Interventions to improve adherence among patients prescribed statins for primary prevention of cardiovascular diseases: a systematic review and meta-analysis

AIM: This study aims to identify the interventions used to improve adherence in patients receiving statins for primary prevention of CVD and to determine the effectiveness of these interventions. METHODS: This systematic review and meta-analysis was conducted according to PRISMA guidelines. The protocol was registered with PROSPERO (CRD42024587573). Search was performed in MEDLINE (PubMed), SCOPUS, EMBASE, and CINAHL for studies published between January 2000 and May 2024. RESULTS: Thirty-four studies with five intervention strategies met the eligibility criteria, of which 18 were non-cluster randomized controlled trials (ncRCTs), ten were cluster RCTs (cRCTs), and six were non-randomized studies of interventions (NRSI). The intervention strategies were multifaceted, education-based, behaviour change/monitoring, regimen modification, and incentive-based. Meta-analysis showed that the pooled risk ratio (RR), relative to control, for ncRCTs was 1.12 (95% CI, 1.00-1.25), for cRCTs it was 1.50 (95% CI, 0.97-2.31), and for NRSIs it was 1.37 (95% CI, 0.95-1.98), with point estimates in favour of the intervention arms. High heterogeneity was observed across studies, with I2>91%. Sub-group analysis suggested that relative to controls, there was a potential benefit of digital components in both ncRCTs (RR=1.08, 95% CI, 1.03-1.12) and cRCTs (RR=1.30, 95% CI, 1.07-1.59), and education-based (RR=1.05, 95% CI, 1.02-1.09) and/or multifaceted interventions (RR=1.11, 95% CI, 1.07-1.16) in ncRCTs. The interventions were effective in lowering LDL-C but were not as effective in lowering TC. CONCLUSIONS: The study found heterogenous evidence with limited certainty suggesting a potential modest improvement in statin adherence with interventions, where the effect sizes were small.