title: Comparison of hospital costing methods in an economic evaluation of a multinational clinical trial.
abstract: OBJECTIVE
  To develop and evaluate strategies for estimating hospitalization costs in multinational clinical trials.
  
  
  METHODS
  Hospital cost estimates for eleven diagnoses were collected from twelve countries participating in a trial of therapies for congestive heart failure. Estimates were combined with U.S.-based diagnosis-related group weights to compute country-specific unit cost estimates for all reasons for hospitalization. Variations of hospital costing methods were developed. The unit cost method assigns a country-specific unit cost estimate to each hospitalization. The other methods adjust for length of stay using a daily cost (DC) estimate for each diagnosis, based on either the mean length of stay (DC-mean method) or the median length of stay (DC-median method) for each diagnosis in each country. Additional modifications were explored through adjustment of the distribution of daily costs incurred during a hospital stay.
  
  
  RESULTS
  The mean cost for all hospitalizations was dollars 10,242 (SD, 10,042) using the unit cost method, dollars 10,242 (SD, 12,760) using the standard DC-mean method, and dollars 13,967 (SD, 18,762) using the standard DC-median method. In comparisons of costs for all 5,486 hospitalizations incurred by a subset of 2,352 patients in the trial, the unit cost method provided 92% power to detect a dollars 1,000 cost difference. The standard DC-mean method provided 76% power, and the standard DC-median method provided 44% power.
  
  
  CONCLUSIONS
  Hospital costing methods that adjust for differences in length of stay require a significantly larger sample to attain comparable statistical power as methods that assign unadjusted unit cost estimates to hospitalization events.
authors.affiliation: Center for Clinical and Genetic Economics, Duke Clinical Research Institute, Duke University Medical Center, Durham, NC 17715, USA. shelby.reed@duke.edu
authors.forename: Shelby D
authors.initials: SD
authors.lastname: Reed
authors.forename: Joëlle Y
authors.initials: JY
authors.lastname: Friedman
authors.forename: Ari
authors.initials: A
authors.lastname: Gnanasakthy
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Schulman
mesh_terms: D002986:Clinical Trials as Topic / Q000191:economics*; D003365:Costs and Cost Analysis / Q000379:methods; D019049:Developed Countries; D003953:Diagnosis-Related Groups; D006333:Heart Failure / Q000191:economics / Q000628:therapy; D017721:Hospital Costs / Q000706:statistics & numerical data*; D006760:Hospitalization / Q000191:economics* / Q000706:statistics & numerical data; D006801:Humans; D038622:Internationality; D007902:Length of Stay; D014481:United States