Presentation on theme: "1 NIST HL7 Conformance Testing Framework Justin Manweiler The College of William and Mary, class of 2007 Computer Science SURF Student Colloquium NIST."— Presentation transcript:
1 NIST HL7 Conformance Testing Framework Justin Manweiler The College of William and Mary, class of 2007 Computer Science SURF Student Colloquium NIST – Gaithersburg, MD August 8-10, 2006 OU: ITL Division: SDCT (897) Advisor: Rob Snelick Promoting HL7 Compliance to Improve Care
2 Focus Current state of healthcare IT HL7 messaging standard The role of NIST Personal work
3 Motivation Safety: much room for improvement … Up to 98,000 American deaths/year due to preventable errors (according to the Institute of Medicine) Mere existence of healthcare IT does not solve problem Lack of communication between diverse systems Need for enhancement of information and data systems Goal Strong informatics standards (provided by the HL7 standard) Correct implementations (facilitated by NIST) Realization of benefits possible with healthcare IT (improved care)
4 Health Level Seven (HL7) Standard Enables key healthcare data exchange Clinical and administrative messaging standard Example message types: lab order, report request, patient transfer Widespread basic usage 90% US hospitals, international use growing Expanded compliance would lead to… Superior quality of care Improved patient safety Reduction of costs
5 Major HL7 Shortcoming: Complexity Universal design problematic Needed to gain broad support Attempts to accommodate most business cases Overwhelmingly large Many optional features Systems difficult to implement/debug Plug-and-play installations impossible Described as “total chaos” Complexity limits effectiveness
6 Response: Message Profiles Allow for the customization/simplification of HL7 For a particular implementation Limit scope to a manageable size Specify optional constructs Path to conformance testing System interoperability requires strict profile compliance by each endpoint Conformance testing critical
8 The Role of NIST: Message Maker Created under Lead Scientist, Rob Snelick (Division 897) Dynamic test generator Produces a set of test messages Based on a system’s specific profile Form a customized testing suite
9 Personal Work Validation Infrastructure Profile Validation Support Message Validation Support Basic direct message-to-standard validation Message-to-standard validation chain Message-to-profile validation Profile-to-standard validation Supporting the Message Maker project.
10 Employed Technologies XML: eXtensible Markup Language Similar in structure to HTML Way of storing and describing data Java: object-oriented programming language DOM: XML representation as tree data structure XMLBeans: Java-to-XML data type binding XSLT: transformation of XML documents XML Schema: valid document structure definition Many XML technologies are utilized for validation as HL7 messages can be expressed as XML. Profiles are always in XML. HL7 XML Encoded Messages MSH|^~\&|REGA EVN|A05| PID|1||191919^ NK1|1|MASSIE^E NK1|2|MASSIE^I … HL7 ER7 Encoded Messages Conversion XML representation can be easily manipulated.
11 Profile Validation Strategy
12 Message Validation Strategy HL7 XML Encoded Messages Validation Messages Validation Report XML Schema Validator HL7-provided Message XML Schema Basic direct message-to-standard validation MSH|^~\&|REGA EVN|A05| PID|1||191919^ NK1|1|MASSIE^E NK1|2|MASSIE^I … HL7 ER7 Encoded Messages Conversion Refinement by DOM Modification Schema Violation Interpreter When a profile does not exist to validate against, HL7-provided schemas are used to perform basic validation.
13 Message Validation Strategy
14 … /HL7v2xConformanceProfile/HL7v2xStaticDef/ (/*:ADT_A01/*:MSH)/*:MSH.10 ((/*:ADT_A01/*:MSH)/*:MSH.10) Invalid content.... Cardinality error detected at Field 'Message Control ID'. Element must appear at least 1 time and no greater than 1 time in the message instance. … Message Validation Reporting Example error section of an XML message validation report. Reports provides as much detail as can be determined about detected errors. Location of the error Name of the error (classification) Textual description
15 Chaos Agreement Testability Verification Interoperability HL7 Standard HL7 Standard Goal: test suite Use Message Maker Build your own ($$$) Message Verification Benefits of the Message Maker Testing Framework Personal Work Impact: Message Profile Manual Test Suite tests needed for each profile written individually meticulous work high cost often tests not performed Message Maker Test Suite tests needed for each profile automatically generated easy lower cost increases likelihood tests will be performed Profile Verification
16 Acknowledgements My group, especially, My advisor, Robert Snelick Sydney Henrard The SURF ITL advisors, Tim Boland Larry Reeker Ivelisse Aviles