Design and analysis of unit cost estimation studies: How many hospital diagnoses? How many countries?

We evaluated three questions that commonly arise when unit costing exercises for multinational trials are conducted: (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? We addressed these questions using unit cost data collected in four western European countries and three relative value measures from the US Medicare diagnosis-related group (DRG) payment system. We found that the arithmetic mean length of stay from the US DRG payment system was a good predictor of unit costs in four countries in Europe. We also found that the imputation error decreased as the number of hospital diagnoses and countries sampled increased, but that the rate of reduction in error shrank. Finally, we found that - given the existence of a reliable method for cost imputation - from a pure information standpoint, it is better to obtain estimates for fewer hospital diagnoses from more countries than the reverse.

[1]  K. Schulman,et al.  Results of the Economic Evaluation of the FIRST Study: A Multinational Prospective Economic Evaluation , 1996, International Journal of Technology Assessment in Health Care.

[2]  H. Glick,et al.  Economic Evaluation of the Randomized Aldactone Evaluation Study (RALES): Treatment of Patients with Severe Heart Failure , 2004, Cardiovascular Drugs and Therapy.

[3]  R. Willke,et al.  Economic Analysis of Tirilazad Mesylate for Aneurysmal Subarachnoid Hemorrhage: Economic Evaluation of a Phase III Clinical Trial in Europe and Australia , 1998, International Journal of Technology Assessment in Health Care.

[4]  M. Johannesson,et al.  Cost effectiveness of simvastatin treatment to lower cholesterol levels in patients with coronary heart disease. Scandinavian Simvastatin Survival Study Group. , 1997, The New England journal of medicine.

[5]  R. Tretiak,et al.  Cost-effectiveness of simvastatin in the secondary prevention of coronary artery disease in Canada. , 1997, CMAJ : Canadian Medical Association journal = journal de l'Association medicale canadienne.

[6]  Erry,et al.  Cost effectiveness of thrombolytic therapy with tissue plasminogen activator as compared with streptokinase for acute myocardial infarction. , 1995, The New England journal of medicine.

[7]  P Carlsson,et al.  Resource costing for multinational neurologic clinical trials: methods and results. , 1998, Health economics.

[8]  B. Kinosian,et al.  Costs and effects of enalapril therapy in patients with symptomatic heart failure: an economic analysis of the Studies of Left Ventricular Dysfunction (SOLVD) Treatment Trial. , 1995, Journal of cardiac failure.

[9]  J. Mauskopf,et al.  Cost-effectiveness model of adjunctive lamotrigine for the treatment of epilepsy , 1998, Neurology.

[10]  H. Glick,et al.  Prospective economic evaluation accompanying a trial of GM-CSF/IL-3 in patients undergoing autologous bone marrow transplantation for Hodgkin’s and non-Hodgkin’s lymphoma , 1998, Bone Marrow Transplantation.

[11]  C. Legendre,et al.  VALACICLOVIR PROPHYLAXIS OF CYTOMEGALOVIRUS INFECTION AND DISEASE IN RENAL TRANSPLANTATION: AN ECONOMIC EVALUATION , 2000, Transplantation.