A systematic review of patient self-reported barriers of adherence to antihypertensive medications using the world health organization multidimensional adherence model.

Multiple barriers can influence adherence to antihypertensive medications. The aim of this systematic review was to determine what adherence barriers were included in each instrument and to describe the psychometric properties of the identified surveys. Barriers were characterized using the World Health Organization (WHO) Multidimensional Adherence Model with patient, condition, therapy, socioeconomic, and health care system/team-related barriers. Five databases (Medline, Embase, Health and Psychological Instruments, CINHAL, and International Pharmaceutical Abstracts [IPA]) were searched from 1980 to September 2011. Our search identified 1712 citations; 74 articles met inclusion criteria and 51 unique surveys were identified. The Morisky Medication Adherence Scale was the most commonly used survey. Only 20 surveys (39%) have established reliability and validity evidence. According to the WHO Adherence Model domains, patient-related barriers were most commonly addressed, while condition, therapy, and socioeconomic barriers were underrepresented. The complexity of adherence behavior requires robust self-report measurements and the inclusion of barriers relevant to each unique patient population and intervention.