Design and Analysis of Unit Cost Estimation Studies: How Many Hospital Diagnoses? How Many Countries?

Addresses three cost questions that commonly arise in multinational trials: (1) In countries where investigators plan to collect hospital unit cost estimates for a selected set of diagnoses, how should one estimate unit costs for the remaining diagnoses observed in the trial for which cost data were not collected? (2) For how many hospital diagnoses should estimates be obtained? (3) For how many countries should they be obtained? The authors used unit cost data collected in four western European countries and three relative value measures from the U.S. Medicare diagnosis-related group (DRG) payment system, finding that mean length of stay from the U.S. system is a good predictor of unit costs in four countries in Europe.