FHIR® Implementation Challenges in Clinical Research: A Case Study of the OrthoKids Platform

Health Level 7 Fast Healthcare Interoperability Resources (HL7® FHIR®) enables healthcare interoperability through standardized data exchange, yet implementing FHIR in complex clinical research environments reveals fundamental tensions between the standard’s flexibility and its core interoperability goals. This paper presents a comprehensive case study of the OrthoKids study implementation, examining practical challenges when using HL7 FHIR to build a clinical research data platform for pediatric orthopedic screening involving 12,500 participants and 200 specialists. Through systematic analysis of implementation decisions, this research identifies essential challenges that emerged when using FHIR for complex clinical study requirements and documents how these challenges were resolved while maintaining interoperability compliance. The study reveals critical limitations in standard FHIR workflow resources for complex examination pathways, demonstrating that Questionnaire resources provide superior modeling capabilities compared to PlanDefinition resources for multi-path diagnostic decision trees. The implementation required innovative combinations of FHIR’s access control mechanisms to address scenarios such as physician changes during treatment periods. The findings provide practical guidance for clinical research informatics by documenting concrete implementation patterns that maintain FHIR’s interoperability principles while addressing specialized requirements.