Exploring pharmacoepidemiologic groupings of drugs from a clinical perspective.

Objectives: To investigate the extent to which pharmacoepidemiologic groupings are homogeneous in terms of clinical properties.
Methods: In our analysis, we classified drug subgroups from the pharmacoepidemiologic Anatomical Therapeutic Chemical (ATC) classification system based on clinical drug properties. We established mappings from ATC fifth level drug entities to drug property annotations in the National Drug File Reference Terminology (NDF-RT), including therapeutic categories, mechanisms of action, and physiologic effects. Based on the annotations for the individual drugs we computed homogeneity scores for all ATC groups and analyzed their distribution.
Conclusions: We found ATC groups to be generally homogeneous, more so for mechanisms of action, and physiologic effects than for therapeutic intent. However, only half of all ATC drugs can be analyzed with this approach, in part because of missing properties in NDF-RT.