Clinical Trial Schedule of Activities Specification Using Fast Healthcare Interoperability Resources Definitional Resources: Mixed Methods Study

This study demonstrates that graph-based modeling, combined with targeted FHIR PlanDefinition extensions, enables an accurate and comprehensive representation of clinical study SoAs, including complex scheduling features that are not supported by current standards. These methods improve interoperability, reduce reliance on manual interpretation, and provide a basis for the automated integration of study protocols with electronic health records. While further tooling (eg, FHIRPath and clinical quality language) is needed for operational deployment, this approach offers a more precise and extensible solution for digital protocol implementation.