title: Factors Contributing to Increases in Prescription Drug Expenditures Borne by National Health Insurance in South Korea.
abstract: OBJECTIVE
  Rapid growth of prescription drug expenditures is a problem in South Korea. The objective of this study was to assess the contributions of four variables (therapeutic choice, drug-mix, original use, and price changes) to increases in drug expenditures paid by the National Health Insurance (NHI) in Korea.
  
  
  METHODS
  A retrospective cohort study was conducted between January 1, 2008 and June 30, 2012 utilizing data from the NHI Claims Database of the Health Insurance Review and Assessment Service. The number of target drug types for final analysis was 13959. To analyze the growth rates of drug expenditures, this study used Fisher ideal index and the Laspeyres and Paasche indexes.
  
  
  RESULTS
  With the exception of 2012, therapeutic choice contributed to about 40-60% of the increase in drug expenditures every year, while drug-mix contributed to another 30-40%.
  
  
  CONCLUSIONS
  The rapid growth in prescription drug expenditure was found to be largely due to drug-mix and therapeutic choice over time. Original use had little impact on drug spending.
authors.affiliation: Pharmaceutical Benefits Department I Director, Health Insurance Review & Assessment Service, Seoul, Korea.
authors.forename: Jeong Sook
authors.initials: JS
authors.lastname: Jo
authors.affiliation: Division of TB Epidemic Investigation, Center for Disease Control & Prevention, Cheongju, Korea.
authors.forename: Young Man
authors.initials: YM
authors.lastname: Kim
authors.affiliation: Division of Social Welfare, Baekseok University, Cheonan, Korea.
authors.forename: Kyung Won
authors.initials: KW
authors.lastname: Paek
authors.affiliation: Department of Preventive Medicine and Public Health, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Min Hee
authors.initials: MH
authors.lastname: Bea
authors.affiliation: Department of Preventive Medicine and Public Health, Ajou University School of Medicine, Suwon, Korea. ajoujkh@ajou.ac.kr.
authors.forename: Kihong
authors.initials: K
authors.lastname: Chun
authors.affiliation: Health Administration, Baekseok Arts University, Seoul, Korea. sjlee0820@bau.ac.kr.
authors.forename: Soojin
authors.initials: S
authors.lastname: Lee
mesh_terms: D015331:Cohort Studies; D005102:Health Expenditures / Q000706:statistics & numerical data*; D006801:Humans; D009313:National Health Programs / Q000191:economics*; D055553:Prescription Drugs / Q000191:economics*; D056910:Republic of Korea; D012189:Retrospective Studies
chemical_list: D055553:Prescription Drugs
keywords: Expenditures; prescription drugs; price changes