The association of potentially inappropriate medications, polypharmacy and anticholinergic burden with readmission and emergency room revisit after discharge: A hospital-based retrospective cohort study

Aims: While certain drug-use indicators are known to be associated with clinical outcomes, the relationship is unclear for some highly prevalent conditions in in patients aged ≥65 years. We examine correlations between 3 drug-use indicators and postdischarge healthcare services use by older patients according to the presence of dementia, advanced age and frailty. Methods: This retrospective cohort study analysed data collected from hospital electronic health records between April and December 2017. Potentially inappropriate medications (PIMs) and anticholinergic burden were assessed using the 2015 Beers Criteria and anticholinergic cognitive burden scale (ACBS) score. Minor and major polypharmacy were defined as the use of 5–9 and ≥10 drugs, respectively. Outcomes were set as emergency room revisits and readmissions at 1, 3 and 6 months postdischarge. The correlation between drug-use indicators and outcomes was analysed by multivariable logistic regression. Results: The final cohort included 3061 patients for the analysis, and 2930, 2671 and 2560 patients were followed up to 1, 3 and 6 months after discharge. After controlling for confounders, all 3 drug-use indicators were significantly associated with readmission and emergency room revisits except for the relationship between PIMs and readmission within 6 months. These associations were significantly observed among patients without dementia, aged >80 years and with frailty. Conclusion: PIMs, polypharmacy and anticholinergic burden are common at discharge and correlate with future use of healthcare services. In older patients, the absence of dementia, advanced age and frailty should be given extra consideration with regard to medication safety.