Applying HL7 in the Acute Hospital setting

Philip Firth

IM&T Strategy Implementation ManagerWrightington, Wigan & Leigh NHS Trust

Philip.Firth@wwl.nhs.uk

Introduction

Look at some of the integration issues that Acute Hospital NHS Trusts typically need to address

Look at an example project with complex interface needs – accident & emergency

Look at requirements for linking Acute Hospital NHS Trust systems to LSP solutions and the Spine

Acute Systems Integration

Typical Issues

Issues …

Standards - what standards???

Implementation issues – PAS, Pathology

Data quality

Stylesheet issues

TIME

Standards - what standards???

Interface standards/output formats in Wigan– HL7 v2 (various implementations of)– EDIFACT– ASTM– System specific output – eg. Torex PAS

openlink

Acute Trusts need to learn to work with what’s available !!!

Implementation issues - PAS

PAS ‘real-time’ interface

No guarantee that messages would be delivered in the right order – Could get an Admission message prior to a Patient

Registration

Had to introduce a 15 minute time delay

Result: bed-status in EPR system slightly out of sink

Implementation issues - Pathology Handling previous results – append or overwrite?

– Microbiology – overwrite– Haematology, Chemistry – currently append

Collection date and time not always supplied Reference ranges can change

– Implication for graphing

Sensitive tests– What is the best way to deal with HIV, GUM, pregnancy

tests etc?

Implementation issues - Pathology Multiple patient IDs (NHS number, Hospital number) Multiple casenote numbers (Trust mergers)

– Need to establish systems for cross referencing patient IDs

Missing patient ID Pathology system sending internal patient ID Missing key patient data – DOB, Gender

– Unable to guarantee a match – need to Dump message

Data Quality Biggest issue by far is unique person referencing

Major education / change mgmt task to

– Get patient administration staff to register patient details accurately and avoid duplicates

– Get clinicians to use the Hospital / NHS Number

Problem especially big in emergency care

Issue has a huge knock on effect for the remainder of each episode care

Example: A consultant asked me to investigate why a particular chemistry result did not appear in the patient’s EPR record

In this instance the patient ID recorded in the Hospital Number field turned out to be the patient’s telephone numberMSH|^~\&|MLAB||||20040519113446||ORU^R01|X99156|P|2.3

PID|1||217779^^^^PAS~773702^^^^DEP||SURNAME^FORENAME^^^||19371113|M|||999 ACACIA AVENUE^ORRELL^WIGAN^^WN9 9XX|||||

ZMP|G3417810^^NAT^SS^^L|^^L

ZPV|AE|CAS^^^MLAB&RAEI&L^^W|&AP^PINTO^A.^^^Mr.|CAS^^^MLAB&RAEI&L^^W|&AP^PINTO^A.^^^Mr.|ACC|CC|CH|20177803|20040519|200405191026||FITS.|U||P

OBR|1||20177803^CCMLAB|CC_RUEGK^Urea, Elects. Gluc (urgent)^L^^^L|||20040519||||||FITS.|200405191026||&AP^PINTO^A.^^^Mr.||||||||CH|F||^^^20040519^S|

OBX|1|ST|CC_TONA^Sodium^L^44I5.^^RC||140|mmol/L|135-145|N|||F

Data Quality

Lesson: CANNOT use patient ID as the sole identifier – also need to cross reference with patient’s DOB, Gender, Surname …

Addressing data quality issues in Casualty

Solution Integrated emergency floor system

New emergency floor system is integrated with PAS to enable staff to retrieve up-to-date patient demograhics, including NHS Number

New emergency floor Pathology / X-ray requests automatically include patient ID - improvement departmental system data quality

New emergency floor system will be able to automatically register new patients on PAS - improvement 24 hour bed status

Patient ID data quality

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Addressing data quality issues in Casualty

Issues that are not so easy to address …

Real-time data capture – Not easy when an A&E receptionist is face to face with a patient

who is either • Confused• Uncooperative• Abusive• Unconscious

– Addressing these issues is proving to be a much more challenging task!!!

Addressing data quality issues in Casualty

Rapid application development approach :

(1) Present the HL7 results in the EPR test system environment via a stylesheet, and ask the domain experts for comments

(2) Amend stylesheet, and repeat (1) until domain experts are happy to sign off stylesheet design

(3) Implement stylesheet in live EPR system

Addressing presentation issues using XSL Stylesheets

Microbiology example - Legacy Pathology System view

Sensitivities in a fairly non user-friendly cross tabulation format

HL7v2 messages

A Culture and Sensitivity result is reported using multiple OBX segments.

A single organism result comprises an Organism OBX segment with subID N followed by an Organism Growth OBX segment with subID N followed by zero, one or more Organism Sensitivity OBX segments also with a subID value of N.

Microbiology

The final stylesheet design was deemed an improvement to the legacy system text based screen

More user-friendly cross tab for Organism vs Sensitivities

Critical issue - TIME Building interfaces is not a 5 minute job

Tasks TIME– Find funding to initiate project ? (show-stopper?)– Design interface, agree end-to-end requirements 1-3 months ?– Supplier set-up / configure interface 1-3 months ?– NHS Trust set-up / configure interface 1-3 months ?– End-to-end testing 1-3 months ?– On-going Stylesheet development ?

In summary, even a bog-standard unidirectional HL7 interface could take anything from 3 to 15 months, from start to finish

Key benefit of basing your integration architecture

around XML

EXCHANGE OF BOTH DATA AND

PRESENTATION

Data and Presentation Web technology is enabling the Trust to

benefit from both

Data exchange: development of interfaces which move XML patient data between an EPR (an XML clinical repository) and other departmental systems

Presentation: development and sharing of stylesheets which present a common view of departmental system data across multiple applications

ExampleBi-directional transfer of data and presentation between EPR and A&E EPR

Electronic Patient Records

Emergency FloorElectronic Patient

Records

Discharge Letters, Emergency Care summary

Pathology results, Patient demographics

Data and Presentation

JOIN

Shared XML data and stylesheets

Haematology result in the EPR system

Haematology result in the A&E system

Addressing issues and

Planning ahead for HL7 v3 messaging

Emergency Floor system design Change management issues

– A&E clinicians had never previously entered clinical data into a computer – all notes were recorded on a paper cascard

– Solution had to be QUICK and USER-FRIENDLY !!!

Single screen to record all discharge information

Order comms – all requests for investigations recorded

Treatment given – point and click

Drugs administered – point and click

Diagnosis – point and click

Clinician notes – free text

Emergency Care System

Emergency Floor system designSimple / Quick point and click data capture

Emergency floor system

Discharge screen auto generates an XML discharge summary message

Stylesheets to produce 2 documents on discharge:

(a) Patient letter

(b) GP letter

Emergency floor discharge summaries

Discharge summaries are currently stored in raw XML and presented on screen using an XSL stylesheet

Diagnosis values are coded ICD10, but can easily be coded in SNOMEDCT as well

Raw XML can be transformed into valid HL7v3 A&E Encounter and Provision of care messages using XSLT prior to routing to the Spine

NPfIT Integration Challenges

Existing Systems Integration

Replacement of NHS IT systems will not happen overnight in Acute Hospital Trusts

Key department systems may not be replaced before 2010

Existing systems integration is therefore a key issue for Acute Hospital Trusts

WWL / CSC NPfIT integration approach