title: Effect of meeting Leapfrog volume thresholds on complication rates following complex surgical procedures.
abstract: BACKGROUND
  There is limited published data on the relationship between hospital volume and postoperative complications. The objectives of the current study are to examine the association between hospital volume and complications and also to examine the association between complications and in-hospital mortality following 5 complex surgical procedures.
  
  
  METHODS
  The Nationwide Inpatient Sample for years 2000 to 2003 was used. Patients who underwent coronary artery bypass graft (CABG), percutaneous coronary intervention (PCI), elective abdominal aortic aneurysm repair (AAA), pancreatectomy (PAN), and esophagectomy (ESO) as primary procedures were selected. Hospital volumes were calculated as suggested by the Leapfrog Group evidence-based hospital referral criteria. The association between hospital volume and complications were examined by multivariable logistic regression analyses, adjusting for patient and hospital characteristics.
  
  
  RESULTS
  A total of 261551 CABG, 573072 PCI, 35104 AAA, 4931 PAN, and 2473 ESO procedures were selected for analysis. A total of 580 hospitals performed the CABG procedures during the study period in this dataset. The corresponding numbers of hospitals for PCI, AAA, PAN, and ESO were 714, 1207, 758, and 555 respectively. In-hospital complication rates following CABG, PCI, AAA, PAN, and ESO were 26.45%, 6.74%, 23.81%, 39.28%, and 46.30%, respectively. High-volume hospitals for all the procedures were associated with lower odds for in-hospital mortality when compared with low-volume hospitals (P < 0.05). High-volume hospitals were associated with significantly lower odds for at least one complication following 3 of the 5 procedures (PCI, AAA, and PAN) and specifically for significantly lower odds for respiratory complications following CABG, AAA, and PAN, digestive complications following PAN, hemorrhage/hematoma complications following PCI, and septicemia following PCI and PAN when compared with low-volume hospitals (P < 0.05).
  
  
  CONCLUSIONS
  Lower mortality rates in high-volume hospitals can be partly, though not completely, attributed to lower complication rates. Future studies must focus on identifying other potential pathways for reduced mortality in high-volume hospitals.
authors.affiliation: Department of Health Management and Policy, College of Public Health, The University of Iowa, Iowa City, IA, USA. VA15@hsdm.harvard.edu
authors.forename: Veerasathpurush
authors.initials: V
authors.lastname: Allareddy
authors.forename: Marcia M
authors.initials: MM
authors.lastname: Ward
authors.forename: Veerajalandhar
authors.initials: V
authors.lastname: Allareddy
authors.forename: Badrinath R
authors.initials: BR
authors.lastname: Konety
mesh_terms: D000368:Aged; D005260:Female; D006742:Hospital Bed Capacity / Q000706:statistics & numerical data*; D017052:Hospital Mortality / Q000639:trends*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology*