Aim: To estimate the prevalence of good adherence to statin therapy and identify demographic and clinical factors associated with adherence among adults prescribed lipid-lowering therapy (LLT) for atherosclerotic cardiovascular disease (ASCVD) prevention.
Methods: We conducted a systematic search of PubMed and Scopus through May 2025 to identify randomized controlled trials, cohort, nested case-control, and cross-sectional studies evaluating adherence to statin monotherapy. Data were extracted on study design, participant demographics, comorbidities, adherence assessment method and duration, and statin type. A random-effects meta-analysis was performed. Study quality was assessed using the Newcastle-Ottawa Scale, and risk of bias in randomized trials was evaluated with the Cochrane RoB 2 tool. Subgroup and sensitivity analyses examined adherence variations by follow-up duration (<1, 1, >1 year), alternative adherence thresholds, and study quality. "Primary" non-adherence (failure to initiate prescribed therapy) was not reported in any of the included studies.
Results: Seventy-six studies encompassing 5,898,141 participants (median follow-up 24 months) were included. The pooled prevalence of good adherence (≥80% medication use) was 62.4% (95% CI: 58.3-66.5%), lower in primary (57.5%) than secondary (64.4%) prevention settings. Factors associated with lower adherence included female sex (RR=0.92), Black race (RR=0.66), smoking (RR=0.94), depression (RR=0.89), and heart failure (RR=0.96). Higher adherence was observed among older adults (RR=1.34), individuals with myocardial infarction (RR=1.28) or hypertension (RR=1.12), those with ≥2 comorbidities (RR=1.25), and patients with polypharmacy (RR=1.32). Subgroup and sensitivity analyses yielded consistent results.
Conclusions: Adherence to statin therapy remains suboptimal and is significantly influenced by demographic and clinical factors. Targeted strategies are needed to improve adherence, particularly in high-risk groups.
Keywords: Atherosclerosis; Cardiovascular Diseases; Medication Adherence; Meta-Analysis; Statins.
Statins are widely prescribed for the prevention and treatment of atherosclerotic cardiovascular disease (ASCVD), yet adherence to long-term therapy remains suboptimal. This systematic review and meta-analysis synthesizes evidence from 76 studies, including nearly 6 million individuals, to estimate adherence rates and identify the associated demographic and clinical determinants.Key finding 1: The pooled prevalence of good adherence (defined as ≥80% medication consumption) was 62.4%, with lower adherence observed in primary prevention (57.5%) compared to secondary (established ASCVD) prevention setting (64.4%). Decreased adherence is noted among women, younger adults, individuals with depression, current smokers, persons of Black or Hispanic ethnicity and heart failure patients.Key finding 2: Higher adherence is observed among older adults and those with a history of myocardial infarction, hypertension, or multiple comorbidities. Notably, polypharmacy (≥5 medications) is associated with greater adherence (a finding that contrasts with prior reports), which potentially reflects more intensive medical supervision or higher perceived cardiovascular risk in these populations and consorts with the higher adherence rates in those patients with established ASCVD. These findings underscore the persistent challenge of ensuring sustained statin use, particularly among populations with higher ASCVD risk. Despite robust clinical guidelines and extensive evidence of benefit, nearly 4 in 10 patients fail to maintain adequate adherence levels. Given the association between poor adherence and increased cardiovascular morbidity and mortality, targeted interventions—especially for high-risk groups—are warranted. Understanding adherence patterns is essential for optimizing the real-world effectiveness of lipid-lowering therapies and improving long-term cardiovascular outcomes.
© The Author(s) 2025. Published by Oxford University Press on behalf of the European Society of Cardiology.