Background China's aging adults are increasing, and have increasing prevalence of multimorbidity and polypharmacy, leading to a high risk of drug-drug interactions and adverse drug reactions. There are few studies on potentially inappropriate medication (PIM) in the elderly, and PIM in this group has not yet received sufficient attention clinically. Objective To perform a retrospective analysis of the PIM prevalence and associated factors in elderly outpatients in a hospital using the 2019 Updated AGS Beers Criteria? for Potentially Inappropriate Medication Use in Older Adults (hereinafter referred to as the 2019 Beers Criteria), providing precise medication guidance for clinical rational use of medications in the elderly. Methods Prescriptions of older outpatients written from January to December 2021 were collected from the "Smart Pharmacy Platform" of Changsha Hospital of Hunan Normal University on January 10, 2022. Each prescription was evaluated independently to find whether there was a PIM using the 2019 Beers Criteria. Multivariate Logistic regression was used to analyze the associated factors of PIM. Results The prescriptions of 39 275 outpatients were collected in the analysis, who had an average age of (74.0±6.8) years, an average number of diagnosed illnesses of (1.49±0.81), and an average number of types of drugs used of (2.70±1.75). The overall prevalence of PIM was 31.72% (12 458/39 275), involving 11 134 cases of drug-related PIM, 23 cases of disease- or symptom-related PIM, 2 109 cases of medication should be used with caution-related PIM in elderly patients, 99 cases of drug-drug interactions-related PIM that should be avoided in elderly patients, 2 cases of avoiding drug-related PIM and 8 cases of reducing drug-dose-related PIM in elderly patients with renal insufficiency. The departments with higher incidence of prescribing PIM were neurology〔1 908 (61.17%) 〕, geriatrics〔972 (49.49%) 〕, and general medicine〔1 495 (42.21%) 〕. The major prescribed PIM included benzodiazepines, proton pump inhibitors, oral nonsteroidal anti-inflammatory drugs, and glimepiride. Multivariate Logistic regression analysis showed that age, number of diagnosed illnesses and the number of types of medication were independently risk factors of PIM (P
