Validation of the transformed clinical practice research datalink (CPRD) GOLD and aurum data into the OMOP common data model.

Objective: To assesses the transformation of UK Clinical Practice Research Datalink (CPRD) databases into the Observational Medical Outcomes Partnership (OMOP) Common Data Model (CDM) version 5.3.1. Methods: A systematic approach was used to generate medical code lists and compare prevalent and incident counts between the source and OMOP CDM versions. Results: The results showed, for CPRD General Practitioner Online Database (GOLD) database, 89.5% of clinical events had no or very small differences in prevalent and incident event counts between the two versions of the database. The differences for CPRD Aurum were even smaller, with 97.4% of events showing no or very small differences in counts between the source and OMOP versions. Some observed discrepancies were due to codes being mapped into different tables. Conclusion: The study findings confirm the consistency of the OMOP transformation and provide confidence in analyses that query CPRD OMOP-transformed data.