Methods and strategies for detecting and preventing nonadherence in resistant hypertension

Hypertension is one of the leading causes of death worldwide, and has been increasing in prevalence. A subset of hypertensive patients has resistant hypertension: blood pressure above goal despite taking three or more antihypertensive medications. While the diagnosis of true resistant hypertension requires medication adherence, many studies have found suboptimal adherence or complete nonadherence in resistant hypertensive patients. There are many factors that affect medication adherence, some more prevalent in the treatment of resistant and refractory hypertension, such as complex and expensive medication regimens. The greatest hurdle in preventing nonadherence is accurately measuring and monitoring adherence. There are various methods of monitoring medication adherence, both directly and indirectly, including questionnaires, pill counting, and blood plasma or urinary testing. These methods vary substantially in accuracy and common usage. This review covers the factors that affect adherence in resistant hypertensive patients and the methods used to assess adherence in these patients.