Older people living with frailty are at a higher risk of medication-related incidents due to frequent hospitalisation, complex health needs and polypharmacy. There is evidence that identifying patients at high risk of hospital readmission can enhance the impact of interventions to prevent readmission. However, there is insufficient evidence of the role of medication in readmission in this vulnerable patient group, and what pharmacists can do to reduce readmissions. This research used a mixed-method approach to examine the association between medicines-related risks and readmissions, and the pharmacists’ interventions thought to be important by key stakeholders to reduce readmissions. Medicines-related risks such as polypharmacy, potentially inappropriate medicines and high risk medicines did not have a strong association with repeated hospital admission in multivariable logistic regression. Patients who had multi-morbidities, and non-supported discharge, had a higher risk of repeated hospital admissions. A consensus survey study with three iterative rounds identified a list of pharmacists’ interventions viewed as high priority for reducing readmissions in frail elderly patients. The interventions with the highest scores included medicines reconciliation at discharge, on admission, preparation of discharge summary, provision of tailored patient education about medicines and inter-disciplinary working in ward rounds. A systematic intervention development method was used to further develop an intervention, underpinned by the theoretical domains framework. There is a need to further explore the role of medication-related risks in contributing to readmission using other validated tools and larger datasets. This could be used to inform development of future risk stratification tools to identify high risk patients in order to target interventions to maximise its impact. / University of Bradford and Sheffield Teaching Hospital studentship