In Reply The implications of poor adherence are profound yet not readily appreciated. While studies of combination products may not have yielded significantly greater improvement in efficacy compared with administration of their constituents separately (perhaps because those studies were powered to detect differences in adherence and not differences in efficacy), patients in such studies are given the 2 separately prescribed agents. In real life, when patients are prescribed 2 or more agents, they are more likely to not fill 1 or more of the prescriptions, which surely limits the effectiveness of treatment regimen (if that is not so, the physician should not have prescribed the 2 products in the first place).
Feldman SR, Anderson K. Primary Nonadherence in Acne Treatment—Reply. JAMA Dermatol. 2015;151(10):1145. doi:10.1001/jamadermatol.2015.1744