Effect of hospital volume on clinical outcome in patients with acute pancreatitis, based on a national administrative database

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.