Potentially Inappropriate Medications by Beers Criteria in Older Outpatients: Prevalence and Risk Factors

Background: Prescription of inappropriate medicine to elderly patients is a major public health care concern. The Beers criteria have been commonly employed as a screening tool to identify the use of potentially inappropriate medications (PIMs). The present study investigated the prevalence of PIM use according to the Beers criteria as well as factors related to PIM use. Methods: Data obtained from a retrospective survey included 25,810 outpatients aged >= 65 years from a university medical center in Seoul, Korea. PIMs were defined using the Beers criteria. Factors associated with PIM use were evaluated using multiple regression analysis. Results: Of all participants, 7,132 (27.6%) were prescribed at least one PIM. The most commonly prescribed PIMs were alprazolam (11.2%), clonazepam (10.8%), zolpidem (8.7%), quetiapine (8.4%), and hydroxyzine (5.4%). In multivariate logistic regression analysis, having five or more prescription medicines (odds ratio [OR], 11.32; 95% confidence interval [CI], 9.38 to 13.66) and five or more prescribing doctors (OR, 4.40; 95% CI, 3.59 to 5.39) were strongly associated with PIM. In a likelihood ratio test for trend, an increasing number of medications and prescribing doctors were both significantly associated with PIM. Conclusion: At a university medical center, the number of medications and the number of prescribing doctors was associated with PIM in older outpatients.