This study applied a cost-effectiveness model to seven randomized trials. The model demonstrates the effect of design choices made in the planning stages of a clinical trial on the costs and benefits derived from conducting the trial. The study focused on one parameter used to calculate sample size: the minimum clinically important difference in event rates between control and experimental therapies. The study shows that the model can be operationalized to these trials. A computerized software package and manual has been developed to simplify the calculations. While there was some variation in the incremental cost-effectiveness ratios across the seven trials in this study, all ratios may be below the funding threshold. This analytical technique can be used to demonstrate explicitly the resource consequences of the design of randomized trials and perhaps to set funding priorities.