title: The effect of competition on the relationship between the introduction of the DRG system and quality of care in Korea.
abstract: BACKGROUND
  The diagnosis-related group-based prospective payment programme was introduced in Korea in 1997 as a pilot programme to control health spending. In July 2013, the programme was implemented throughout the nation. The aim of our study is to evaluate the relationship between quality of care and market competition following the introduction of the new payment system in Korea.
  
  
  METHODS
  We conduct an observational analysis using National Health Insurance claim data from 2011 to 2014. We analyse data on readmission within 30 days, length of stay, and number of outpatient visits for 1742 hospitals and 821 912 cases. We use a generalized estimating equation model to evaluate readmission within 30 days and number of outpatient visits and a multi-level regression model to assess length of stay.
  
  
  RESULTS
  Total readmission within 30 days is 10 727 (1.3%). High competition areas present a lower risk of readmission [odds ratio (OR): 0.95, P: 0.0277], a longer length of stay (1%, P < 0.0001), and an increased number of outpatient visits (Relative Risk: 1.11, P: 0.0011) as compared with moderate competition areas. Risk of readmission is higher in low competition areas as compared with moderate competition areas (OR: 1.21, P < 0.0001).
  
  
  CONCLUSIONS
  The effects of the introduction of the new payment system differed by degree of market competition. Thus, evaluation about the effect of new payment system on hospital performance should be measured in combination with the degree of hospital market structure.
authors.affiliation: 1 Department of Public Health, Graduate School, Yonsei University, Seoul, Republic of Korea 2 Institute of Health Services Research, Yonsei University, Seoul, Republic of Korea.
authors.forename: Seung Ju
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: 2 Institute of Health Services Research, Yonsei University, Seoul, Republic of Korea 3 Department of Preventive Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Eun-Cheol
authors.initials: EC
authors.lastname: Park
authors.affiliation: 4 Department of Health Administration and Management, College of Medical Science, Soonchunhyang University, Asan, Republic of Korea.
authors.forename: Sun Jung
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: 1 Department of Public Health, Graduate School, Yonsei University, Seoul, Republic of Korea 2 Institute of Health Services Research, Yonsei University, Seoul, Republic of Korea.
authors.forename: Kyu-Tae
authors.initials: KT
authors.lastname: Han
authors.affiliation: 5 College of Pharmacy, Yonsei Institute for Pharmaceutical Sciences, Yonsei University, Incheon, Republic of Korea.
authors.forename: Euna
authors.initials: E
authors.lastname: Han
authors.affiliation: 2 Institute of Health Services Research, Yonsei University, Seoul, Republic of Korea 3 Department of Preventive Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors.forename: Sung-In
authors.initials: SI
authors.lastname: Jang
authors.affiliation: 2 Institute of Health Services Research, Yonsei University, Seoul, Republic of Korea 6 Department of Hospital Administration, Graduate School of Public Health, Yonsei University, Seoul, Republic of Korea thkim@yuhs.ac.
authors.forename: Tae Hyun
authors.initials: TH
authors.lastname: Kim
mesh_terms: D000328:Adult; D003953:Diagnosis-Related Groups / Q000706:statistics & numerical data*; D004465:Economic Competition / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007345:Insurance Claim Review; D007902:Length of Stay / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009313:National Health Programs / Q000706:statistics & numerical data*; D010359:Patient Readmission / Q000706:statistics & numerical data; D019984:Quality Indicators, Health Care / Q000706:statistics & numerical data; D011787:Quality of Health Care / Q000706:statistics & numerical data*; D056910:Republic of Korea