Comparative Analysis and Evaluation of State-of-the-Art Medication Mapping Tools to Transform a Local Medication Terminology to RxNorm.

Mapping local terminologies to standardized terminologies facilitates secondary use of electronic health records (EHR). Penn Medicine comprises multiple hospitals and facilities within the Philadelphia Metropolitan area providing services from primary to quaternary care. Our Penn Medicine (PennMed) data include medications collected during both inpatient and outpatient encounters at multiple facilities. Our goal was to map 941,198 unique medication terms to RxNorm, a standardized drug nomenclature from the National Library of Medicine (NLM). We chose three popular tools for mapping: NLM's RxMix and RxNav-in-a-Box, OHDSI's Usagi and Mayo Clinic's MedXN. We manually reviewed 400 mappings obtained from each tool and evaluated their performance for drug name, strength, form, and route. RxMix performed the best with an F1 score of 90% for drug name versus Usagi's 82% and MedXN's 74%. We discuss the strengths and limitations of each method and tips for other institutions seeking to map a local terminology to RxNorm.