BackgroundHarm due to medications is common during the transition from hospital to home. Approaches that seek to prevent harm often involve isolated medication-related interventions and show conflicting results. However, until now, no review has focused on the effect of intervention components delivered both in hospital and following discharge from hospital to home.ObjectiveTo examine effects of medication-related interventions on hospital readmissions, medication-related problems (MRPs), medication adherence and mortality.MethodsFor this systematic review and meta-analysis, we searched the PubMed, Embase, CINAHL and CENTRAL databases without language restrictions. Citations of included articles were checked through Web of Science and Scopus from inception to 20 June 2019. We included prospective studies that examined effects of medication-related interventions delivered both in hospital and following discharge from hospital to home compared with usual care. Three authors independently extracted data and assessed study quality in pairs.ResultsFourteen original studies were included, comprising 8182 patients. Interventions consisted mainly of patient education and medication reconciliation in the hospital, and patient education following discharge. Nine studies were included in the meta-analysis; compared with usual care (n=3376 patients), medication-related interventions (n=1820 patients) reduced hospital readmissions by 3.8 percentage points within 30 days of discharge (number needed to treat=27, risk ratio (RR) 0.79 (95% CI 0.65 to 0.96)). Meta-regression analysis suggested that readmission rates were reduced by 17% per additional intervention component (RR 0.83 (95% Cl 0.75 to 0.91)). Medication adherence and MRPs may be improved. Effects on mortality were unclear.ConclusionsStudied medication-related interventions reduce all-cause hospital readmissions within 30 days. The treatment effect appears to increase with higher intervention intensities. More evidence is needed for recommendations on adherence, mortality and MRPs.