Factors Affecting Adherence to Statins in Hypercholesterolemic Kuwaiti Patients: A Cross-Sectional Study

Abstract

Objective: This study examined statin adherence amongst Kuwaiti hypercholesterolemic patients in order to identify factors associated with poor adherence and to determine whether or not an association exists between statin adherence and the risk profile of coronary heart disease (CHD). Subjects and Methods: Two hundred hypercholesterolemic patients (30-69 years of age) were recruited from Kuwaiti primary healthcare clinics and interviewed about demographic characteristics, pre-existing self-reported medical conditions and prescribed medications. The Morisky Medication Adherence Scale was used to assess statin adherence (a self-reported, medication-adherence questionnaire divided into 3 levels, with a score of 8 denoting high adherence, 6 to <8 denoting medium adherence and <6 denoting low adherence). Data regarding anthropometric, psychological and serum risk factors were collected using 2 additional questionnaires, laboratory tests and bioelectrical impedance scales. Binary logistic regression was used to determine predictors of adherence and general linear modelling was used to test relationships between continuous outcomes and statin adherence. Results: Of the 200 participants, 117 (58.5%) reported low adherence, 83 (41.5%) reported medium adherence and no patients (0%) scored high adherence. Younger patients (aged 30-50 years) had lower adherence than older patients (>50 years) [odds ratio (OR) 1.05; 95% confidence interval (CI) 1.01-1.09] for every extra year; p < 0.01). Those without diabetes, i.e. 113 (56.5%), were less likely to report medium adherence than those with diabetes (OR 0.42; 95% CI 0.23-0.75; p < 0.01). Low statin adherence was associated with higher levels of plasma cholesterol (p < 0.001) and low-density lipoprotein (p < 0.01). Conclusion: In this study, there was a high prevalence of low statin adherence, especially among younger patients with fewer concomitant diseases. The results indicated an inverse relationship between statin adherence and CHD risk profile.