1. HL7 Electronic Data Exchange in Health Care
W. Ed Hammond, Ph.D.
President, AMIA
Vice-chair, Technical Steering Committee, HL7
Co-chair, Vocabulary Technical Committee, HL7
Co-chair, EHR SIG, HL7
Convenor, ISO TC 215, WG2
Professor, Community & Family Medicine, Duke University

2. Why standards in health care?
There is an assumed and inherent need to share data in the health care setting. The data are of many types and form and will be used for multiple purposes.
We must share both data and knowledge for both improved health care and for economic reasons.
Sharing becomes economically possible only if interoperability exists.
Interoperability occurs only if a full set of standards in health care exist.

3. Inpatient setting
Inpatient systems consist of many heterogeneous systems that must be integrated for efficient and effective care.
Service requirements that are essential parts of hospital information systems require communication between the requestor of a service and the supplier of the service.
Automated capture of data is most economical, most accurate, and most complete.
Patient safety and improved quality of care require the integration of data without the loss of information among many systems.

4. Steps to making a standard
Awareness of need for standard
Critical mass of technical expertise to create standard
Must insure fairness and not competitive advantage to a single vendor
Expertise must be both technical and domain
MUST involve vendors, providers, consultants, government
Global acceptance of standard
Requires education, balanced voting
Vendor implementation of standard usually driven by consumer pressure to implement
Visible reduction in cost and effort of interfaces as a result of standard

5. Different Kinds of Standards
Company
Dos
Windows
Consortium
Unix
Linux
Industry
DICOM
Government
NIST
CMS (UB92)
HIPAA
Voluntary consensus
ASTM
HL7
NCPDP

6. Consensus Standards Volunteer-driven Not full-time commitment
Uneven levels of participation
Uneven levels of understanding
Required resolution of negatives
Prone to compromise, often leading to ambiguity
Specialized balloting process (ANSI: requires 90% approval at membership level)

7. Multiple talents required for success
Administrative structure that supports the process but does not get in its way.
Political process that removes barriers to acceptance and implementation
Technical process that produces technically sound standard
Open process that does not slow or hinder production of standard
Funding process to create a standard in shortest, reasonable time
Commitment to life cycle of maintenance and update

8. A bit of history …
HL7 began in 1987 to permit the creation of an affordable Hospital Information System from a “best of breed” approach.
Standard was based on an implicit model based purely on the experience of the developers.
Limitations in technology defined the characteristics of the standard: character-based, character delimiters, position-defined.
First efforts addressed most important and frequent requirements.
Speed was important.
Acceptance took time.

9. Health Level Seven - Standards
Messaging Standard V2.4
Messaging Standard V2.4, XML Syntax
Messaging Standard V 3.0
Reference Information Model
Data Types
Clinical Document Architecture
Common Clinical Objects Working Group
Arden Syntax
Vocabulary
Clinical Guidelines
Decision Support
Clinical templates
Electronic Health record

10. Functional and Semantic Interoperability
Defined process for creating data interchange
Reference Information Model
Common Data Types
Common Terminologies
Common content specification at complex levels – a.k.a. clinical templates
Clinical document architectures
Conformance requirements
Document standards
Trigger Events

11. MDF Model Relationships
Analysis
Design
Requirements
Analysis
Use Case
Model
(UCM)
Domain
Analysis
Information Model
(DIM)
Interaction
Design
Model
(IM)
Message
Design
Hierarchical Message Descriptions
(HMD)
2-nd Order
1 choice of
0-n Drug
0-1 Nursing
Reference Model Repository
RIM

12. Interoperability Standards
Reference Information Model
Object Model that provides framework for the exchange and sharing of health data. EHR model must be based on this model.
HL7 has created such a model, accepted internationally, that is now becoming stable
HL7 model is high level requiring subsequent refined models for communications and storage of data.

13. HL7 RIM 1.15

14. HL 7 RIM Core Classes Relationship Link Act Relationship Entity Role
0..* 1
Act
Relationship 1
0..*
Entity
Role
Participation
Act 1
0..*
0..* 1
Organization
Living Subject
Material
Place
Health Chart
Patient
Employee
Practitioner
Assigned Practitioner Specimen
Referral
Transportation
Supply
Procedure
Condition Node
Consent
Observation
Medication
Act complex
Financial act

15. V3 Coded Data Types

16. Clinical Document Architecture
XML-based definition of clinical documents such as discharge summaries, op notes, progress notes, radiology reports, etc.
HL7 has ANSI approved standards. Work is based on 3 levels: (1) header; (2) header plus body structure and section headings; (3) element content specification and identification

17. Interoperability Standards (Concepts)
Clinical Data Model
Defines detail clinical object structures
Examples
CEN GPICS
HL7: 3M Clinical Data Models
HL7: Common Message Element Types
HL7: Clinical Templates
GEHR: Archetypes
ISO TC 215 WG2 has work item to harmonize these common conceptual elements (CHICS)
Require registry

18. Implementation/Conformance
Most frequently, ambiguity and options remain in standards at all levels. Total interoperability requires a precise definition of what will be sent to whom under what circumstances.
One example of this approach is DEEDS.
NEDSS will also provide this level of specification.

19. Methods
Work can be performed by a knowledgeable few; then get buy-in from group
Require use of standards by law
Sell value of standards; create a market
Demonstrations to prove standards work and to get publicity
Give publicity to vendors that use standards
Convince users to demand standards
Buy from vendors who use standards
Reduce confusion in market place caused by multiple, competing standards.

20. Final advice Total adherence to standard is most economical approach
Mapping of “your standard” to the standard is inefficient, expensive, out of date, and wrong.
A business case must be made for switching to the standard. Then the switch must be made in a timely fashion.
Governments must support standards.
If you know what must be done, do it now!