Interventions to enhance in-home taking medication among older adults with multimorbidity/polypharmacy: a systematic review and meta-analysis

Introduction Global population ageing is linked to increasing multimorbidity and polypharmacy. This shift places pressure on caregivers, who often lack training and face challenges like medication mismanagement. Our objective was to collate scientific evidence on interventions to enhance medication management among multimorbid older adults living in the community. Methods We conducted a systematic review and meta-analysis (PROSPERO: CRD42024513056) following PRISMA guidelines. PubMed, Web of Science, CINAHL, and ClinicalTrials.gov were searched up to July 9, 2024. Eligible studies were RCTs or quasi-experimental designs involving home-dwelling adults aged ≥60 years with ≥2 chronic conditions or ≥5 medications, assessing adherence or health outcomes, and ≥30 days of follow-up. Screening, data extraction, and quality assessment were performed in duplicate. Random-effects meta-analyses were conducted using R. ORs (95% CI) were calculated for binary outcomes and SMDs (95% CI) for continuous variables. Results Of 7,980 citations, 49 articles met the eligibility criteria, corresponding to 48 unique studies. Medication adherence measured with the MMAS-4 indicated a significant effect (OR = 1.55; 95% CI 1.08–2.28; I 2 = 32.4%), while continuous measures showed no effect (SMD = 0.00; 95% CI = -0.08–0.09; I 2 = 2%). Readmissions decreased at medium-term follow-up (OR = 0.41; 95% CI 0.25–0.69). Results for ED visits were inconclusive due to heterogeneity. Primary care contacts showed a weak, non-significant effect (SMD = 0.06; 95% CI = -0.04–0.16; I 2 = 42%). No effect was found for quality of life or mortality. DRPs and costs lacked conclusive evidence. Most studies had a moderate to high risk of bias. Certainty of evidence was very low. Discussion Interventions showed limited and variable effects. Adherence improvements were identified only for the MMAS-4, while other measures showed no benefit. A short-term reduction in readmissions was observed, but effects were not sustained, and the certainty of evidence was low. This review highlights evidence gaps, particularly the need for standardized outcomes, more sustained and multifactorial interventions, economic evaluation, and higher methodological quality, to support evidence-based policymaking and optimize future interventions. Systematic review registration The systematic review was registered in PROSPERO (CRD42024513056). The registration link is: https://www.crd.york.ac.uk/PROSPERO/view/CRD42024513056 .