Psychological determinants of medication adherence in stroke survivors: a systematic review of observational studies

Abstract

Background: Medications targeting stroke risk factors have shown good efficacy, yet adherence is suboptimal. To improve adherence, its determinants must be understood. To date, no systematic review has examined psychological determinants that most influence medication adherence in stroke survivors. Purpose: To identify psychological determinants that most influence medication adherence in stroke survivors. Methods: In line with the prospectively registered protocol (PROSPERO CRD42015016222), five electronic databases were searched from 1953- 2015. Hand searches of included full text references were undertaken. Two reviewers conducted screening, data extraction and quality assessment. Determinants were mapped into the Theoretical Domains Framework (TDF). Findings: Of 32,825 articles, twelve fulfilled selection criteria (N=48,346 stroke survivors). Tested determinants mapped into 9/14 TDF domains. Data was too heterogeneous for meta-analysis due to variance in measurement of adherence and psychological determinants. In the primary studies, two TDF domains appeared most influential. Negative emotions (‘Emotions’ domain) such as anger, and concerns about medications (‘Beliefs about Consequences’ domain) were significantly associated with reduced adherence. Increased adherence was associated with stronger beliefs about medication necessity (‘Beliefs about Consequences’ domain). Study quality varied, often lacking information on questionnaire items used. Discussion: Five TDF domains did not appear to have been tested in the published literature. This may represent a “file drawer†problem or gap in research design. Future research should standardise medication adherence measurement and clearly report measurement of determinants to facilitate meta-analysis. It should also broaden the range of determinants explored to enable a more holistic understanding of medication adherence in stroke survivors.