Abstract
BACKGROUND: Polypharmacy is a global public health concern. This study aimed to determine the prevalence of polypharmacy and trends in the use of commonly used and potentially inappropriate medications among older Korean patients. METHODS: Individuals aged ≥ 65 years who were prescribed any medication between 2014 and 2018 were selected from the Korean National Health Information Database. Joinpoint regression analyses were used to determine trends in the age-adjusted polypharmacy rates by age group. The prescription rates of the most commonly used medications and the most commonly used potentially inappropriate medications were analysed by year or age group for patients with polypharmacy using the chi-square and proportion difference tests. RESULTS: This study included 1,849,968 patients, 661,206 (35.7%) of whom had polypharmacy. Age-adjusted polypharmacy rates increased significantly between 2014 and 2018 (P = 0.046). Among patients with polypharmacy, the most commonly prescribed medications were aspirin (100 mg), atorvastatin, metformin, glimepiride, and rosuvastatin. The most commonly prescribed and potentially inappropriate medications were alprazolam, diazepam, amitriptyline, zolpidem, and dimenhydrinate. There was a significant decrease in the prescription rates for each of these drugs in 2018 compared with 2014 among patients with polypharmacy (all P < 0.001), whereas there was a significant increase in alprazolam prescription among patients aged ≥ 85 years when analysed by age group (P < 0.001). CONCLUSIONS: This study revealed an increasing prevalence of polypharmacy among older adults. Additionally, it highlighted that the utilisation of commonly prescribed potentially inappropriate medications, such as benzodiazepines and tricyclic antidepressants, has remained persistent, particularly among patients aged ≥ 85 years who practiced polypharmacy. These findings provide evidence-based guidance for the development of robust polypharmacy management strategies to ensure medication safety among older adults.