Prevalence of and Risk Factors for Drug-Related Readmissions in Older Adults: A Systematic Review and Meta-Analysis.

BACKGROUND: Older adults are at an increased risk of drug-related problems, especially following discharge from hospital. Drug-related readmissions place a large burden on the patient and the healthcare system. However, previous studies report inconsistent results on the prevalence and associated risk factors for drug-related hospital readmissions in older adults.

OBJECTIVES: We aimed to assess the prevalence of drug-related readmissions in older adults aged 65 years and older and investigate the drug classes, preventability and risk factors most associated with these readmissions.

METHODS: A systematic review and meta-analysis were undertaken to answer our objectives. A search of four databases (MEDLINE, Embase, CINAHL and Scopus) was conducted. Three authors independently performed title and abstract screening, full-text screening and data extraction of all included studies. A meta-analysis was conducted to calculate the pooled prevalence of drug-related readmissions across all studies, and a subgroup analysis was performed to explore heterogeneity among studies reporting on adverse drug reaction-related readmissions.

RESULTS: A total of 1978 studies were identified in the initial search, of which four studies were included in the final synthesis. Three studies focused on readmissions due to adverse drug reactions and one study focused on readmissions due to drug-related problems. A pooled prevalence of 9% (95% confidence interval 2-18) was found for drug-related readmissions across all studies, and a pooled prevalence of 6% (95% confidence interval 4-10) was found for adverse drug reaction-related readmissions. Three studies explored the preventability of readmissions and 15.4-22.2% of cases were deemed preventable. The drug classes most associated with adverse drug reaction readmissions included anticoagulants, antibiotics, psychotropics and chemotherapy agents. Polypharmacy (the use of five or more medications) and several comorbidities such as cancer, liver disease, ischaemic heart disease and peptic ulcer disease were identified as risk factors for drug-related readmissions.

CONCLUSIONS: Almost one in ten older adults discharged from hospital experienced a drug-related hospital readmission, with one fifth of these deemed preventable. Several comorbidities and the use of polypharmacy and high-risk drugs were identified as prominent risk factors for readmission. Further research is needed to explore possible causes of drug-related readmissions in older adults for a more guided approach to the development of effective medication management interventions.