Medication adherence in patients with stable coronary artery disease in primary care

Abstract

Introduction: Lack of research targeting non-adherence to cardiovascular medications in Russia prevents from devel­oping effective interventions to improve adherence. The aim was to study medication adherence in patients with stable coronary artery disease in primary care.

Material and methods: The study was conducted in a primary care setting of Moscow. Demography, medical history, pharmacotherapy data were obtained retrospectively from 386 coronary patients’ medical records. Medication adher­ence was measured by 8-item Morisky Medication Adherence Scale (MMAS-8). A statistical analysis was performed using SPSS Statistics V16.0.

Results and discussion: According to the results from MMAS-8, 188 (48.7%) coronary patients had high medication adherence, 135 (35.0%) – moderate, and 63 (16.3%) – low. By the dichotomous interpretation: 48.7% (n = 188) – were adherent, 51.3% (n = 198) – were non-adherent. These groups were similar in gender distribution, age, and medical history profile (p > 0.1 for all variables). Smokers prevailed in the non-adherent group (13.6 vs. 5.3%; p = 0.009). Both groups were equally prescribed beta-blockers, antiplatelets, and statins (p > 0.1 for all). Use of fixed dose combinations (11.7 vs. 5.6%; p = 0.048) and the number of pills taken (mean 5.64 ± 1.52 vs. 5.99 ± 1.62; p = 0.029) were associated with better adherence. Higher values of total cholesterol (mean 5.2 ± 1.4 vs. 4.7 ± 1.2 mmol/L; p < 0.001) and low-den­sity lipoprotein cholesterol (mean 2.9 ± 1.2 vs. 2.4 ± 0.9 mmol/L; p < 0.001) were revealed in non-adherents. Subjects with suboptimal adherence visited general practitioners more frequently (median 5 vs. 3 visits; p = 0,003).

Conclusion: Medication non-adherence in coronary outpatients exceeded 50%. High adherence was associated with more frequent use of fixed dose combinations and fewer pills taken by patient. Smoking and poorer control of blood lipids prevailed in non-adherents, who also caused higher load on general practitioners.