Introduction: We aimed to summarize evidence on the effect of poor medication adherence on clinical outcomes and health resource utilization (HRU) among patients with hypertension and/or dyslipidemia.
Areas covered: A systematic review of studies reporting clinical outcomes and HRU for patients by status of adherence to antihypertensives and/or lipid-lowering medications was searched using Embase, MEDLINE, and MEDLINE In-Process and supplemented by manual searches of conference abstracts. In total, 45 studies were included, with most being retrospective observational studies (n = 36). Patients with poor adherence to antihypertensives and lipid-lowering medications compared with those with good adherence showed less reduction of blood pressure (BP) and low-density lipoprotein cholesterol (LDL-c) after 6-12 months follow-up (∆ systolic BP: 1.2 vs. -4.5 mmHg; ∆LDL-c: -14.0 to -18.9 vs. -34.1 to -42.0 mg/dL). Poor adherence was also significantly associated with a higher risk of cardiovascular events (HR: 1.1-1.9) and mortality (HR: 1.4-1.8) in patients with hypertension and dyslipidemia and increased HRU (i.e. outpatient visits, risk of cardiovascular-related and all-cause hospitalization, annual inpatient days, total health-care costs).
Expert opinion: Poor adherence is associated with poor clinical outcomes and increased HRU, highlighting the need to enhance medication adherence in patients with hypertension and/or dyslipidemia.
Keywords: Cardiovascular diseases; clinical outcomes; dyslipidemias; health resources; hypercholesterolemia; hypertension; medication adherence; systematic review.
High blood pressure is a leading cause of death and disease burden followed by high lipid levels in blood. Due to the silent nature of the diseases, patients can fall short of optimal medicinal treatment adherence and persistence, leading to poor outcomes and disease complications. The effectiveness of medicinal interventions depends on the appropriate medication-taking behavior of patients as lower adherence can lead to poor treatment benefits. Research was conducted to look for published studies that assessed the effect of lower medication adherence on clinical outcomes and health resource use among patients with high blood pressure, high lipid levels in blood, or both. Researchers were able to find 45 already published studies, from which 32 evaluated the use of blood pressure lowering medications and 7 evaluated the use of lipid-lowering medications, while 6 included patients treated with both types of medications. Refill of pharmacy prescription records was the most common method of assessing treatment adherence. Researchers found that patients with lower adherence to these medications compared with those with good adherence showed less decrease in blood pressure levels and less improvement in blood lipid levels after 6–12 months of follow-up. Patients who had lower adherence also had higher rates of cardiovascular events and deaths and increased usage of health services including visits to outpatient clinics, getting admitted to hospitals, and a longer stay of hospitalizations, leading to a higher overall healthcare cost. These findings suggest lower adherence is associated with poor clinical outcomes and increased health-care resource usage, highlighting the need to improve medication adherence in patients with high blood pressure and high lipid levels in blood.