HL7 Message and Segment Usage

SEPG Coversheet

Work Product:    192-016 Health Level 7 (HL7) Message and Segment Usage 
Date Created:      April 18, 2001
Authors:              VISTA Data Systems and Integration (VDSI)

Reviewer	Date Sent for Review	Date Comments Received	Date Comments Incorporated	Comments Description
VDSI	1/29/01	4/18/01	4/18/01	Authors
SEPG	4/18/01	4/18/01	4/19/01	Review & Input
PMB	5/9/01			5/14/01	Tasked to PMC
PMC	5/14/01			5/16/01	Approved with revisions
PMB	5/17/01			5/21/01	Approved
ACIO	5/22/01			5/25/01	Approved/Signed

Description:  This procedure describes the requirements for documenting VISTA Messaging Interfaces and for registering them with the HSD&D Messaging Administrator.

Link to Document: http://vista.med.va.gov/sepg_lib/Standard%20Operating%20Procedures/192-016%20Health%20Level%207%20(HL7)%20Message%20and%20Segment%20Usage.doc

Document Stored:  SEPG Web site

Primary Audience:  Developers and the Messaging Administrator

Benefit:  The benefit of this SOP is to provide instructions on:
a.       Maintaining a central library of message specifications in use by the Department of Veterans Affairs (VA);
b.      Identifying the responsibilities of Developers and the Messaging Administrator;
c.       Establishing submission requirements; and
d.      Defining procedures for electronic submissions.

|| :  Project Management Committee (PMC), Program Management Board (PMB), and ACIO for HSD&D

Effective Date:  5/25/2001

Point(s) of Contact:  Pete Rontey

Related Links:    HL7 Standard
http://vista.med.va.gov/messaging/index.asp
VDSI Procedure for Technical Review
http://vista.med.va.gov/techreviews/default.htm



192-016 Health Level 7 (HL7) Message and Segment Usage
Standard Operating Procedure (SOP)
 
 
REVISION HISTORY

Date	Revision	Description	Author
5/25/2001	1.0	Initial Version	VDSI

OFFICE OF INFORMATION
DIRECTOR FOR HEALTH SYSTEMS DESIGN & DEVELOPMENT (HSD&D)
Health Level 7 (HL7) Messaging
April 2001

NUMBER 192-016

SUBJ: Health Level 7 (HL7) MESSAGE AND SEGMENT USAGE

1.   PURPOSE

This standard operating procedure (SOP) contains Health Systems Design and Development (HSD&D’s) policy and procedures for:

a. Maintaining a central message library of message specifications in use by the Department of Veterans Affairs (VA). This procedure refers only to the submission of a message and message constructs to the library. Message content, style, and message building rules are addressed in other documents, such as the HL7 Standard, and the VISTA Data Systems and Integration (VDSI) Procedure for Technical Review;

b. Identification of the responsibilities of Developers and the Messaging Administrator;

c. Establishing submission requirements; and

d. Defining procedures for electronic submissions.

2.   POLICY

a. Developers will use the central message library as a tool in the development of communications interfaces.

NOTE: The central message library will provide them with a convenient means of discovery and comparison, as well as a starting point for compiling new specifications. The ultimate aim of the library is to promote reuse of messaging constructs, uniformity of approach, and clearly identifiable standards of use.

b. The submitted document must ensure that a given message or message construct can be adequately classified and linked to constituent members within the library. In keeping with current VA usage, this document is aimed primarily at HL7 messages as specified in Appendix A. Where other message standards are used such as X12, developers must identify each of the component message constructs as fully as possible, and indicate their hierarchical relationships.

c. Submissions are encouraged as early in the development cycle as possible. Early submission can be beneficial in that reports necessary for reviews and group discussion can be derived from the library and are available centrally.

d. Submissions are to be made electronically to the Messaging Administrator. They must follow the procedure described in Section 4, below.

e. Messages may be modified throughout the process as required. The Messaging Administrator must approve all changes.

f. The central message library will be made available to developers through the HSD&D Intranet, and through the HSD&D Wide Area Network. Developers will access it through standardized query reports provided by the Messaging Administrator for this purpose. Specifications may also be obtained directly by telephone or mail request to the Messaging Administrator.

3.   RESPONSIBILITIES

a. Developers. Developers will submit message constructs electronically in accordance with the procedures in Section 4, below.

b. Messaging Administrator. The Messaging Administrator will review and incorporate specifications into the central library.

4.      PROCEDURES

a. Submissions are to be made electronically to the Messaging Administrator. They must follow the outline in Appendix A.

b. Two types of media are currently acceptable. They are (in order of preference):

(1) Submission via Excel Spreadsheet. It is highly recommended that, if at all possible, the user not start the specification from scratch (in the case of Z entities it may not be possible). The developer may request a "basis" specification from the Messaging Administrator to facilitate the submission. The "basis" specification will be an Excel document derived from the central message library. It will contain those message constructs that the developer indicates will be part of the object specification. The developer may use this "basis" document, with suggested element attribute values, to indicate changes or additions required in the final specification.

(2) Submission via Word Document. This method of submission is discouraged. It should be used only where the specification is not available in spreadsheet format as in the case of older specifications. If at all possible, the message constructs should be arranged in tables within the document.

c. When a messaging project is completed, a copy of the formalized documentation (Technical Documentation and/or Developer Documentation) describing the interface(s) involved must be submitted to the Messaging Administrator before or at the time of deployment to the field.

5.   REFERENCES

HL7 Standard

http://vista.med.va.gov/messaging/index.asp

VDSI Procedure for Technical Review

http://vista.med.va.gov/techreviews/default.htm

6.   RESCISSIONS

None.

7.   FOLLOW UP RESPONSIBILITY

Director, VISTA Data Systems and Integration

8.   FOLLOW UP DATE

April 2004





DAN G. BISHOP
Director for Health Systems Design & Development

Appendix A – Required Documentation Elements for Interface Specification Submission
Appendix B – Sample HL7 Application Specification Submission Worksheet

Required Documentation Elements for Interface Specification Submission


Application Description

This is a full description of the intended application of this interface. It should describe the following aspects of the interface.

Organizational Parties involved

Messaging standard employed (e.g. HL7 2.2, HL7 2.3 etc.)

Derivative specification (e.g. "derived from Philadelphia ADT specification")

Description of the subject applications (i.e. the clinical or administrative systems to be linked)

Development Platform (e.g. Fileman, Delphi, etc)
 

Message Documentation

The following elements are required to define a message in the Central Message Library.

• Message Type
• Event Type Code
• Order Control Type Code
• Message structure diagram (e.g. MSH,EVN,PID,PV1,[{NTE}],[IN1,IN2,IN3])
• Segments
• Segment Name
• Segment Mnemonic (e.g. PID, ZPD)
• Segment building API name
• Fields
• Field Name
• HL7 Item Number (where applicable)
• Sequence number (indicates sequence within segment)
• Field Length
• Data Type (e.g. DT)
• Repeatable (e.g. Y, no value interpreted as N)
• Quantity (if repeatable)
• Optional (e.g. R[equired],O[ptional],C[onditional]; no value interpreted as O)
• Table Number (e.g. 0003)
• Location within database – if used
• Tables
• Table Name
• Table Number
• Database location of table
• Table Element

• Value
• Database location of element
• Data Types
• Data Type Name
• Data Type Mnemonic (e.g. DT)
• Data Type Description
• Composite Description
• A string representing the position of each data type within the composite field

Sample HL7 Application Specification Submission Worksheet

Submitted by:

Specification Basis:

John Smith

HL72.3

Phone:

HL7 Version:

(518) 266-0100

2.2

E Mail:

Organization:

Health Level Seven

Submitting Organization:

New Application:

VA

XYZ HIS Interface

Msg Type

Event Type Code

Order Control Type Code

Event Description:

Structure:

Segment API:

ACK

A01

Admit a patient – acknowledgment

MSH, MSA, [ERR]

MSH^HLMA Seg ID Segment Name MSH Message Header Field Name Seq# Len DT R/O Rep Qty Tbl Item# Used DB Loc Description Field Separator 1 1 ST R N 00001 Y Describe the Database location e.g. ^HL(772.6,fld#3 This is actually created by HL7 Package in most instances Encoding Characters 2 4 ST R N 00002 Y N/A Sending Application 3 180 HD O N 00003 Y N/A Sending Facility 4 180 HD O N 00004 Y N/A Receiving Application 5 180 HD O N 00005 Y N/A Receiving Facility 6 180 HD O N 00006 Y N/A Date/Time of Message 7 26 TS O N 00007 Y N/A Security 8 40 ST O N 00008 Y N/A Message Type 9 7 CM R N 00009 Y N/A Message Control ID 10 20 ST R N 00010 Y N/A

MSA

Message Acknowledgement

GENACK^HLMA

Field Name Seq# Len DT R/O Rep Qty Tbl Item# Used DB Loc

Description

Acknowledgment Code

1

2

ID

R

N

0008

00018

Y

N/A

Message Control ID

2

20

ST

R

N

00010

Y

N/A

Text Message

3

80

ST

O

N

0020

Y

N/A