Generic Utilization in the Korean National Health Insurance Market; Cost, Volume and Influencing Factors

Abstract

This study explores the prescribing pattern of generic drugs and the relationship between socio-demographic factors and the use of generics in South Korea. The analysis was based on claims data of 2011 from Korean National Health Insurance. We examined utilization, costs, and market share of oral preparations by original and generic product. Multiple logistic regression was performed to evaluate the predictive factors of generic use among multi-source medications. Gener-ics accounted for 37~41% of utilization and 34~41% of costs in the insured market of oral preparations. In the generic mar-ket, costly generics made up about 58~61%, 56~66% of volume and value, respectively. Other things being equal, institutional factors affected generic use to the largest degree. The odds of having generics were 6 times higher in clinics, 4 times higher in hospitals, and 1.7 times higher in general hospitals than in teaching hospitals. Those in metropolitan or rural area were more likely to prescribe generics than those in the capital area. While generics were frequently prescribed for off-site pharmacy (OR=1.173), the odds of having generics was 0.88 after weighting the data by units prescribed. This study empirically presented the pattern of generic prescribing, confirming the widely accepted view that costly generics were more likely to be utilized in the Korean market. Up to two thirds of the generic market consisted of costly products.The strongest factors affecting generic use were institutional variables.