George N. Varghese, PharmD

Adherence is a complex behavioral process strongly influenced by environmental factors. Six posters designed to improve medication adherence were displayed in a medical clinic, with each poster displayed for 1 month. These posters were seen by clinic patients but, as passive measures, required no additional time on the part of clinicians. Medication adherence to antidepressant therapy was assessed for two 18-month periods. Days of therapy and median gap (the number of days a patient goes without medication before filling the next prescription) were similar between the periods. Medication possession ratio (MPR) was increased in the intervention period (0.974 vs 0.994 days). During the 6-month period that the adherence posters were displayed, persistence decreased by only 10% (versus 22% for the nonintervention period). Use of passive measures may improve patient medication adherence. In this prospective study, both the MPR and persistence were improved. (Drug Benefit Trends. 2008:20:17-24)