An Introduction to HL7 Version 2

1
An Introduction toHL7 Version 2
HL7 and its key role in NPfIT and Existing
Systems Integration

• Charlie Bishop
• 9 February 2005

2
Agenda

• History of v2
• Scope of v2
• Structure of the v2 Standard
• v2 Message Structure
• v2 Issues
• The Future

3
History of v2
Version 1.0
4
An International Standard

• USA (90 of hospitals)
• UK
• Canada
• Australia
• Netherlands
• Germany
• Japan
• Others

5
Scope

• Patient Administration
• Registration / MPI
• ADT / Inpatients
• Scheduling / Outpatients
• Waiting List (UK)
• Medical Records
• Clinical
• Orders
• Results
• Provision of Care
• Financial

6
Structure of the Standard

• Chapter
• Introduction
• Control
• Patient Administration
• Order Entry
• Query
• Finance
• Observation Reporting
• Master Files
• Medical Records
• Scheduling
• Patient Referral
• Patient Care
• Clinical Laboratory Automation
• Network Protocols

7
Message Structure

• Triggers
• Messages
• Segments
• Fields
• Data Types

8
Example v2 Message
MSH\LAB767543ADT76754320050201130405A
DTA04XX3657P2.4ltCRgt EVN200502011013142
0050201095000ltCRgt PID1234567891EXAMPLEDAVI
DS19590520M23 MAINSTREETANYTOWN gt
AN10 8SW01234 567890ltCRgt PD1DR A
WELBYltCRgt PV10NEWDR K JONESltCRgt
9
XML Representation

• Provides compatibility with industry standard
  tools
• Alternative syntax
• Data semantic is identical
• Simple transform between 2 syntaxes
• Segments, Fields and Data Types represented as
  elements

10
Example v2 XML Message
lt!DOCTYPE ADT_A04 SYSTEM "hl7_v231.dtd"gt ltADT_A04gt
ltMSHgt ltMSH.1gtlt/MSH.1gt
ltMSH.2gt\amplt/MSH.2gt ltMSH.3gt
ltCM.1gtLABlt/CM.1gt lt/MSH.3gt
ltMSH.4gt767543lt/MSH.4gt ltMSH.5gtADTlt/MSH.5gt
ltMSH.6gt767543lt/MSH.6gt ltMSH.7gt20050201130405lt/M
SH.7gt ltMSH.9gt ltCM_MSG_TYPE.1gtADTlt/CM_MSG
_TYPE.1gt ltCM_MSG_TYPE.2gtA04lt/CM_MSG_TYPE.2gt
lt/MSH.9gt . . .
11
Delimited vs. XML
MSH\LAB767543ADT76754320050201130405ADT
A04XX3657P2.4ltCRgt EVN2005020110131420050
201095000ltCRgt PID1234567891EXAMPLEDAVIDS1
9590520M23 MAINSTREETANYTOWNAN10
8SW01234 567890ltCRgt PD1DR A
WELBYltCRgt PV10NEWDR K JONESltCRgt
12
Issues

• Inconsistent use
• Multiple versions
• Z-Segments
• Interpretation
• Localisation

Seen one HL7 v2 interface
seen one HL7 v2 interface

• Support for clinical data
• Communication approach
• Broadcast vs. targeted

13
The Future

• HL7 v2 will continue to be developed
• HL7 v2 will continue to be widely used in the NHS
• Delimited vs. XML
• Mapping to v3
• HL7 UK v2 sub-group

14
Thank you!