Cross-Institutional Data Harmonization for AI in Nursing Care Using the OMOP CDM

Artificial Intelligence (AI) offers potential to support and empower nurses, yet its development depends on the availability of high-quality, standardized data. Nursing data are often fragmented, unstructured, and semantically inconsistent, hindering their secondary use. This work aims to harmonize heterogeneous nursing data from hospitals and nursing homes to create an AI-ready data foundation. Following a generic harmonization process, example datasets from two institutions and software systems were extracted and mapped to the Observational Medical Outcomes Partnership Common Data Model (OMOP CDM). Using open-source tools, we performed dataset specification, vocabulary identification, coverage analysis, semantic and structural mapping, and initial ETL implementation. A core dataset was defined, covering key data elements such as demographics, vital signs, and medication. Initial test transfers demonstrated the feasibility of mapping and integrating nursing data, though complex nursing constructs such as care plans and assessments remain challenging. This study establishes a structured methodological approach for cross-institutional nursing data harmonization and lays the groundwork for the development of future AI applications in nursing.