Analysis of potentially inappropriate medications (PIM) used in elderly outpatients in departments of internal medicine by using the Screening Tool of Older Persons' Potentially Inappropriate Prescriptions (STOPP) criteria.

Abstract

Potentially inappropriate medications (PIMs) are associated with increased adverse drug reactions (ADRs), admission rate, and mortality rate in elderly patients. Here, we assessed PIM use in elderly outpatients in the departments of internal medicine in our center by using the Screening Tool of Older Persons' potentially inappropriate Prescriptions (STOPP) criteria. The clinical data of 13,221 outpatients aged ≥65 years in the departments of respiratory medicine, endocrinology, neurology, and cardiovascular medicine of a tertiary hospital from January 2016 to March 2016 were retrospectively analyzed. The incidence of PIM in these patients was assessed by using the STOPP criteria (2014 version). Multivariate logistic regression analysis was performed to identify risk factors for PIM use. It was found that 1,040 (7.87%) of 13,221 elderly patients had at least one STOPP-listed PIM, and a total of 1,785 PIMs were identified. The most commonly used PIMs were benzodiazepine, hypnotic Z-drugs (zolpidem), and antipsychotics. Multivariate logistic regression analysis revealed that age [odds ratio (OR) =1.032, 95% confidence interval (CI): 1.022, 1.042], gender (OR =0.783, 95% CI: 0.687, 0.892), number of prescribed medications (OR =1.134, 95% CI: 1.106, 1.163), and number of diagnoses (OR =1.450 95% CI: 1.391, 1.510) were significantly associated with PIM use. The incidence of PIM use was highest in the Department of Neurology (12.75%), followed by the Department of Cardiology (5.90%), Department of Endocrinology (4.94%), and Department of Respiratory Medicine (2.90%). The risk factors for PIMs varied among different departments: except that benzodiazepines and hypnotic Z-drugs (zolpidem) were 2 common PIMs in all departments, the remaining topranked PIMs were department-specific. PIM use in elderly patients in the outpatient departments of internal medicine is mainly related to age, gender, number of medications, and number of diagnoses. However, it varies among different departments, and the main PIM types are also department-specific. Thus, special attention should be paid to departments with a high incidence and a large number of PIMs, so as to promote rational use of medicines.