The association between multimorbidity and poor adherence with cardiovascular medications

Multimorbidity, defined as the presence of two or more chronic conditions, leads to a substantial public health burden. This study evaluated its association with adherence with cardiovascular medications in a Chinese population. A proportional stratified sampling was adopted to draw a representative sample of residents living in Henan Province, China. Interviewer-administered surveys were conducted by trained researchers. The outcomes included the number of chronic medical conditions, adherence with long-term medications (MMAS-8), and depressive symptoms (CESD-20). Binary logistic regression analysis was conducted to evaluate if medication adherence was associated with the presence of multimorbidity. From a total of 3866 completed surveys, the proportion of subjects having 0, 1 and > 2 chronic conditions was 62.6%, 23.8% and 13.5%, respectively. Among 27.6% who were taking chronic medications, 66.6% had poor medication adherence (MMAS-8 score <= 6). From binary logistic regression analysis, subjects with poor medication adherence were significantly associated with multimorbidity (adjusted odds ratio [AOR]: 1.35, 95% C. I. 1.02-1.78, p = 0.037). Other associated factors included older age (AOR = 1.04, 95% C. I. 1.03-1.05, p < 0.001), smoking (AOR = 1.63, 95% C. I. 1.16-2.30, p = 0.005), family history of hypertension (AOR = 1.51, 95% C. I. 1.19-1.93, p = 0.001), and fair to poor self-perceived health status (AOR = 2.15, 95% C. I. 1.69-2.74, p < 0.001). Using medication adherence as the outcome variable, multimorbidity was significantly associated with poor drug adherence (AOR= 1.34, 95% C. I. 1.02-1.77, p = 0.037). Multimorbidity was associated with poorer medication adherence. This implies the need for closer monitoring of the medication taking behavior among those with multiple chronic conditions. (C) 2014 Elsevier Ireland Ltd. All rights reserved.