional Basic Attributes (Fields That Apply to Most Observations/Services)

The OM7 segment contains additional basic attributes that apply to the definition of most observations/services.

HL7 Attribute Table - OM7 - Additional Basic Attributes

8.8.14.1 OM7-1 Sequence Number -Test/Observation Master File (NM) 00586

Definition: This field contains the value as the sequence number.

8.8.14.2 OM7-2 Universal Service Identifier (CE) 00238

Definition: This field contains the producer_s usual or preferred identification of the test or service. The test/service ID may be any of those included in ASTM tables 3 and 5, or a local code.

8.8.14.3 OM7-3 Category Identifier (CE) 01481

Definition: This field contains the category name (term given to a group of service items for the purpose of classification). Examples: Laboratory, Pharmacy, Diagnostic Imaging, etc. Refer to User-defined Table 0412 - Category identifier for suggested values.

User-defined Table 0412 - Category Identifier

Definition: This field contains a text description for the category of the test/service item.

Example: The category "Pathology" may be described as a specialty practice concerned with all aspects of disease, with special reference to the essential natural cause and development of abnormal conditions, as well as the structural and functional changes that result from the disease process.

8.8.14.5 OM7-5 Category Synonym (ST) 01483

Definition: This field contains an alternate name(s) for the category of the test/service. Example: The category "Radiology" is a synonym name for the category "Diagnostic Imaging".

8.8.14.6 OM7-6 Effective Test/Service Start Date/Time (TS) 01484

Definition: This field contains the date and time that the service item is available to be ordered, performed, etc.

8.8.14.7 OM7-7 Effective Test/Service End Date/Time (TS) 01485

Definition: This field contains the date and time that the service item is no longer authorized to be ordered, performed, etc.

8.8.14.8 OM7-8 Test/Service Default Duration Quantity (NM) 01486

Definition: This field indicates the default duration quantity for the service.

8.8.14.9 OM7-9 Test/Service Default Duration Units (CE) 01487

Definition: This field indicates the default duration units for the service.

8.8.14.10 OM7-10 Test/Service Default Frequency (IS) 01488

Definition: This field indicates the default frequency (how often) the service would be ordered for or performed on.

8.8.14.11 OM7-11 Consent Indicator (ID) 01489

Definition: This field indicates if a consent is needed for the service item. Refer to HL7 Table 0136 - Yes/no indicator.

Y A consent is required for service item to be ordered/performed.

N No consent is needed for service item to be ordered/performed

8.8.14.12 OM7-12 Consent Identifier (CE) 01490

Definition: This field contains the identifier for the consent specified for the service item. Refer to User-defined Table 0413 - Consent identifier for suggested values.

User-defined Table 0413 - Consent Identifier

Definition: This field contains the date and time the consent is valid for the service item.

8.8.14.14 OM7-14 Consent Effective End Date/Time (TS) 01492

Definition: This field contains the date and time the consent is no longer valid for the test/service.

8.8.14.15 OM7-15 Consent Interval Quantity (NM) 01493

Definition: This field specifies the period of time for which a consent is valid for a specific service item.

8.8.14.16 OM7-16 Consent Interval Units (CE) 01494

Definition: This field specifies the unit of time for OM7-15 - Consent Interval Quantity. Refer to User-defined Table 0414 - Units of time for suggested values.

User-defined Table 0414 - Units of Time

Note: If Consent Interval Quantity is specified, then Consent Interval Unit is required.

8.8.14.17 OM7-17 Consent Waiting Period Quantity (NM) 01495

Definition: This field contains the time period between the time the consent is signed and the procedure can be performed.

8.8.14.18 OM7-18 Consent Waiting Period Unit (CE) 01496

Definition: This field specifies the unit of time for OM7-17 - Consent Waiting Period Quantity. Refer to User-defined Table 0414 - Units of time for suggested values.

Note: If Consent Waiting Period Quantity is specified, then Consent Waiting Period Unit is required.

8.8.14.19 OM7-19 Effective Date/Time of Change (TS) 00607

Definition: This field contains the date and time of the last change in the test procedure that would make previous results incompatible with new results.

8.8.14.20 OM7-20 Entered By (XCN) 00224

Definition: This field contains the identity of the person who actually keyed the service item into the application. It provides an audit trail in case the request is entered incorrectly and the ancillary department needs to clarify the request.

8.8.14.21 OM7-21 Orderable-at Location (PL) 01497

Definition: This field contains the location(s) where the test/service can be ordered.

8.8.14.22 OM7-22 Formulary Status (IS) 01498

Definition: This field indicates whether or not the service (pharmaceutical) is in the formulary. Refer to User-defined Table 0473 - Formulary status for valid values.

User Table 0473 _ Formulary Status

Definition: This field indicates whether or not the service (pharmaceutical) is a special order. Refer to HL7 Table 0136 - Yes/no indicator for valid values.

Y This is a special order.

N This is not a special order

8.8.14.24 OM7-24 Primary Key Value - CDM (CE) 01306

Definition: Allows the ability to associate a Service/Test/Observation item with a CIM (charge item master). It is possible to allow multiple charge items to a single SIM item.

8.9 LOCATION MASTER FILES

8.9.1 MFN/MFK - Patient Location Master File Message (event M05)

This section is specifically concerned with describing a master file message that should be used to transmit information which identifies the inventory of healthcare patient locations, such as nursing units, rooms, beds, clinics, exam rooms, etc. In a network environment, this segment can be used to define patient locations to other applications. The segment also includes the readiness states and support locations for the patient locations.

The LOC, LCH, LRL, LDP, and LCC segments must be preceded by the MFI and MFE segments, as described in Sections 8.9.2, "LOC - Location Identification Segment," through 8.9.68.4." In the following message, the MFI-1 - Master File Identifier field should equal "LOC"

When the LCH segment appears immediately following the LOC segment, it communicates characteristics which are the same across multiple departments that may use the same room. When the LCH segment appears immediately following the LDP segment, it communicates characteristics which differ for different departments that may use the same room.

Master Files Query Response: When the LOC segment is used in the MFR message, the part of the message represented by: