title: Volume-outcome relationship in rectal cancer surgery: a new perspective.
abstract: OBJECTIVE
  Numerous studies on the volume-outcome relationships in rectal cancer surgery have assessed surgical mortality. However, little is known about the association between hospital/surgeon volumes and postoperative complications, including anastomotic leakage and infection, following rectal cancer surgery.
  
  
  METHODS
  Using a web-based patient registration system, data were collected on inpatients who underwent rectal cancer surgery between November 1, 2006 and February 28, 2007 in Japan. Using multivariate analyses, intraoperative blood loss, postoperative complications and length of stay were independently compared against the provider volumes and covariates.
  
  
  RESULTS
  No significant association was identified between the blood loss and hospital volume, while surgeons with the highest volume (> or =500 procedures) were likely to demonstrate a reduced blood loss (odds ratio, 0.67; 95% confidence interval, 0.46-0.99; P = 0.043). No significant relationship was found between the incidence of postoperative complications and the provider volume. A higher hospital volume significantly decreased the length of stay (hazard ratio, 1.41; 95% confidence interval, 1.23-1.62; P < 0.01), but the surgeon volume was not associated with the length of hospital stay.
  
  
  CONCLUSIONS
  The present study did not find any significant relationship between the volume and postoperative complications. These results do not support the effectiveness of regionalizing rectal cancer surgery to high-volume centers, at least in the Japanese clinical setting.
authors.affiliation: Department of Health Management and Policy, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Yasunaga
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Matsuyama
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Ohe
mesh_terms: D000368:Aged; D016063:Blood Loss, Surgical / Q000706:statistics & numerical data*; D002983:Clinical Competence; D005260:Female; D006801:Humans; D020407:Internet; D007564:Japan; D007902:Length of Stay; D008297:Male; D015999:Multivariate Analysis; D016017:Odds Ratio; D011183:Postoperative Complications / Q000453:epidemiology; D012004:Rectal Neoplasms / Q000601:surgery*; D012042:Registries; D013503:Surgery Department, Hospital / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D016526:Workload / Q000706:statistics & numerical data*