[Conducting a cost-effectiveness trial in oncology: justification and method]

The occurrence of scarce financial resources and the aim of an adequate allocation of available budgets for public community induce to conduct trials where primary endpoint could be a medico-economic criterion. In oncology, the emergent place of "stop and go" strategy and or the diminution of chemotherapy administration induce initially to demonstrate non-inferiority of these strategies for efficacy. Another underlying objective for these trials could be also to demonstrate the medico-economic superiority of these strategies. In this context, medico-economic trials using cost and efficacy composite endpoint as primary endpoint for therapeutical strategies comparison could be an interesting alternative of classical clinical trials using only an efficacy endpoint. Based on a review, the aim of this paper is to focus about design of medico-economic trials: objectives, methods and sample size calculations.