title: The impact of hospital volume on postoperative complications following robot-assisted partial nephrectomy.
abstract: OBJECTIVE
  We sought to evaluate the relationship between hospital volume and postoperative complications following robot-assisted partial nephrectomy (RAPN) using the Nationwide Inpatient Sample.
  
  
  METHODS
  We identified patients undergoing RAPN between 2009 and 2011. Hospitals were divided into volume-based tertiles for each year (high, medium, low). Descriptive analyses were performed using Pearson's chi-squared and Student's t-test. Multivariable logistic regression assessed the association between hospital volume and postoperative complications, adjusting for age, gender, hospital region, type of hospital, primary payer, comorbidities, and kidney cancer.
  
  
  RESULTS
  We identified 17,583 cases from 323 hospitals, of which 112 were low volume, 112 medium volume, and 99 high volume. 13,645 (78%) cases were performed at high-volume institutions. Eleven percent of patients developed an in-hospital postoperative complication, with 15% at low-volume, 12% at medium-volume, and 10% at high-volume hospitals (p=0.071). In addition, blood transfusion was less common at high-volume hospitals (p=0.015). On multivariable logistic regression, high-volume hospitals had 42% decreased odds of postoperative in-hospital complications (95% confidence interval 0.37-0.90; p=0.016). Complications were associated with a $4500 increase in hospital costs.
  
  
  CONCLUSIONS
  High-volume hospitals are associated with decreased blood transfusions and complications. With the recognition that high-volume RAPN hospitals are independently associated with improved clinical outcomes, further studies should be performed to determine the role of the hospital and surgeon volume thresholds in the performance of RAPN.
authors.affiliation: Department of Urology, Indiana University School of Medicine Indianapolis , Indiana.
authors.forename: M Francesca
authors.initials: MF
authors.lastname: Monn
authors.forename: Clinton D
authors.initials: CD
authors.lastname: Bahler
authors.forename: Chandra K
authors.initials: CK
authors.lastname: Flack
authors.forename: Hitesh T
authors.initials: HT
authors.lastname: Dube
authors.forename: Chandru P
authors.initials: CP
authors.lastname: Sundaram
mesh_terms: D000328:Adult; D000368:Aged; D016063:Blood Loss, Surgical; D001803:Blood Transfusion / Q000706:statistics & numerical data; D005260:Female; D017721:Hospital Costs; D006761:Hospitals; D061847:Hospitals, High-Volume / Q000706:statistics & numerical data*; D061846:Hospitals, Low-Volume / Q000706:statistics & numerical data*; D006801:Humans; D007674:Kidney Diseases / Q000601:surgery*; D007680:Kidney Neoplasms / Q000601:surgery; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009392:Nephrectomy; D011183:Postoperative Complications / Q000453:epidemiology*; D065287:Robotic Surgical Procedures