Potentially inappropriate medication use at ambulatory care visits by elderly patients covered by National Health Insurance in Korea

Objectives: Potentially inappropriate medication (PIM) use is an important and preventable safety concern in the care of elderly patients and has been associated with adverse drug reactions, hospitalization, and mortality. Although PIM use for the elderly is a common and serious public health issue worldwide, there are few studies examining PIM use in the ambulatory care setting in Korea. Methods: To examine the prevalence and risk factors of PIM use from ambulatory care visits by elderly patients covered by National Health Insurance (NHI) in Korea, the nationwide prescription claims data of elderly patients' ambulatory care visits in 2006 were analyzed. Results: Potentially inappropriate prescriptions were identified using extensive criteria that included Beers', Zhan's, and Canadian criteria. In 2006, 3,770,978 elderly patients received 40,995,267 prescriptions. 36.7% of the total prescriptions for elderly patients who visited ambulatory care clinics were identified as PIM use. Findings in this study indicated that the strongest risk factors for PIM prescriptions were the number of drugs prescribed and visit characteristics. Conclusion: Therefore, it is necessary to develop the explicit criteria of PIM prescription in Korea that can be included in the Drug Utilization Review (DUR) system, which is expected to lead to more appropriate and judicious prescribing.