Feasibility of using administrative claims data for cost-effectiveness analysis of a clinical trial

This study was performed retrospectively to determine if Medicare claims data could be used to evaluate the cost effectiveness, from a payer perspective, of different radiation treatment schedules evaluated in a national clinical trial.

Medicare costs from all providers and all places of service were obtained from the Centers for Medicare & Medicaid Services for patients treated in the period 1992-1996 on Radiation Therapy Oncology Group 90-03, and combined with data on outcomes from the trial.

Of the 1,113 patients entered, Medicare cost data and clinical outcomes were available for 187 patients. Significant differences in tolerance of treatment and outcome were noted between patients with Medicare data included in the study and patients without Medicare data, and non-Medicare patients excluded from it. Ninety-five percent confidence ellipses on the incremental cost-effectiveness scatterplots crossed both axes, indicating non-significant differences in cost effectiveness between radiation treatment schedules.

Claims data permit estimation of cost effectiveness, but Medicare data provide inadequate representation of results applicable to patients from the general population.