Analysis of medication and indication occurrences in clinical notes

A medication indication is a valid reason to use medication. Comprehensive information on medication and its intended indications has valuable potential applications for patient treatments, quality improvements, and clinical decision support. Though there are some publicly available medication resources, this medication and indication information is comprised primarily of labeled uses approved by the FDA. Additionally, linking those medications and the corresponding indications is not easy to accomplish. Furthermore, research that analyzes actual medication and indication occurrences used in real clinical practice is limited. In this study, we compiled clinician-asserted medication and indication pairs from a large cohort of Mayo Clinic electronic medical records (EMRs) and normalized them to the standard forms (ie, medication to the RxNorm ingredient and indication to SNOMED-CT). We then analyzed medication and indication occurrences and compared them with the public resource in various ways, including off-label statistics.