Integrating Garmin Wearable Data into FHIR-Based Health Systems for Improved Interoperability

As wearable technologies become more common in everyday life, integrating Patient-Generated Health Data (PGHD) into clinical systems has emerged as a critical area in digital health. This study explores how data such as heart rate, step count, sleep patterns, and activity levels (captured in this study via the Garmin Vívoactive 4 smartwatch) can be brought into FHIR-based healthcare systems through the Fitrockr platform. We explore how these data align with key Fast Healthcare Interoperability Resources (FHIR), such as Observation, Device, and Patient. Additionally, we evaluate the compatibility of collected datasets by the Modular Open Research Environment (MORE) platform with FHIR and examine the feasibility of transferring these records to FHIR servers. This level of semantic interoperability could simplify the integration of PGHD into hospital information systems or other healthcare information systems and especially EHRs, thus enhancing their contribution to care delivery, especially in medical decision making and as a source for Clinical Decision Support Systems (CDSS). The paper also discusses how standards like FHIR, openEHR, and Observational Medical Outcomes Partnership (OMOP) can work together to ensure consistent, meaningful integration of wearable data for both clinical practice and secondary analysis. In summary, we reflect on the importance of real-time wearable data availability, reliability, and privacy in supporting a more personalized, data-driven healthcare experience.