title: Hospital volume, length of stay, and readmission rates in high-risk surgery.
abstract: OBJECTIVE
  Aimed at reducing surgical deaths, several recent initiatives have attempted to establish volume-based referral strategies in high-risk surgery. Although payers are leading the most visible of these efforts, it is unknown whether volume standards will also reduce resource use.
  
  
  METHODS
  We studied postoperative length of stay and 30-day readmission rate after 14 cardiovascular and cancer procedures using the 1994-1999 national Medicare database (total n = 2.5 million). We used regression techniques to examine the relationship between length of stay, 30-day readmission, and hospital volume, adjusting for age, gender, race, comorbidity score, admission acuity, and mean social security income.
  
  
  RESULTS
  Mean postoperative length of stay ranged from 3.4 days (carotid endarterectomy) to 19.6 days (esophagectomy). There was no consistent relationship between volume and mean length of stay; it significantly increased across volume strata for 7 of the 14 procedures and significantly decreased across volume strata for the other 7. Mean length of stay at very-low-volume and very-high-volume hospitals differed by more than 1 day for 6 procedures. Of these, the mean length of stay was shorter in high-volume hospitals for 3 procedures (pancreatic resection, esophagectomy, cystectomy), but longer for other procedures (aortic and mitral valve replacement, gastrectomy). The 30-day readmission rate also varied widely by procedure, ranging from 9.9% (nephrectomy) to 22.2% (mitral valve replacement). However, volume was not related to 30-day readmission rate with any procedure.
  
  
  CONCLUSIONS
  Although hospital volume may be an important predictor of operative mortality, it is not associated with resource use as reflected by length of stay or readmission rates.
authors.affiliation: Department of Veterans Affairs Medical Center, White River Junction, VT 05009, USA. philip.goodney@hitchcock.org
authors.forename: Philip P
authors.initials: PP
authors.lastname: Goodney
authors.forename: Therese A
authors.initials: TA
authors.lastname: Stukel
authors.forename: F Lee
authors.initials: FL
authors.lastname: Lucas
authors.forename: Emily V A
authors.initials: EV
authors.lastname: Finlayson
authors.forename: John D
authors.initials: JD
authors.lastname: Birkmeyer
mesh_terms: D002318:Cardiovascular Diseases / Q000601:surgery; D013504:Cardiovascular Surgical Procedures / Q000706:statistics & numerical data; D003196:Computer Graphics; D006751:Hospital Information Systems; D006801:Humans; D007902:Length of Stay / Q000706:statistics & numerical data*; D016014:Linear Models; D016015:Logistic Models; D006278:Medicare; D009369:Neoplasms / Q000601:surgery; D010359:Patient Readmission / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012495:San Francisco; D013514:Surgical Procedures, Operative / Q000706:statistics & numerical data*