Potentially inappropriate medications at discharge among elderly patients at a single tertiary emergency medical institution in Japan: a retrospective cross-sectional observational study

Aim Potentially inappropriate medications (PIMs) are associated with a lower medication adherence and a higher incidence of adverse events and medical costs among elderly patients. The current study aimed to examine the prescription status of elderly patients transported to tertiary emergency medical institutions to compare the proportion of elderly patients using PIMs at admission and discharge and to investigate the characteristics of PIMs at discharge and their associated factors. Methods In total, 264 patients aged 75 years or older who were transferred to and discharged from the emergency room at Tokyo Medical University Hospital, a tertiary care hospital, from September 2018 to August 2019 were included in this study. We quantified the number of PIMs at admission and discharge based on the Screening Tool of Older Persons' Potentially Inappropriate Prescriptions (STOPP) criteria version 2. The primary outcomes were the proportion of elderly patients taking at least one PIM at admission and discharge. Results The proportions of patients taking PIMs at admission and discharge were 55% (n = 175) and 28% (n = 74), respectively. Old age, greater number of PIMs at admission, and greater number of medications at discharge were directly associated with PIMs at discharge. Conclusions Admission to tertiary care hospitals resulted in a lower number of prescribed PIMs. Elderly patients with a higher number of PIMs at admission and higher number of medications at discharge might have been prescribed with PIMs.