OSCAR EMR and FHIR

OSCAR (Open Source Clinical Application and Resource) EMR is a web-based electronic medical record (EMR) system initially developed for primary care clinics in Canada. Oscar is a Java spring based web application with a relatively old codebase. OSCAR is widely used in the provinces of Ontario and British Columbia and is supported by many Oscar service providers.

Fast Healthcare Interoperability Resources (FHIR) is an HL7 standard describing data schema and a RESTful API for health information exchange. FHIR is fast emerging as the de-facto standard for interoperability between health information systems because of its simplicity and the use of existing web standards such as REST.

OSCAR being primarily designed for primary care clinics does not support interoperability with other systems out of the box. FHIR in its entirety is not supported by OSCAR. A partial implementation of FHIR to support the immunization dataflow as FHIR bundles is available. One of the requests that constantly pops up in the OSCAR community is the need for a full FHIR API implementation for OSCAR.

We had some initial discussions on how to go about implementing a FHIR API for OSCAR EMR. FHIR is a REST API exposing FHIR Resources such as Patients, Observations and CarePlan as JSON resources. The HAPI-FHIR java library defines all the FHIR resources and the associated functions. The first step in building the API is to map the relatively messy OSCAR data model to FHIR resources. The Patient resource has been mapped and is available in the OSCAR repository. This (/src/main/java/org/oscarehr/integration/fhir/model/Patient.java) can be used as the template to map other required resources.

The next step is to extend the REST API that is currently available to expose FHIR APIs after authentication. If you have some ideas/expertise/interest in this, please comment below.