Adherence to topical therapy decreases during the course of an 8-week psoriasis clinical trial: commonly used methods of measuring adherence to topical therapy overestimate actual use.

Abstract

Medication nonadherence is common throughout medicine, and research into this area is increasing; however, knowledge about topical medication adherence is limited. A total of 30 patients were enrolled in a clinical trial for psoriasis and followed up for 8 weeks using 3 methods of adherence monitoring: electronic monitoring caps; medication logs; and medication usage by weight. Adherence rates calculated from the medication logs and medication weights were consistently higher than those of the electronic monitors (P <.05). Electronically measured adherence rates declined from 84.6% to 51% during the 8-week study (P <.0001). Female sex and increasing age by 1 year predicted improved adherence of 5% and 0.8%, respectively (P <.0001). The number of treatment gaps increased from the first half to the last half of the study, and weekend days were overrepresented in treatment gaps. Medication logs and weights do not ensure medication adherence to topical therapy. Electronic monitoring allows a more precise method of adherence measurement.