title: Hospital resource utilization for primary and revision total hip arthroplasty.
abstract: BACKGROUND
  Previous reports have suggested that hospital resource utilization for revision total hip arthroplasty is substantially higher than that for primary total hip arthroplasty. However, current United States Medicare hospital-reimbursement policy does not distinguish between the two procedures. The purpose of this study was to compare primary and revision total hip arthroplasties with regard to actual hospital resource utilization and to identify clinical and demographic factors that are predictive of higher resource utilization associated with these procedures.
  
  
  METHODS
  We evaluated the clinical, demographic, and economic data associated with 491 consecutive unilateral primary or revision total hip arthroplasties performed by two surgeons at a single institution between January 2000 and December 2002. The distributions of various demographic, clinical, and utilization characteristics were compared between the two types of arthroplasty procedures, and multivariable linear regression techniques were used to determine independent patient characteristics that were predictive of higher costs for both the primary and the revision procedures.
  
  
  RESULTS
  The mean total hospital cost was $31,341 for the revision procedures compared with $24,170 for the primary procedures (p < 0.0001). The mean operative time was 41% longer for the revisions than for the primary procedures (4.5 hours compared with 3.2 hours, p < 0.0001), the mean estimated blood loss was 160% higher (1348 mL compared with 518 mL, p < 0.0001), the mean complication rate was 32% higher (29% compared with 22%, p = 0.072), and the mean length of the hospital stay was 16% longer (6.5 days compared with 5.6 days, p = 0.0005). A higher severity-of-illness score (a measure of preoperative medical health) was predictive of higher resource utilization for both primary and revision arthroplasty even after adjustment for other factors. Preoperative femoral and ace-tabular bone loss and a diagnosis of periprosthetic fracture were predictive of higher resource utilization associated with revision procedures.
  
  
  CONCLUSIONS
  At one institution, hospital resource utilization for revision total hip arthroplasty was found to be significantly higher than that for primary arthroplasty. This information is not reflected by current United States Medicare hospital reimbursement, which is the same for all lower-extremity arthroplasty procedures, regardless of the diagnosis, the complexity of the procedure, or the patient's baseline medical health. If these findings are generalizable to other institutions, appropriate reimbursement formulas should be developed to accurately reflect the true costs of caring for patients with a failed total hip arthroplasty.
authors.affiliation: Department of Orthopaedic Surgery, University of California, San Francisco, 500 Parnassus Avenue, MU 320W, San Francisco, CA 94143-0728, USA. bozick@orthosurg.ucsf.edu
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Bozic
authors.forename: Patricia
authors.initials: P
authors.lastname: Katz
authors.forename: Miriam
authors.initials: M
authors.lastname: Cisternas
authors.forename: Linda
authors.initials: L
authors.lastname: Ono
authors.forename: Michael D
authors.initials: MD
authors.lastname: Ries
authors.forename: Jonathan
authors.initials: J
authors.lastname: Showstack
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000191:economics*; D016063:Blood Loss, Surgical; D005260:Female; D006295:Health Resources / Q000706:statistics & numerical data*; D006760:Hospitalization / Q000191:economics / Q000706:statistics & numerical data; D006801:Humans; D007902:Length of Stay / Q000191:economics; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012051:Reimbursement Mechanisms; D012086:Reoperation; D013997:Time Factors; D014481:United States