Clinical Metadata Exploration Ontology v1.2

CMEO is a metadata-centric ontology for describing, discovering, and comparing clinical studies when individual-level data cannot be shared. It provides a unified, FAIR-aligned representation of study protocol, variable-level semantics(codes, units, value sets, visit/time context), exploratory data summaries (EDA), and governance constraints (data-use permissions), enabling rich SPARQL querying for study exploration and harmonisation planning.

CMEO reuses and aligns with widely adopted ontologies—BFO, OBI, STATO, OBCS, IAO, RO, DUO, and SIO—and adds lightweight application classes only where existing coverage is missing. This release includes example named graphs (metadata-only) for multiple cardiovascular cohorts and one wearable dataset to demonstrate competency-question–driven queries (e.g., protocol retrieval, PICO-style study search, variable similarity across studies, missing-value encodings, categorical distributions, wearable-derived variables, governance-constrained reuse).