This Merck Academy lecture focuses on prescription medication adherence and the impact it may have on patient health outcomes. Patients try to listen carefully and attentively to their health care professionals who strive to explain things clearly so patients can act on what is recommended. However, some patients may not fill prescriptions, take medications appropriately, or even continue to take them for the appropriate length of time, which represents many missed therapeutic opportunities. Adherence is a challenging issue as drugs cannot work if patients don’t take them as intended.

The presentation reviews different types of medication nonadherence and some of the potential barriers to adherence. Different measurement tools for assessing adherence are described together with strategies that may help improve prescription medication adherence for all patients.