Understanding the Mechanism of FHIR APIs: Exchanging and Utilizing Healthcare Data

Details

This article describes how data exchange occurs between electronic health records and healthcare applications based on the FHIR (Fast Healthcare Interoperability Resources) standard. A concrete example is provided: an HTTP request of 'GET /Patient/123', which illustrates a simple read instruction. In FHIR, medical information like patient records are structured as 'Resources.' Applications utilize the mechanism of RESTful APIs—standard web technologies—to specify endpoints and request data. Crucially, headers such as authorization credentials (Authorization: Bearer <token>) and expected data format (Accept: application/fhir+json) are involved. The server performs access validation and permission checks before returning structured data in JSON format. This allows the application to parse the raw data, rather than displaying it directly, transforming it into user-friendly formats like patient profiles or clinical summaries for the end-user. FHIR's technical strength lies in maintaining a clinically meaningful data model while utilizing familiar web technologies. Concepts such as REST, endpoints, resource IDs, and HTTP status codes form the foundation, with security ensured through standards like OAuth 2.0 and SMART on FHIR.