Transcript documentcenter/public/wg/java/20111115_Jean_Duteau

gordon point informatics
www.gpinformatics.com
Moving from V2 to V3 –
Consequences of the RIM
RIMBAA Presentation
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November 14, 2011
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Agenda
• History of IBM’s Drug System
– Building a Drug System
– Creating V2 messages
• Make it use V3
– Could we map V3 like we did V2?
– Re-architect the application
• Lessons Learned
– Schemas vs Code Generation
– RIM and Vocabulary Bindings
– RIM Architecture Benefits
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History of IBM’s Drug System
Building a Drug System
• In 1999, Alberta Health and Wellness contracted IBM
to build a Drug Information System (DIS).
• The intent was to have Pharmacies provide real-time
data and the Physicians would browse this data using
a Web Viewer
• Eventual goal would be to have the DIS purely
function as a broker of information with a number of
external vendor systems browsing and providing new
data
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History of IBM’s Drug System
What does the system contain?
• The requirements were driven by consulting a
Working Group composed of Physicians – both
general practitioners and specialists, Pharmacists,
Nurses, and Hospital Administrators
• Focused on what should the Web Front end provide
and how it should be provided
• Functionality included three main categories:
– Prescriptions – the ordering of medications for a patient in
a community-care setting
– Dispenses – the supplying of medication to a patient
– Allergies
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History of IBM’s Drug System
How was it built?
• Since the requirements were driven by how the Web
Viewer would function, the data elements were
derived from what needed to be displayed on the
screen plus any data that was needed to derive that
data
• Example: Days Left of medication was a data element
– Drove Days Supply from the Dispense
– Dose Per Day from the Prescription
– Refills allowed from the Prescription
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History of IBM’s Drug System
Creating V2 Messages
• Once development got underway on the Web Viewer
and the business functionality and underlying data
structures, the decision on how to allow for
application-to-application communication was made
• HL7 V2.x Messaging was chosen as the medium using
the new V2-over-XML standard
• A team was brought on to develop the V2.x
specifications and the underlying application
functionality
•
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NOTE: This is where Lloyd McKenzie got started with HL7. I apologize for playing a
small role in the creation of the monster!
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History of IBM’s Drug System
Implementing V2.x Messaging
• All of the messages used existing V2.x messages but
we added a ton of Z-segments to support our needs.
• The specification basically took the requirements for
data that would drive the Web Viewer and
determined how we would send those over the wire.
• We had a number of stumbles – I believe that I
rewrote the V2 XML parsing piece at least three
times!
– V2.x messaging is hard!
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History of IBM’s Drug System
Final System Architecture
Database
HL7
Business Functionality
Viewer Support
Messaging
Web Viewer
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History of IBM’s Drug System
Implementing with External Vendors
• Once we had the implementation complete, we
began interfacing with external vendors.
• We produced V2.x schemas and sent those to the
vendors.
• They started building and a lot of them experienced
the same pain that we had in implementing V2.x
• We went live around 2006 with the first system-tosystem message in production!
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History of IBM’s Drug System
What had we accomplished?
• We had an architecture that was very Web Viewer
focused
– The business functionality supported the Web Viewer
– The data structures (and underlying database) supported
the Web Viewer
– The System-To-System messages supported the Web
Viewer
• It worked!
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Make It Use V3
Guidelines of V3 Project
• In the meantime, Canada Health Infoway was
developing a V3 pan-Canadian Specification for many
parts of the healthcare system, including Medication
Management.
JURISDICTIONAL INFOSTRUCTURE
Registries Data
& Services
Client
Registry
Provider
Registry
Ancillary Data
& Services
Outbreak
Management
Location
Registry
PHS
Reporting
Business
Rules
EHR
Index
Terminology
Registry
EHR Data
& Services
Shared
Health Record
Diagnostic
Imaging
Public
POINT OF SERVICEHealth
Provider
Pharmacy
System
Pharmacist
Health
Information
Normalizatio
n
Rules
Longitudinal Record Services
Common Services
Communication Bus
Public Health
Services
Laboratory
Message
Structures
HIAL
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Drug
Information
Data
Warehouse
Radiology
Center
PACS/RIS
Radiologist
Lab System
(LIS)
Lab
Clinician
Security
Mgmt
Data
Hospital, LTC,
CCC, EPR
Physician/
Provider
Privacy Data Configuration
Physician
Office
EMR
Physician/
Provider
EHR
Viewer
Physician/
Provider
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Make It Use V3
Guidelines of V3 Project
• Infoway approached IBM to adapt its Drug
Information System to use V3 messaging
• There were 72 transactions in the Electronic
Prescribing domain that they wanted to be
implemented
• By this time, IBM had implemented in a second
jurisdiction.
• IBM decided to abandon the V2.x solution and
replace it with V3 messaging
• After analyzing the transactions, 52 transactions
were deemed relevant to the application
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Make It Use V3
Can we just map V3 to our app?
• Challenge in how to implement the new interface
• Could we just replace the existing V2.x messaging
piece with a V3 piece?
• It was determined that our existing data model had
no real relationship to the underlying RIM model of
the V3 models
• The semantic difference between the V2.x messages
and the V3 models were so different that this was
not a feasible solution
• The new dynamic model was also an intractable
mapping problem
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Make It Use V3
Re-Architect Our Application
• We analyzed all of the V3 transactions
• Created a new Data model based on the data
required by the new transactions
– This ended up being an implementation of a constrained
version of the RIM
• Built a new business layer based on the new V3
dynamic model
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Make It Use V3
Re-Architect Our Application
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Make It Use V3
Keep our interface models separate
Database
HL7
Business Functionality
Messaging Support
Messaging
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Viewer Support
Web Viewer
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Make It Use V3
Sample of pan-Canadian RMIM
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Make It Use V3
Our RIM-based Data Model
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Make It Use V3
Keep our interface models separate
• This actually led to a better architected system
• Also led to a system that actually performed better!
• As we added more transactions, there was no
disruption of the Web Viewer
• Any changes to business functionality are done to
support just the business and not specifically for one
interface or another
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Lessons Learned
Lessons Learned
• Don’t use Schemas
• Don’t map Vocabularies
• Adding the RIM to your application is a good thing!
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Lessons Learned
Don’t Use Schemas (You’ve heard this before)
• The number of constraints in the pan-Canadian v3
messages and then in the jurisdiction specific
constraints could not be conveyed via Schemas
• We used a Code Generator to read the MIFs and
combined this with a set of XSL transform rules to
express our constraints on the MIFs
• The model is generated automatically and is mapped
by developers to the internal business model
• Hides the V3 message model from the business
model
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Lessons Learned
To use RIM and v3 Vocab, Don’t Map!
• We did not see a benefit in mapping a pre-existing
data model and pre-existing terminologies to the
RIM and to V3 codes
• A subsequent project, not done by IBM, took a
version of the application and tried to add V3
messages without changing the Web Viewer or the
existing V2.x messages
– Ultimately, this project too realized that there were
changes required to the underlying business model as
there was too much disconnect between the initial model
and the constrained-RIM models
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Lessons Learned
Adding RIM to models is a good thing!
• By being forced to “add the RIM” our application, the
architecture actually ended up being cleaner.
• Our performance was faster than the V2.x messaging
• Our underlying data model was easier to understand
since there was more semantics embedded in the
data model and the terminologies
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Questions & Discussion?
[email protected]
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