Abstract: The 12 included studies involved 10,953 residents in 355 (range 1 to 85) care homes in ten countries. Nine studies were cluster-randomised controlled trials and three studies were patient-randomised controlled trials. The interventions evaluated were diverse and often multifaceted. Medication review was a component of ten studies. Four studies involved multidisciplinary case-conferencing, five studies involved an educational element for health and care professionals and one study evaluated the use of clinical decision support technology. We did not combine the results in a meta-analysis due to heterogeneity across studies. Interventions to optimise prescribing may lead to fewer days in hospital (one study out of eight; low certainty evidence), a slower decline in health-related quality of life (one study out of two; low certainty evidence), the identification and resolution of medication-related problems (seven studies; low certainty evidence), and may lead to improved medication appropriateness (five studies out of five studies; low certainty evidence). We are uncertain whether the intervention improves/reduces medicine costs (five studies; very low certainty evidence) and it may make little or no difference on adverse drug events (two studies; low certainty evidence) or mortality (six studies; low certainty evidence). The risk of bias across studies was heterogeneous. We could not draw robust conclusions from the evidence due to variability in design, interventions, outcomes and results. The interventions implemented in the studies in this review led to the identification and resolution of medication-related problems and improvements in medication appropriateness, however evidence of a consistent effect on resident-related outcomes was not found. There is a need for high-quality cluster-randomised controlled trials testing clinical decision support systems and multidisciplinary interventions that measure well-defined, important resident-related outcomes.

Plain-language summary: We found 12 studies involving 10,953 residents in 355 care homes in ten countries that evaluated interventions to optimise prescribing for care home residents. Most of the interventions had several components, often involving a review of medicines with a pharmacist and doctor. Some interventions included a teaching component and one study used Information Technology (IT). We found no evidence of benefit of the interventions with respect to reducing adverse drug events (harmful effects caused by medicines) or death. One study led to residents having fewer days in hospital; however, the majority of studies did not show a benefit in relation to reducing hospital admissions. One study led to a slower decline in health-related quality of life. Problems relating to medicines were found and addressed through the interventions used in the studies. Prescribing was improved based on criteria used to assess the appropriateness of prescribing in five studies. We judged the overall quality of the evidence for the reported outcomes to be low for adverse drug events (harmful effects caused by medicines), hospital admissions, death, quality-of-life, medication-related problems, medication appropriateness, and very low for the cost of medicines. More high-quality studies need to be done to gather more evidence for these and other types of interventions. Further studies are needed to evaluate new technologies, including computer systems that support prescribing decisions. More work needs to be done to make sure that researchers are consistently measuring outcomes that are important to care home residents.