HL7 - 1 CSE 5095 HL7: Organization, Standards, and Implementation Brendan Heckman CSE 5095 5/2/2011.

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HL7: Organization, Standards, and HL7: Organization, Standards, and ImplementationImplementation

Brendan HeckmanBrendan HeckmanCSE 5095CSE 50955/2/20115/2/2011

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PrefacePreface

Digitization of information and the Healthcare Digitization of information and the Healthcare IndustryIndustry Fragmentation of healthcare systems Inability for communication

Communication (send, receive, interpret) Nature of data (large and differentiated) Lots of data, no knowledge

Must abstract the problem above the system level Provide a means for interoperability

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Presentation ContentsPresentation Contents

Topics include…Topics include…

Introduction to HL7 Organization HL7 Messaging Standard HL7 Reference Information Model Other Standards Maintained by HL7 HL7 Use in EHRs/PHRs Case Studies Other Existing Standards Sets Evaluation of HL7 Final Thoughts

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Intro to HL7: The HL7 NameIntro to HL7: The HL7 Name The Term “HL7” stands for “The Term “HL7” stands for “Health Level SevenHealth Level Seven””

Reference to 7th layer in OSI Model Open Systems Interconnection Model 7th layer = Application Layer Defines data exchange, timing, and error handling

The name “HL7” is commonly used in two ways…The name “HL7” is commonly used in two ways… To represent the organization To represent the messaging standard

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Intro to HL7: The OrganizationIntro to HL7: The Organization Founded and started work in March 1987 at a Founded and started work in March 1987 at a

conference at University of Pennsylvania, USAconference at University of Pennsylvania, USA

Officially accredited as an SDO in 1994 by ANSIOfficially accredited as an SDO in 1994 by ANSI

Headquarters located in Ann Arbor MichiganHeadquarters located in Ann Arbor Michigan

All volunteer Non Profit OrganizationAll volunteer Non Profit Organization

Worldwide presenceWorldwide presence Local organizations in over 30 countries and

members in over 55 countries Members referred to as the “Working Group”

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Intro to HL7: Some Countries Involved Intro to HL7: Some Countries Involved ArgentinaArgentina Australia Australia BrazilBrazil ColumbiaColumbia CanadaCanada ChinaChina ChileChile DenmarkDenmark FinlandFinland France France GermanyGermany IndiaIndia

IrelandIreland ItalyItaly JapanJapan KoreaKorea LithuaniaLithuania MexicoMexico RomaniaRomania SpainSpain SwitzerlandSwitzerland TurkeyTurkey United KingdomUnited Kingdom UruguayUruguay

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Intro to HL7: Goals of the OrganizationIntro to HL7: Goals of the Organization Mission statementMission statement

Provide standards or interoperability that… Improve care delivery Reduce ambiguity Enhance knowledge transfer among all stakeholders

Exhibit… Timeliness Scientific rigor Technical expertise

Without Compromising… Transparency Accountability Practicality Needs of stakeholders

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Intro to HL7: Goals of the OrganizationIntro to HL7: Goals of the Organization Original goal, exchange between hospital systemsOriginal goal, exchange between hospital systems

Important to note: standards and protocols not Important to note: standards and protocols not software or hardware.software or hardware.

Tackle interface requirements through common Tackle interface requirements through common languagelanguage

Try to implement standards on a fast trackTry to implement standards on a fast track

Consider the requirements of preexisting systemsConsider the requirements of preexisting systems

Overall goal is to achieve interoperability in healthcareOverall goal is to achieve interoperability in healthcare

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Intro to HL7: InteroperabilityIntro to HL7: Interoperability Interoperability becomes multifacetedInteroperability becomes multifaceted

Technical Interoperability Physical means of communication, payload conveyance OSI – Levels 1-6

Semantic Interoperability Unambiguous communication of meaning/interpretation OSI – Level 7 (HL7)

Process Interoperability Shared human understanding of processes Essential for benefits

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Intro to HL7: Proliferation of the StandardsIntro to HL7: Proliferation of the Standards

Just to give you an idea…Just to give you an idea…

Most widely implemented healthcare data messaging system in the world

Approximately 1500 healthcare facilities (~2006, Shortliffe)

> 93% of organizations with Health IT systems use HL7

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Intro to HL7: Organization TimelineIntro to HL7: Organization Timeline

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Intro to HL7: Version TimelineIntro to HL7: Version Timeline

1.0 – September 19871.0 – September 1987 Defined the scope and format of the standards

2.0 – September 19882.0 – September 1988 Demonstration of data interchange

2.1 – June 19902.1 – June 1990 Widely implemented throughout the US & abroad

2.2 – December 19942.2 – December 1994 Becomes first ANSI approved healthcare

interchange American national standard

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2.3 – March 19952.3 – March 1995 Scope of HL7 messages greatly increased

2.4 – October 20002.4 – October 2000 Conformance of query protocols Message scope further expanded

Between 2.4 & 2.5Between 2.4 & 2.5 V 2.0 XML encoding syntax (ANSI) Makes HL7 web enabled

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2.5 – 20032.5 – 2003 Standard more functional and consistent than any

previous version

3.0 – (~ 2004)3.0 – (~ 2004) Reference Information Model Introduced RIM to be discussed later

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HL7 Messaging StandardHL7 Messaging Standard

What exactly does an HL7 message look like anyway?What exactly does an HL7 message look like anyway? Human readable* ASCII format

Unreadable without prior knowledge

Basic Components Segments Composites and Delimiters Type Differentiaton

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HL7 Messaging Standard: SegmentsHL7 Messaging Standard: Segments Each segment has its own line of text (120 types)Each segment has its own line of text (120 types)

Specific category of information, 3 character markerSpecific category of information, 3 character marker MSH – Message Header, info about message

PID – Patient Information, demographic info

NK1 – Next of Kin, contact info of relatives

PV1 – Patient Visit, describes hospital stay

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HL7 Messaging Standard: CompositesHL7 Messaging Standard: Composites Number of fields that make up a segmentNumber of fields that make up a segment

Primitive data types (character, string, number) or Primitive data types (character, string, number) or other composites other composites

Denoted by delimitersDenoted by delimiters

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HL7 Messaging Standard: TypesHL7 Messaging Standard: Types Each message has a typeEach message has a type

Located in the “MSH” segment (9Located in the “MSH” segment (9thth field) field)

Also determines what types of segments are availibleAlso determines what types of segments are availible

Example…Example… ADT^A04 represents “Register a patient”

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HL7 Messaging Standard: Interface EnginesHL7 Messaging Standard: Interface Engines Provide a layer of HL7 message management Provide a layer of HL7 message management

Eliminate the need to replace existing systemsEliminate the need to replace existing systems

Interpret and parse HL7 MessagesInterpret and parse HL7 Messages

Examples include… Iguana Chameleon 7 Edit Demo

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The HL7 RIMThe HL7 RIM Reference Information ModelReference Information Model

Collection of subjects, scenarios, classes, attributes, use cases, action, and triggers

Designed to depict information to specify HL7 messages Information model not a data model, for HL7

development Cornerstone of HL7 version 3.0

Goal is to merge standard notions of… Terminology Representation Data Exchange

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The HL7 RIM: DesignThe HL7 RIM: Design Model is based on an Object Oriented designModel is based on an Object Oriented design

Expressed in UML modeling languageExpressed in UML modeling language

The model is split into four componentsThe model is split into four components

Classes

Relationships

Attributes

Vocabulary Domains

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The HL7 RIM: ClassesThe HL7 RIM: Classes Backbone of the RIMBackbone of the RIM

Define broad categories of informationDefine broad categories of information

6 categories of Classes 6 categories of Classes Act Participation Role Entity Act-Relationship Role-Link

Each defines separate a aspect of the modelEach defines separate a aspect of the model

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The HL7 RIM: ClassesThe HL7 RIM: Classes ActAct

An actionable event, order med/lab result ParticipationParticipation

Entity’s function during a given action RoleRole

How and entity participates during an action EntityEntity

Object in the model that can act or be acted upon Act-relationshipAct-relationship

Represents how separate instances of Act inter-relate

Role-linkRole-link Represents how separate instances of Role inter-

relate

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The HL7 RIM: RelationshipsThe HL7 RIM: Relationships Two types…Two types…

Association Relationships Occur across the model Between the six core classes

Generalization Relationships Represented by “is a” relationship Occur between subclasses of the model

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The HL7 RIM: AttributesThe HL7 RIM: Attributes

Represent specific information about a class objectRepresent specific information about a class object

Hierarchical in natureHierarchical in nature Attributes are organized throughout the hierarchy Inherited such that children have attributes of

parents Children may add additional attributes

Structure removes inappropriate attributesStructure removes inappropriate attributes Through inheritance structure

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The HL7 RIM: Vocabulary Domains The HL7 RIM: Vocabulary Domains

RIM attempts to accounts for high degree in varying RIM attempts to accounts for high degree in varying terminology in healthcareterminology in healthcare

Defines vocabulary domain that are specific at class Defines vocabulary domain that are specific at class levellevel

Terminology unification is one of the biggest hurdles Terminology unification is one of the biggest hurdles in electronic healthcare information interoperabilityin electronic healthcare information interoperability

Standard libraries exist however…Standard libraries exist however… Adoption less than nominal

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Other Standards Maintained by HL7Other Standards Maintained by HL7

Arden SyntaxArden Syntax Syntax rule specification Rules can be formulated independent of computer

systems Later applied to systems being used in healthcare Aims to facilitate the sharing of knowledge to

generate a knowledge base

CCOW (Clinical Context Object Workgroup)CCOW (Clinical Context Object Workgroup) Interoperability specification for user experience Users experience integrated user session on the

desktop Enables “single sign on” experience

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Other Standards Maintained by HL7Other Standards Maintained by HL7

Clinical Document Architecture (CDA)Clinical Document Architecture (CDA) Exchange model for clinical documents Augments success of electronic medical records Utilizes XML, HL7 RIM, and coded vocabularies Documents are human and machine readable Using XML brings the CDA into the mobile scope

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HL7 use in EHRs/PHRsHL7 use in EHRs/PHRs

HL7 provides a standard for EHRs/PHRsHL7 provides a standard for EHRs/PHRs Reference of functions that may be present in an

EHR system List described from a user prospective to enable

consistent expression of system functionality Guidelines for exchange …

Among different PHR systems Between PHR and EHR systems

Standard is currently in draft status Despite this it is being used in some instances

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Case Study: HL7 and Home Monitoring Case Study: HL7 and Home Monitoring

Study from Kansas State UniversityStudy from Kansas State University

ProblemProblem Large amounts of data generated outside of

hospitals Doctors need secure and standardized way to

access this date

Goal SolutionGoal Solution Implement a home monitoring system that uses

secure HL7 to communicate between a home data base and a remote database (at the hospital).

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Case Study: HL7 and Home Monitoring Case Study: HL7 and Home Monitoring

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Case Study: HL7 and Home Monitoring Case Study: HL7 and Home Monitoring HL7 used to transmit from local DB to remote DBHL7 used to transmit from local DB to remote DB

Command from doctor packed into HL7 messagesCommand from doctor packed into HL7 messages Direct effect on home monitoring system Doctors can alter monitoring parameters remotely

Monitoring becomes active rather than passiveMonitoring becomes active rather than passive Greater flexibility More effective care

Uses Chameleon HL7 messaging clientUses Chameleon HL7 messaging client Can interface with Java, C++, VB, Etc. Encrypts data before sending

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Case Study: HL7 in a Collaborative HISCase Study: HL7 in a Collaborative HIS Research from National Taiwan University HospitalResearch from National Taiwan University Hospital

Studied implementation of HL7 in a collaborative Studied implementation of HL7 in a collaborative health information systemhealth information system

Prototype was implemented in outpatient registrationPrototype was implemented in outpatient registration

Implemented a set of web- services that directly map Implemented a set of web- services that directly map to HL7 standard message eventsto HL7 standard message events Message management acts as HL7 - IE

Event driven web services…Event driven web services… Decrease complexity Increase integrity

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Case Study: HL7 in a Collaborative HISCase Study: HL7 in a Collaborative HIS

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Case Study: HL7 Mobile MonitoringCase Study: HL7 Mobile Monitoring

HL7 based physiological monitoring system for HL7 based physiological monitoring system for mobile consumer devicesmobile consumer devices

Implement HL7 standard EHR with a trigger for video Implement HL7 standard EHR with a trigger for video conferencingconferencing

To be used on mobile device platformTo be used on mobile device platform

Automatically enable mobile video conferenceAutomatically enable mobile video conference

Promotes telemedicine Promotes telemedicine

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Other Existing Standard SetsOther Existing Standard Sets ASTM (American Society for Testing and Materials)ASTM (American Society for Testing and Materials)

Founded 1898, chartered 1902 Focused on standard test methods First healthcare data interchange standard (1984) Recently worked on Continuity of Care Record

standards (CCR) Served as a basis for HL7

IEEE (Institute of Electrical and Electronic Engineers)IEEE (Institute of Electrical and Electronic Engineers) MEDIX – standard for exchange between HIS

Merged into HL7 activities Medical Information Bus (MIB)

Standard for bedside medical device communication Defines entire 7-layer requirements set

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Other Existing Standard Sets (cont.)Other Existing Standard Sets (cont.) National Council for Prescription Drug ProgramsNational Council for Prescription Drug Programs

Create/promote data interchange standards for the pharmacy industry

Provide resources to educate the industry

American Dental Association (ADA)American Dental Association (ADA) All specifications for dental materials & equipment Promote concept of computer based workstations

Health Industry Business Communications CouncilHealth Industry Business Communications Council Health industry bar code standard Regulates bar code specifications for products in

the healthcare industry

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Evaluation of HL7Evaluation of HL7

ProsPros High level of abstractionHigh level of abstraction

Enables interoperabilityEnables interoperability

Supports outdated Supports outdated systemssystems

Established organizationEstablished organization

Active development Active development communitycommunity

World-wide presenceWorld-wide presence

ConsCons Steep learning curveSteep learning curve

Requires interface enginesRequires interface engines

Messages not very Messages not very readablereadable

Highly complexHighly complex

RIM subject to ontological RIM subject to ontological and logical flawsand logical flaws

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Final ThoughtsFinal Thoughts HL7 is currently the best solution to interoperability in HL7 is currently the best solution to interoperability in

healthcare information systemshealthcare information systems Can only get better with time and adoption

Although it very large and complex, it is out of Although it very large and complex, it is out of necessitynecessity The problem is equally large and complex

While there are other standards out thereWhile there are other standards out there None as generalized as HL7

HL7 attempts to solve all interoperability issues of the HL7 attempts to solve all interoperability issues of the healthcare industryhealthcare industry