Effect of characteristics of pharmacotherapy on non-adherence in chronic cardiovascular disease: A systematic review and meta-analysis of observational studies.

Introduction: Cardiovascular medications are effective in prevention of cardiovascular diseases (CVD); however, medication non-adherence contributes to morbidity and mortality.

Objective: This systematic review and meta-analysis aims to summarise the evidence regarding the relationship between characteristics of drug therapy (pharmacotherapy) and medication non-adherence in the CVD population.

Methods: Systematic searches in PubMed, LILACS, Academic Search and CINAHL databases for observational studies that enrolled adults with CVD were performed, from January 1960 to December 2015. The meta-analysis tested the association between characteristics of pharmacotherapy and self-reported medication non-adherence outcome, using a random effects model. To investigate heterogeneity, we performed subgroup analysis and sensitivity analysis.

Results: Twenty-four cross-sectional studies and 7 cohort studies were included in this review. Based on 31 studies including 27 441 participants, we performed meta-analyses for all the characteristics of drug therapy that at least 2 studies evaluated, with a total of fourteen meta-analyses. The pooled results showed that studies which evaluate whether participants have insurance or another program that assists with medication costs, but not full coverage (OR = 0.63; 95% CI: 0.53-0.74; P < .001; I  = 0%, P = .938), and a dosing frequency of twice or more daily (OR = 1.38; 95% CI: 1.13-1.69; P < .001) were associated with non-adherence.

Conclusions And Relevance: The results of this review suggest that access to insurance or another program that assists with medication costs was a protection factor for non-adherence. On the other hand, a high frequency of dosing was a risk factor for non-adherence. Therefore, these characteristics of pharmacotherapy must be considered to improve medication adherence among CVD patients.