LIS Interfaces: Basics, Implementation and Pitfalls

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Department of Public Health Sciences

LIS Interfaces:

Basics, Implementation and Pitfalls

James H. Harrison, Jr., M.D., Ph.D.

Division of Biomedical Informatics

Departments of Public Health Sciences and Pathology

University of Virginia

[email protected]

October 9, 2012

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Key Concept: Interoperability



The ability of systems to provide services to and

accept services from each other, and to use the

exchanged services to operate effectively

together



An interface is a communications connection and

translation mechanism between two systems that

may have different internal representations of

data



Laboratory interoperability: patient registration,

orders, specimens, results & reports

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Data Interoperability



Syntactic Interoperability

• Symbols are accurately exchanged



_{Semantic Interoperability}

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Digital Communications

ISO Networking Reference Model

Message

Structure

& Content

7 Application

Data model and semantics

6 Presentation

Characters, lines, delimiters, fields

5 Session

Authentication/authorization

Low Level

Transmission

4 Transport

End-to-end communication (TCP)

3 Network

Packet routing (IP)

2 Data Link

Ethernet, FDDI, etc.

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Digital Communications

ISO Networking Reference Model

Message

Structure

& Content

7 Application

Semantics

Data standards: HL7,

CLSI (ASTM), IHE, etc.

6 Presentation

Syntax

5 Session

Authentication/authorization

Low Level

Transmission

4 Transport

End-to-end communication (TCP)

3 Network

Packet routing (IP)

2 Data Link

Ethernet, FDDI, etc.

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MSH|^~\&|ADT1|GOOD EVN|A01|20070818112 PID|1||PATID1234^5^ NK1|1|NUCLEAR^NELDA PV1|1|I|200

Generic Interface Structure

EMR database

Lab

database

MSH|^~\&|ADT1|GOOD EVN|A01|20070818112 PID|1||PATID1234^5^ NK1|1|NUCLEAR^NELDA PV1|1|I|200 MSH|^~\&|ADT1|GOOD EVN|A01|20070818112 PID|1||PATID1234^5^ NK1|1|NUCLEAR^NELDA PV1|1|I|200 MSH|^~\&|ADT1|GOOD EVN|A01|20070818112 PID|1||PATID1234^5^ NK1|1|NUCLEAR^NELDA PV1|1|I|200

Message

construction

& parsing

Message

construction

& parsing

Mapping

Table

Mapping

Table

Transaction logs

Error logs

Messages:

Patient registration

Orders

Results

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Relevance of System Interfaces



EMR value proposition requires interoperability



HITECH incentives are increasing lab clients with EMR

• Ambulatory EMR < 25% in 2009 to > 80% by 2016



Meaningful Use requirements are evolving

• CPOE and lab reporting becomes required in MU 2

• Data content

• HL7 version progression (HL7 2.5.1)

• LOINC and SNOMED inclusion



Financial impact of implementation and upgrade

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Laboratory Interfaces

Analyzer

POC Devices & Base Station

Instrument

Manager

Analyzer

EMR

HL7

Interface Engine

Reference Laboratory

Ancillaries &

Research Systems

Community Providers

LPL System

LIS

Local Health System

VPN

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Instrument Interfaces

Reference Laboratory

Community Providers

VPN

LPL System

EMR

HL7

Interface Engine

Ancillaries &

Research Systems

Local Health System

Analyzer

POC Devices & Base Station

Instrument

Manager

Analyzer

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Instrument Interfaces



Connect instruments to LIS



Instrument manager may mediate

• POC manager is analogous



Unidirectional

• Enter accession # and test, send results once



Bidirectional

• Receive & store orders; barcoded samples; store and resend results

• Order broadcast/query across multiple analyzers; throughput issues



Data content

• Proprietary instrument drivers

• CLSI (formerly ASTM) standard, majority

• HL7 standard; new HL7-based profile from IVD Industry Connectivity

Consortium (IICC) and IHE

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Local System Interfaces

Analyzer

Reference Laboratory

Community Providers

VPN

POC Devices & Base Station

Instrument

Manager

Analyzer

LPL System

EMR

HL7

Interface Engine

Ancillaries &

Research Systems

Local Health System

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HL7 Messaging Standard



Health Level Seven International



A framework for messaging between

healthcare applications (ISO level 6 & 7)

• Version 2 released in 1988

• Version 2.3 (1997) widely deployed, 2.7 is current

• Version 3 released 2003



_{Membership required for use previously, now}

standards to be released at no cost

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HL7 Version 2



Defines message types for medical events:

admission/registration/discharge/transfer,

queries, orders, results, clinical observations,

billing, medical records, etc.



Defines transaction model for using the

messages (initiation, response, error handling)



Defines message structure (data fields), but

limited requirements for content

• Pragmatic standard that predated terminology

standards

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Admit Message (A01)

Segments, delimiters, fields, components & subcomponents

MSH|^~\&|ADT1|GOOD HEALTH HOSPITAL|GHH LAB, INC.|GOOD HEALTH HOSPITAL|

198808181126|SECURITY|ADT^A01^ADT_A01|MSG00001|P|2.5.1|

EVN|A01|200708181123||

PID|1||PATID1234^5^M11^ADT1^MR^GOOD HEALTH HOSPITAL~123456789^^^USSSA^SS||

EVERYMANÂDAMÂÎII||19610615|M||C|2222 HOME STREET^^GREENSBORO^NC^

27401-1020|GL|(555) 555-2004|(555)555-2004||S||PATID12345001^2^M10^

ADT1^AN^A|444333333|987654^NC|

NK1|1|NUCLEAR^NELDA^W|SPO^SPOUSE||||NK^NEXT OF KIN

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Result Message Example (ORU-R01)

MSH|^~\&|IDXLAB|UVAHSC|DADD||199808281130||ORU^R01|199808281130|P|2.2|||||

PID|||xxxxxxxx||lname^fname^mi||19980828|M|^^|||||||||3116488572||

PV1||OP|STFM^||||483230^lname^^fname

mi.(4201)|^||||||||||OP||||||||||||||||||||||||||

199808281115||

ORC|RE|320532-0^0||||||||||4201^lname^^fname mi.||||^||||

OBR||320532-0^0||CPBAS^BASIC METABOLIC PANEL^^CPBAS|||01012000^13:54|||^||||

01012000^13:54|^|4201^lname^^fname mi.(4201)||||M61675||||CHEM|F|CPBAS^CPBAS|

^^^^^R|^~^~^|||||||

OBX|1|NM|NA^SODIUM|1|137|mmol/L|136-145||||F|||01012000^14:15|UVA^|2886^AUTO^VERIFY|

OBX|2|NM|K^POTASSIUM|1|4.0|mmol/L|3.5-4.5||||F|||01012000^14:15|UVA^|2886^AUTO^VERIFY|

OBX|3|NM|CL^CHLORIDE|1|101|mmol/L|98-107||||F|||01012000^14:15|UVA^|2886^AUTO^VERIFY|

OBX|4|NM|CO2^CO2|1|24|mmol/L|23-31||||F|||01012000^14:15|UVA^|2886^AUTO^VERIFY|

OBX|5|NM|BUN^UREA NITROGEN|1|23|mg/dL|8.4-25.7||||F|||01012000^14:15|UVA^|

2886^AUTO^VERIFY|

OBX|6|NM|CREAT^CREATININE|1|1.0|mg/dL|0.7-1.3||||F|||01012000^14:15|UVA^|

2886^AUTO^VERIFY|

OBX|7|NM|GLUC^GLUCOSE|1|135|mg/dL|74-99|H|||F|||01012000^14:15|UVA^|2886^AUTO^VERIFY|

OBX|8|NM|CALCM^CALCIUM|1|9.8|mg/dL|8.4-10.2||||F|||01012000^14:15|UVA^|

2886^AUTO^VERIFY|

OBX|9|ST|GFRCAL^CALC GFR (mL/min/1.73m2)|1|>60||||||F|||01012000^14:15|UVA^|

2886^AUTO^VERIFY|

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Textual Results (ORU)

OBR||^|7352687|DIA0021^CHEST, SINGLE VIEW|||199808261230|||PS4|||||^^^ |993808^lname^fname mname||||||199808261230||RX|P||1^^^^^P^^PRIOR 1|||||990283&lname&fname mi&&&| |

OBX|1|TX|DIA0021GDT||PRELIMINARY-THIS IS A PRELIMINARY REPORT AND SHOULD BE VIEWED AS ||||||P| OBX|2|TX|DIA0021GDT||PRELIMINARY AND MAY BE AMENDED IN THE FINAL REPORT.||||||P|

OBX|3|TX|DIA0021GDT||PT ACCT NO: xxxxxxx||||||P| OBX|4|TX|DIA0021GDT||ORDER NO: 90001||||||P| OBX|5|TX|DIA0021GDT||EXAMINATION:||||||P|

OBX|6|TX|DIA0021GDT||DIA 0021 - CHEST, SINGLE VIEW EXAM DT/TIME: Aug 8, 1998 1:03AM||||||P| OBX|7|TX|DIA0021GDT||Accession No: ###### CPT: 71010. . . 28300713||||||P|

OBX|8|TX|DIA0021GDT||CLINICAL DATA: ,--TRAUMA ALERT ||||||P| OBX|9|TX|DIA0021GDT|| ||||||P|

OBX|10|TX|DIA0021GDT||FULL RESULT: Examination: Chest, single view, dated xx/xx/xxxx||||||P| OBX|11|TX|DIA0021GDT||||||||P|

OBX|12|TX|DIA0021GDT||COMPARISON: None ||||||P| OBX|13|TX|DIA0021GDT||||||||P|

OBX|14|TX|DIA0021GDT||FINDINGS:||||||P|

OBX|15|TX|DIA0021GDT||Single portable supine view of the chest. EKG wires overlie the ||||||P| OBX|16|TX|DIA0021GDT||patient. The lungs are without focal consolidation. Pulmonary ||||||P| OBX|17|TX|DIA0021GDT||vasculature is mildly cephalized, likely secondary to supine ||||||P| OBX|18|TX|DIA0021GDT||positioning. There is no evidence of pneumothorax or pleural ||||||P| OBX|19|TX|DIA0021GDT||effusion. The hila, mediastinum, and heart appear within normal ||||||P| OBX|20|TX|DIA0021GDT||limits for supine positioning and AP projection. ||||||P|

OBX|21|TX|DIA0021GDT||||||||P| OBX|22|TX|DIA0021GDT||||||||P|

OBX|23|TX|DIA0021GDT||PRELIMINARY-THIS IS A PRELIMINARY REPORT AND SHOULD BE VIEWED AS ||||||P| OBX|24|TX|DIA0021GDT||PRELIMINARY AND MAY BE AMENDED IN THE FINAL REPORT.||||||P|

OBX|25|TX|DIA0021GDT||||||||P| OBX|26|TX|DIA0021GDT||||||||P| OBX|27|TX|DIA0021GDT|| ||||||P|

OBX|28|TX|DIA0021GDT||IMPRESSION: ||||||P|

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Results Message Definition (ORU)

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Variability in HL7 Interfaces

Site 1:

OBX|1|CE|

ABO

^ABO GROUP||

O

^Type O|…

Site 2:

OBX|1|CE|

BLDTYP

^ABO GROUP||

TYPEO

^Type O|…

Site 3:

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Variability in HL7 Interfaces

Site 1:

OBX|1|CE|

ABO

^ABO GROUP||

O

^Type O|…

Site 2:

OBX|1|CE|

BLDTYP

^ABO GROUP||

TYPEO

^Type O|…

Site 3:

OBX|1|CE|

ABOTYPE

^ABO GROUP||

OPOS

^Type O|…

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LRI and LOI Initiatives



Standardize HL7 interfaces for ambulatory lab orders

and results as part of Meaningful Use



Based on HL7 2.5.1, with additional field content

requirements



Incorporates LOINC for test names, SNOMED for

non-numerical results including microbiology



Will require upgrade of most existing interfaces



http://wiki.siframework.org

• Laboratory Orders Interface

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Report Layout and Styling



No style or layout information in routine OBX segment;

reports are fragmented into separate lines



_{Possibilities for styled reports}

• RTF formatted text

• Marked up text (e.g., xhtml)

• PDF

• HL7 v. 3 clinical documents (XML, allows structured data)



Send as HL7 v. 2 messages using OBX field 5 or MIME

attachments? HL7 v. 3 interface?



_{Both sending and receiving systems must be able to}

handle the messaging strategy

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Goals for HL7 Version 3



_{Substantially reduce interface development time}

• Clarify spec for messages

• Fully-defined information model for messages



Method for conformance specification



Support modern communications infrastructures



Reference Information Model (RIM)

• Coherent shared information model

• Includes all content of HL7 messages

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HL7 RIM

Reference Information Model

Entities

Roles

Participation

Acts

Structured documents

Messaging

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HL7 v. 3 Status



Limited uptake since 2003/4 release



Most impact in clinical document arena

• Clinical Document Architecture (CDA)

• Combines structured and human-readable data

• Continuity-of-Care Document (CCD)



RIM and derived messages require special

modeling tools and are complex in practice

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HL7 FHIR



Fast Healthcare Interoperability Resources

• http://www.hl7.org/implement/standards/fhir/



New messaging strategy initiated 2011

• Simplified interoperability messages derived from the HL7 RIM, but

shielding complexity

• Messages are aggregates of resources that represent clinical concepts

(physician, patient, test, specimen) with defined data elements

• Individually understandable

• Expressed in XML with both structured data and human-readable

text (xhtml)

• Internet-standard communications (HTTP & Atom)

• Currently in draft for comment



Has potential to yield drop-in interfaces with both good visual

formatting of reports and machine-readable structured data

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Interface Implementation



Work with vendors of both systems

• Define HL7 v. 2 message set

• Compare data element representations in both systems

• Build mapping tables

• Implement communications in vendor frameworks

• Test results/reports (both correct and erroneous data)

• Validate data display in downstream systems



2 – 4 weeks of analyst time, $5,000 - $20,000



HL7 interface engine, ~$200,000 plus IT staff

• Data mapping and message processing based on rules

and scripts

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External Interfaces

EMR

HL7

Interface Engine

Ancillaries &

Research Systems

Local Health System

Analyzer

POC Devices & Base Station

Analyzer

Reference Laboratory

Community Providers

VPN

LPL System

Instrument

Manager

LIS

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External Interface Implementation



Reference laboratories

• HL7 Interfaces generally available



_{Physician offices}

• Ambulatory EMR, increasing numbers and variety



Affiliated hospitals and clinics

• In-patient/ambulatory EMR



Laboratory-Provider Link (LPL) systems

• Local device or vendor service

• Vendor handles interfaces with multiple client systems

• May be available through reference laboratories



Internet communications require data protection

• Periodic encrypted connection or VPN, access policies

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Interface Maintenance



Immediate response to communication problems

• Correct and resend failed transactions



Daily verification of operation



Daily check of error and transaction logs

• Problems include bad data (e.g., unknown physician)

• Correct and resend failed transactions



Latency measurements monthly



Editing and testing mappings (new physicians, test catalog

updates, locations, etc.)



Revalidation of data transmission and results display

biannually and after changes or upgrades

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Evolving Interoperability Challenges



Managing and synchronizing the test catalog across

multiple client EMR systems (explosion of mapping tables)



Mapping the test catalog correctly to LOINC



Managing the progression of reporting to both structured

data and better report formatting



Identifying patients across multiple client EMRs



Maintaining current downstream system validation when

those systems change



Report distribution across multiple systems

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Take-home Points



System interfaces form the crucial glue that holds multi-vendor

healthcare information systems together



Laboratories face interfacing challenges:

• Clients are moving to adopt a myriad of new EMR systems

• Regulations will require upgrade of current interfaces



The software and information design of system interfaces is well

established, but is not plug-and-play and additional standards

development is underway



Effective strategies to support internal and external interfaces

are available

• Significant effort and cost involved