title: Relationship between hospital volume and risk-adjusted mortality rate following percutaneous coronary intervention in Korea, 2003 to 2004.
abstract: OBJECTIVE
  There have been a large number of studies that have investigated the relationship between outcomes and provider volume for a wide variety of medical conditions and surgical conditions. The objective of this study was to explore the relation between hospital volume and risk-adjusted mortality following percutaneous coronary intervention between 2003 and 2004 in Korea.
  
  
  METHODS
  This is a retrospective analysis of database in National Health Insurance Review & Assessment Service and Korean National Statistical Office. The study data set confined to the ICD-10 diagnosis and procedure codes that were recorded in the National Health Insurance Review Agency. Risk modeling was performed through logistic regression and validated with cross-validation. The statistical performance of the developed model was evaluated using c-statistics, R², and Hosmer-Lemeshow statistic. Crude and risk-adjusted 30-day mortality was evaluated among patients who underwent Percutaneous Coronary Intervention (PCI) between 2003 and 2004 at low (less 200 cases/year), medium (200~399 cases/year), and high (400 cases or more/year) PCI volume hospitals.
  
  
  RESULTS
  The final risk-adjustment model consisted of ten risk factors for 30-day mortality. These factors were found to have statistically significant effects on patient mortality. The c-statistic and Hosmer-Lemeshow χ² goodness-of-fit test and the model's performance were good [R²=0.147, c-statistic 0.823, 4.1037 (p=0.8476)]. A total number of 60 low-volume hospitals (9.071 patients) and 27 medium-volume hospitals (15.623 patients) and 15 high-volume hospitals (19.669 patients) were included. Crude 30-day mortality rate was 1.4%, 1.1%, and 1.0% (p=0.0106) in each volume hospitals. But risk-adjusted mortality rate was not significantly different among three groups (1.3%, 1.0%, and 1.1% in each volume hospitals).
  
  
  CONCLUSIONS
  Although we found a significant different crude 30-day mortality rates according to hospital PCI volume, but did not find a relationship between hospital volume and 30-day risk-adjusted mortality rates following PCI in Korea.
authors: Division of Cardiology, Department of Internal medicine, Kangwon National University School of Medicine, Chuncheon City, South Korea.
authors: Yong Hoon
authors: YH
authors: Kim
authors: Ae Young
authors: AY
authors: Her
mesh_terms: D000328:Adult; D000368:Aged; D003324:Coronary Artery Disease / Q000401:mortality* / Q000628:therapy; D005260:Female; D017052:Hospital Mortality / Q000639:trends*; D061847:Hospitals, High-Volume / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D009313:National Health Programs / Q000592:standards; D017063:Outcome Assessment, Health Care; D062645:Percutaneous Coronary Intervention / Q000706:statistics & numerical data*; D012044:Regression Analysis; D056910:Republic of Korea; D012306:Risk; D015996:Survival Rate