1. More Meaningful Use of CDA: the CDA-FHIR Bridge Robert Worden rpworden@me.com

2. Summary For Meaningful Use of CDA, you may need to compare an incoming CDA with existing information about the patient. This means matching patient data from the CDA, with data from an EHR FHIR can be the standard data format for matching and comparing This requires a three-component architecture All three components are easy to build Proof-of-concept implementations exist now This will encourage adoption of both CDA and FHIR

3. More Meaningful Use of CDA When reading a CDA, a physician is not just a blank slate for new information. Often, he or she knows about the patient already. The physician needs to compare the new information in the CDA with what they already know. Their knowledge of the patient may be stored in an EHR. Comparing requires matching of information from the CDA, with information in the EHR: – Match and identify the patient – Match clinical data for the patient (e.g. allergies, medications,..) Then (possibly) make updates to the EHR, at the physician’s discretion

4. CDA Handler Module: Extract patient data from CDA Search and match patients User chooses the matching patient Extract clinical information from CDA Compare with clinical information from application (User choice of updates to the application) Clinical Application (e.g. EHR) CDA Patient Search Parameters Candidate Matching Patients Selected Matching Patient Patient Clinical Information (Updates to Clinical Information) Architecture for CDA Match/Compare Few clinical applications support this now.

5. CDA-FHIR Bridge Clinical Application CDA FHIR adapter for application Search, Match and Display (FHIR client) Patient Resource Clinical Resources Searches on Patient Candidate Patient resources Searches on Clinical Resources Clinical Resources (Updates to Clinical Resources) search data (update) Searches on Clinical Resources FHIR-enabled CDA Match/Compare Three components simplify implementation. FHIR User

6. (1) CDA-FHIR Bridge Enables any incoming CDA as a small FHIR server The CDA ‘server’ supports FHIR searches on common resources (Patient, AllergyIntolerance,...) This is not a full transform from CDA to a FHIR Composition resource; extracting specific FHIR resources is much easier Transforms depend on CDA templates There will be a different bridge for each CDA profile There is no dependence on the EHR application – the bridge is universal for each CDA profile

7. (2) FHIR-Enabling an Existing Application Initially, read-only; to search for FHIR resources represented in the application. Done by mapping FHIR to the application’s APIs, or by mapping to the application database Mapping to a database supports many FHIR searches automatically (by generated SQL) It is easy to do ( < 1 man-month per resource) e.g. It is being done for the PAS in an NHS hospital in London (resources: Patient, Appointment,...)

8. (3) Search, Match and Display An interactive component Lives in a FHIR-only world (XML or JSON) Client to 2 or more FHIR servers (CDA, EHR,...) Functions: – Run searches on all connected FHIR servers – Match and display resources (e.g. in a table) – Allow the user to review, compare, match, take actions: Patient resource Clinical resources for the patient Proof of Concept implementation exists (on Eclipse) Can be web-based, tablet based Independent of CDA profiles, or EHR data model (depends only on supported FHIR resources) Can be universal, configurable

9. Three-Component CDA-FHIR Architecture: Summary Separation of components makes each one easy to implement: – CDA-FHIR bridge: depends only on CDA profile and FHIR resources supported – FHIR front-end for a clinical application: depends only on the application and the FHIR resources supported – Search, Match and Display: depends only on the FHIR resources supported Components can be developed and distributed independently Promotes adoption and competition

10. CDA-FHIR Bridge Clinical Application 1 FHIR adapter for Application 1 Search, Match and Display Patient Resource Clinical Resources search data update Searches on Clinical Resources Clinical Application 2 FHIR adapter for Application 2 search data update CDA Supporting Many Clinical Applications

11. CDA-FHIR Bridge (CDA Profile 1) Clinical Application 1 FHIR adapter for Application 1 Search, Match and Display search data update Clinical Application 2 FHIR adapter for Application 2 search data update CDA Profile 1 CDA-FHIR Bridge (CDA Profile 2) CDA Profile 2 Supporting Several CDA Profiles (e.g. cross-realm)

12. Conclusions Meaningful Use of CDA requires matching of CDA data with EHR data. FHIR is a simple standard format for matching The 3-component CDA-FHIR architecture is easy to build: – CDA-FHIR bridge (for a few key resources) – FHIR front-end to application (a few key resources) – Search, Match, and Display (pure FHIR, configurable) This can all be done now It will promote the adoption of both CDA and FHIR For more detail, see the white paper from rpworden@me.com rpworden@me.com