title: Hospital costs by cost center of inpatient hospitalization for medicare patients undergoing major abdominal surgery.
abstract: BACKGROUND
  This study aims to describe the magnitude of hospital costs among patients undergoing elective colectomy, cholecystectomy, and pancreatectomy, determine whether these costs relate as expected to duration of care, patient case-mix severity and comorbidities, and whether risk-adjusted costs vary significantly by hospital. Correctly estimating the cost of production of surgical care may help decision makers design mechanisms to improve the efficiency of surgical care.
  
  
  METHODS
  Patient data from 202 hospitals in the ACS-NSQIP were linked to Medicare inpatient claims. Patient charges were mapped to cost center cost-to-charge ratios in the Medicare cost reports to estimate costs. The association of patient case-mix severity and comorbidities with cost was analyzed using mixed effects multivariate regression. Cost variation among hospitals was quantified by estimating risk-adjusted hospital cost ratios and 95% confidence intervals from the mixed effects multivariate regression.
  
  
  RESULTS
  There were 21,923 patients from 202 hospitals who underwent an elective colectomy (n = 13,945), cholecystectomy (n = 5,569), or pancreatectomy (n = 2,409). Median cost was lowest for cholecystectomy ($15,651) and highest for pancreatectomy ($37,745). Room and board costs accounted for the largest proportion (49%) of costs and were correlated with length of stay, R = 0.89, p < 0.001. The patient case-mix severity and comorbidity variables most associated with cost were American Society of Anesthesiologists (ASA) class IV (estimate 1.72, 95% CI 1.57 to 1.87) and fully dependent functional status (estimate 1.63, 95% CI 1.53 to 1.74). After risk-adjustment, 66 hospitals had significantly lower costs than the average hospital and 57 hospitals had significantly higher costs.
  
  
  CONCLUSIONS
  The hospital costs estimates appear to be consistent with clinical expectations of hospital resource use and differ significantly among 202 hospitals after risk-adjustment for preoperative patient characteristics and procedure type.
authors.affiliation: Icahn School of Medicine at Mount Sinai Medical Center, NY, NY; David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA. Electronic address: as013j@gmail.com.
authors.forename: Anne M
authors.initials: AM
authors.lastname: Stey
authors.affiliation: David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA; RAND Corporation, Santa Monica, CA.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Brook
authors.affiliation: Fielding School of Public Health, University of California Los Angeles, Los Angeles, CA.
authors.forename: Jack
authors.initials: J
authors.lastname: Needleman
authors.affiliation: American College of Surgeons, Chicago, IL; Washington University in Saint Louis Department of Surgery, Olin Business School, and Center for Health Policy; St Louis VA Medical Center; BJC Healthcare Saint Louis, St Louis, MO.
authors.forename: Bruce L
authors.initials: BL
authors.lastname: Hall
authors.affiliation: David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA.
authors.forename: David S
authors.initials: DS
authors.lastname: Zingmond
authors.affiliation: David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA.
authors.forename: Elise H
authors.initials: EH
authors.lastname: Lawson
authors.affiliation: David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA; American College of Surgeons, Chicago, IL.
authors.forename: Clifford Y
authors.initials: CY
authors.lastname: Ko
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002763:Cholecystectomy / Q000191:economics*; D003082:Colectomy / Q000191:economics*; D017558:Elective Surgical Procedures / Q000191:economics*; D005260:Female; D017721:Hospital Costs / Q000706:statistics & numerical data*; D006760:Hospitalization / Q000191:economics*; D006801:Humans; D016018:Least-Squares Analysis; D008297:Male; D006278:Medicare / Q000191:economics*; D015999:Multivariate Analysis; D010180:Pancreatectomy / Q000191:economics*; D020379:Risk Adjustment; D014481:United States