Improving anti-hypertensive medication taking: The direct and interacting effects of perceived adherence difficulty, adherence knowledge, and commitment to adherence

Background: Non-adherence to anti-hypertensive medications is prevalent, leading to increased hospital costs and preventable deaths and disabilities. Managing patient perceptions of adherence difficulties may be key to improving adherence. Objective: This study examined the potential negative effect of patients' perceived difficulties with anti-hypertensive medication taking on adherence, along with whether and how that effect could be reduced through patient knowledge of and commitment to adherence. Method: 10,867 adult U.S. residents diagnosed with essential hypertension and prescribed anti-hypertensive medications participated in a cross-sectional online survey using self-reported behaviors and perceptions. Stepwise regressions and mean difference analyses were performed. Results: Perceived adherence difficulty was negatively associated with adherence behaviors (b = -.443, p < .001). This association was reduced by the moderating effects of adherence knowledge (b = .035, p < .001) and commitment to adherence (b = .008, p = .037), and their direct effects on adherence behaviors (b = .075, p < .001; b = .095, p < .001, respectively). Some differences by patient race-ethnicity and income were observed. Conclusions: Perceived adherence difficulty inhibits medication adherence but is countered by adherence knowledge and commitment to adherence. To improve adherence, healthcare strategies should strengthen patient knowledge and commitment by developing medication routines, engaging in self-care and awareness, and receiving tailored counseling on disease management, among others.