RANDOMIZED OBSERVATIONAL STUDIES ON THE ECONOMICS OF THERAPIES - BIOMETRICAL EXPERIENCE OF 2 TRIALS

Economic studies in medicine are intended to investigate costs, associ ated with a particular problem dealing with the indication, diagnosis or therapy, for instance, whether the high costs involved in a highly intensive or innovative therapy could be balanced by the eventual savi ngs made, due to the shorter periods of treatment. In such situations a randomized controlled trial is necessary to find out which therapy o r which therapeutical strategy is least expensive in the long run. Eco nomic studies do, however, present some specific problems. Making a li st of all the cost-relevant treatment items can be very laborious, but the use of flat rates and lump sums alone cannot lead to a complete c ost analysis. Often, costs between hospitals vary more than between tr eatment regimens. Early and sudden deaths incur low costs and may bias the results. Furthermore, costs are distributed with a long and heavy upper tail including extreme outliers. This does, in fact, complicate the estimation of the sample size. In this article, these problems ar e outlined and, with the help of the data obtained from two randomized economic trials in health care, solutions are proposed and discussed.