COMPREHENSIVE REVIEW Community pharmacist interventions to improve adherence to lipid lowering medication and their influence on clinical outcomes: A systematic review and meta-analysis Ainhoa Oñatibia-Astibia MSc 1,2 | Amaia Malet-Larrea PhD 1 | Miguel  Angel Gastelurrutia PhD 1,3 | Begoña Calvo PhD 2 | Estibaliz Goyenechea PhD 1 1 Official Pharmacist Association of Gipuzkoa, San Sebastian, Spain 2 Pharmaceutical Technology Department, Faculty of Pharmacy, University of the Basque Country UPV/EHU, Vitoria, Spain 3 Pharmaceutical Care Research Group, Faculty of Pharmacy, University of Granada, Campus Universitario de Cartuja, Granada, Spain Correspondence Ainhoa Oñatibia-Astibia, Official Pharmacist Association of Gipuzkoa, Prim 2, 20006 San Sebastián, Spain. Email: ainhoaonatibia@redfarma.org Abstract Introduction: Non-adherence is a major problem among patients with chronic dis- eases. Community pharmacists are ideally positioned to detect non-adherence and to provide patient-centred interventions. Objective: To conduct a systematic review of the impact of community pharmacist interventions on patient adherence to lipid lowering medication (LLM) prescriptions and clinical outcomes. Search method: Five databases (MEDLINE, Cochrane Library, Science Direct, Scopus, and Web of Knowledge) were searched systematically to identify relevant reports published by December 2019. Study quality was assessed with the Cochrane risk of bias (RoB 2.0) tool. Selection criteria: Controlled trials in which community pharmacists conducted an intervention to improve patient adherence to LLM and clinical outcomes were evaluated. Main results: Five studies (2408 participants) were included in the qualitative analy- sis. Four studies (n = 2266) were pooled in the meta-analysis. Participants in the intervention group (IG) had better adherence than those in the control group (CG) [odds ratio (OR) = 1.67; 95% confidence interval (CI) 1.38-2.02; P < 0.001; I 2 = 54%]. Better adherence rates were obtained when adherence was measured with validated questionnaires than when medication-possession ratio (MPR) measure- ments were used. Total cholesterol (TC) levels were not included in the meta-analysis due to data variability among the studies. Conclusions: Pharmacist-led intervention can improve LLM adherence, but its influ- ence on clinical outcomes, including lipid level control, remains to be clarified. KEYWORDS community pharmacists, community pharmacy services, hypercholesterolemia, medication adherence, meta-analysis, systematic review Received: 2 March 2020 Revised: 4 July 2020 Accepted: 8 July 2020 DOI: 10.1111/jep.13451 J Eval Clin Pract. 2020;1–13. wileyonlinelibrary.com/journal/jep © 2020 John Wiley & Sons Ltd 1