Applying HL7 in the Acute Hospital setting

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Applying HL7 in the Acute Hospital setting

• Philip Firth
• IMT Strategy Implementation ManagerWrightington,
  Wigan Leigh NHS Trust
• Philip.Firth_at_wwl.nhs.uk

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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

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Acute Systems IntegrationTypical Issues
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Issues

• Standards - what standards???
• Implementation issues PAS, Pathology
• Data quality
• Stylesheet issues
• TIME

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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 whats
  available !!!

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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

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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?

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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

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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

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Example A consultant asked me to investigate
why a particular chemistry result did not appear
in the patients EPR recordIn this instance the
patient ID recorded in the Hospital Number field
turned out to be the patients telephone number
Data Quality
MSH\MLAB20040519113446ORUR01X99156P
2.3 PID1217779PAS773702DEPSURNAMEFO
RENAME19371113M999 ACACIA
AVENUEORRELLWIGANWN9 9XX ZMPG3417810NA
TSSLL ZPVAECASMLABRAEILWAPPINTO
A.Mr.CASMLABRAEILWAPPINTOA.Mr.A
CCCCCH2017780320040519200405191026FITS.U
P OBR120177803CCMLABCC_RUEGKUrea, Elects.
Gluc (urgent)LL20040519FITS.20040519
1026APPINTOA.Mr.CHF20040519
S OBX1STCC_TONASodiumL44I5.RC140mmol/L
135-145NF
Lesson CANNOT use patient ID as the sole
identifier also need to cross reference with
patients DOB, Gender, Surname
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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

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Integrated emergency system live
Addressing data quality issues in Casualty
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Issues that are not so easy to address
Addressing data quality issues in Casualty

• Real-time data capture
• Not easy when an AE 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!!!

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Addressing presentation issues using XSL
Stylesheets

• 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

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Microbiology example - Legacy Pathology System
view
Sensitivities in a fairly non user-friendly
cross tabulation format
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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.
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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
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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

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Key benefit of basing your integration
architecture around XMLEXCHANGE OF BOTH DATA
AND PRESENTATION
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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

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ExampleBi-directional transfer of data and
presentation between EPR and AE
Data and Presentation
Discharge Letters, Emergency Care summary
EPRElectronic Patient Records
Emergency FloorElectronic Patient Records
JOIN
Shared XML data and stylesheets
Pathology results, Patient demographics
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Haematology result in the EPR system
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Haematology result in the AE system
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Addressing issues andPlanning ahead for HL7 v3
messaging
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Emergency Floor system design

• Change management issues
• AE 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

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Emergency Care System
Emergency Floor system design
Simple / Quick point and click data capture
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• 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

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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 AE
  Encounter and Provision of care messages using
  XSLT prior to routing to the Spine

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NPfIT Integration Challenges
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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

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WWL / CSC NPfIT integration approach