title: Case mix-adjusted cost of colectomy at low-, middle-, and high-volume academic centers.
abstract: Efforts to regionalize surgery based on thresholds in procedure volume may have consequences on the cost of health care delivery. This study aims to delineate the relationship between hospital volume, case mix, and variability in the cost of operative intervention using colectomy as the model.
  
  
  
  All patients undergoing colectomy (n = 90,583) at 183 academic hospitals from 2009-2012 in The University HealthSystems Consortium Database were studied. Patient and procedure details were used to generate a case mix-adjusted predictive model of total direct costs. Observed to expected costs for each center were evaluated between centers based on overall procedure volume.
  
  
  
  Patient and procedure characteristics were significantly different between volume tertiles. Observed costs at high-volume centers were less than at middle- and low-volume centers. According to our predictive model, high-volume centers cared for a less expensive case mix than middle- and low-volume centers ($12,786 vs $13,236 and $14,497, P < .01). Our predictive model accounted for 44% of the variation in costs. Overall efficiency (standardized observed to expected costs) was greatest at high-volume centers compared to middle- and low-volume tertiles (z score -0.16 vs 0.02 and -0.07, P < .01).
  
  
  
  Hospital costs and cost efficiency after an elective colectomy varies significantly between centers and may be attributed partially to the patient differences at those centers. These data demonstrate that a significant proportion of the cost variation is due to a distinct case mix at low-volume centers, which may lead to perceived poor performance at these centers.
authors.affiliation: Cincinnati Research in Outcomes and Safety in Surgery, Department of Surgery, University of Cincinnati School of Medicine, Cincinnati, OH.
authors.forename: Alex L
authors.initials: AL
authors.lastname: Chang
authors.affiliation: Cincinnati Research in Outcomes and Safety in Surgery, Department of Surgery, University of Cincinnati School of Medicine, Cincinnati, OH.
authors.forename: Young
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Cincinnati Research in Outcomes and Safety in Surgery, Department of Surgery, University of Cincinnati School of Medicine, Cincinnati, OH.
authors.forename: Audrey E
authors.initials: AE
authors.lastname: Ertel
authors.affiliation: Cincinnati Research in Outcomes and Safety in Surgery, Department of Surgery, University of Cincinnati School of Medicine, Cincinnati, OH.
authors.forename: Richard S
authors.initials: RS
authors.lastname: Hoehn
authors.affiliation: Cincinnati Research in Outcomes and Safety in Surgery, Department of Surgery, University of Cincinnati School of Medicine, Cincinnati, OH.
authors.forename: Koffi
authors.initials: K
authors.lastname: Wima
authors.affiliation: Cincinnati Research in Outcomes and Safety in Surgery, Department of Surgery, University of Cincinnati School of Medicine, Cincinnati, OH.
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Abbott
authors.affiliation: Cincinnati Research in Outcomes and Safety in Surgery, Department of Surgery, University of Cincinnati School of Medicine, Cincinnati, OH. Electronic address: Shimul.shah@uc.edu.
authors.forename: Shimul A
authors.initials: SA
authors.lastname: Shah
mesh_terms: D000046:Academic Medical Centers; D000368:Aged; D003082:Colectomy / Q000191:economics*; D003108:Colonic Diseases / Q000453:epidemiology / Q000601:surgery*; D003953:Diagnosis-Related Groups; D005260:Female; D017721:Hospital Costs; D061847:Hospitals, High-Volume; D061846:Hospitals, Low-Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D014481:United States