{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,15]],"date-time":"2026-03-15T17:50:06Z","timestamp":1773597006321,"version":"3.50.1"},"posted":{"date-parts":[[2026]]},"group-title":"SSRN","reference-count":0,"publisher":"Elsevier BV","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"abstract":"<jats:p>Background: Consumer wearable devices collect clinical-grade physiological data directly by patients, yet less than 5% of this patient-generated health data (PGHD) reaches clinical systems.\u00a0\u00a0The European Health Data Space (EHDS) Regulation 2025\/327 mandates standardized health\u200b\u00a0data exchange, creating urgent need for validated transformation frameworks. Objective: To develop and validate a FHIR R4 Implementation Guide enabling multi-vendor\u00a0wearable data transformation for lifestyle medicine, documenting terminology gaps across seven vendor ecosystems.\u00a0Methods: We developed FHIR profiles, extensions, and ConceptMaps using a multi-layer\u00a0architecture covering eleven domains (six lifestyle medicine pillars and five wearable-specific). Technical validation included HL7 IG Publisher compilation, FHIR Validator conformance testing, and systematic terminology verification. Results: The IG comprises 74 profiles, 50 extensions, 14 CodeSystems, 174 ValueSets, and 28 ConceptMaps (546 artifacts). A two-phase terminology audit refined 1,173 custom codes to 718 without standard direct equivalents, including genuine gaps (RMSSD, pNN50), wearable-specific metrics, and granularity not yet addressed by LOINC or SNOMED CT. Build validation\u00a0produces 23 errors (all IPS upstream) and 73 warnings (97% non-actionable). Of six core HRV metrics, only SDNN has a LOINC code (80404-7). The multi-layer architecture achieved 75% weighted reuse across seven vendor ecosystems. Conclusions: This work extends the HL7 Physical Activity IG\u2019s \u201cTemporary Codes\u201d pattern into a semantic convergence buffer\u2014a vendor-neutral intermediary CodeSystem with outbound\u00a0ConceptMap coverage to LOINC, SNOMED CT, and OMOP enabling multi-vendor semantic convergence. The 75% weighted reuse and iterative terminology audits progressively reduce custom codes as standards mature. All profiles are vendor-agnostic and EHDS-compliant.<\/jats:p>","DOI":"10.2139\/ssrn.6409027","type":"posted-content","created":{"date-parts":[[2026,3,15]],"date-time":"2026-03-15T17:41:02Z","timestamp":1773596462000},"source":"Crossref","is-referenced-by-count":0,"title":["1 iOS Lifestyle Medicine FHIR Implementation Guide: A Multi-Vendor Data Interoperability Framework with Documented Terminology Gaps"],"prefix":"10.2139","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6017-8255","authenticated-orcid":true,"given":"Ricardo","family":"Lourenco dos Santos","sequence":"first","affiliation":[]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3764-5158","authenticated-orcid":true,"given":"Ricardo  Jo\u00e3o","family":"Cruz-Correia","sequence":"additional","affiliation":[]}],"member":"78","container-title":[],"original-title":[],"deposited":{"date-parts":[[2026,3,15]],"date-time":"2026-03-15T17:41:02Z","timestamp":1773596462000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ssrn.com\/abstract=6409027"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026]]},"references-count":0,"URL":"https:\/\/doi.org\/10.2139\/ssrn.6409027","relation":{},"subject":[],"published":{"date-parts":[[2026]]},"subtype":"preprint"}}