Considerations on the statistical design of the ATMI study

Abstract

The ATMI study of prevention of mediastinitis after cardiac surgery uses the total amount of therapeutic interventions measured by the TISS-28 score as the primary endpoint. The study is designed as an adaptive group- sequential plan with three sequences, as experiences with the TISS-28 in cardiac intensive care units are scarce. According to the Bauer-Kohne method the sample sizes of the second and third sequences can be calculated in a data-driven manner after the results of the previous interim analyses are available. Thus the first trial phase can be considered as an internal pilot study.