title: Effect of hospital volume on clinical outcome in patients with acute pancreatitis, based on a national administrative database.
abstract: OBJECTIVE
  This study aimed to investigate the relationship between hospital volume and clinical outcome in patients with acute pancreatitis, using a Japanese national administrative database.
  
  
  METHODS
  A total of 7007 patients with acute pancreatitis were referred to776 hospitals in Japan. Patient data were corrected according to the severity of acute pancreatitis to allow the comparison of risk-adjusted in-hospital mortality and length of stay in relation to hospital volume. Hospital volume was categorized based on the number of cases during the study period into low-volume (<10 cases), medium-volume (10-16 cases), and high-volume hospitals (HVHs, >16 cases).
  
  
  RESULTS
  Increased hospital volume was significantly associated with decreased relative risk of in-hospital mortality in both patients with mild and those with severe acute pancreatitis. The odds ratios for HVHs were 0.424 (95% confidence interval [CI], 0.228-0.787; P = 0.007) and 0.338 (95% CI, 0.138-0.826; P = 0.017), respectively. Hospital volume was also significantly associated with shorter length of stay in patients with mild acute pancreatitis. The unstandardized coefficient for HVHs was -0.978 days (95% CI, -1.909 to -0.048; P = 0.039).
  
  
  CONCLUSIONS
  This study demonstrated that hospital volume influences the clinical outcome in both patients with mild and those with severe acute pancreatitis.
authors.affiliation: Department of Preventive Medicine and Community Health, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan. amurata@med.uoeh-u.ac.jp
authors.forename: Atsuhiko
authors.initials: A
authors.lastname: Murata
authors.forename: Shinya
authors.initials: S
authors.lastname: Matsuda
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Mayumi
authors.forename: Masamichi
authors.initials: M
authors.lastname: Yokoe
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Kuwabara
authors.forename: Yukako
authors.initials: Y
authors.lastname: Ichimiya
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Fujino
authors.forename: Tatsuhiko
authors.initials: T
authors.lastname: Kubo
authors.forename: Kenji
authors.initials: K
authors.lastname: Fujimori
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Horiguchi
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D016009:Chi-Square Distribution; D019992:Databases as Topic; D005260:Female; D017052:Hospital Mortality; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007902:Length of Stay; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010043:Outcome and Process Assessment, Health Care / Q000706:statistics & numerical data*; D010195:Pancreatitis / Q000175:diagnosis / Q000453:epidemiology / Q000401:mortality / Q000628:therapy*; D019984:Quality Indicators, Health Care / Q000706:statistics & numerical data*; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome