Highlight
– Nearly half of SCCM’s C2D2 elements map directly to OMOP concepts; most remaining elements need modification or extension.
– Ventilator parameters, composite scores, and temporally precise measurements are the main sources of incompatibility.
– Large language model semantic matching showed high recall but modest precision, indicating a helpful but imperfect tool for mapping.
– Communities must choose between extending OMOP, adapting C2D2 for OMOP compatibility, pursuing vocabulary inclusion via OHDSI, or partnering with EHR vendors for native standards support.
