A Critical Review of Medication Adherence in Hypertension: Barriers and Facilitators Clinicians Should Consider

Hypertension is a global public health problem, and its prevalence is increasing worldwide. Impacting all human societies and socioeconomic strata, it remains the major modifiable risk factor for global burden of cardiovascular disease all-cause mortality and the leading cause of loss of disability-adjusted life years. Despite increased awareness, the rate of blood pressure control remains unsatisfactory, particularly in low- to middle-income countries. Apparent treatment-resistant hypertension is associated with worse adverse health outcomes. It includes both true resistant and pseudo-resistant hypertension, which requires out-of-office blood pressure monitoring to exclude white-coat effect and confirmation of adherence to the agreed recommended antihypertensive therapy. The depth of medication non-adherence remains poorly recognized among medical practitioners, thus presenting an underestimated modifiable risk factor. Medication non-adherence is a complex and multidimensional variable with three quantifiable phases: initiation, implementation, and discontinuation, collectively called persistence. Non-adherence can be both intentional and non-intentional and usually involves several interconnected factors. Persistence declines over time in the treatment of chronic diseases like hypertension. The risk is higher in patients with new diagnosis, poor insurance status, polypharmacy, and multiple comorbidities, particularly psychiatric disorders. The World Health Organization divides the contributing factors impacting adherence into five categories. Screening and detection for medication non-adherence are challenging due to its dynamic nature and potential white-coat effect. Easy-to-conduct screening methods have low reliability and validity, whereas more reliable and valid methods are costly and difficult to perform. Medication non-adherence is associated with poor clinical outcome and potential negative impact on health-care costs. Evaluation of adherence should become an integral part of assessment of patients treated for hypertension. Medication adherence can significantly improve with a patient-centered approach, non-judgmental communication skills, and collaborative multidisciplinary management, including engagement of the patients in their care by self-blood pressure monitoring.