Fig. 2

Steps involved in planning a confirmatory study. Highlighted (pink) aspects (v – vii) are discussed in more detail. Whereas other aspects (grey, (I – iii and viii—ix) are equally important, they are beyond the scope of this manuscript and are solely mentioned in the context of experimental design, standardization and/or sample size calculation. Highlighted in purple (iv) is the choice of participating study centers. Here, skills and expertise as well as training requirements are important selection criteria. Blue notes cannot be assigned to only one aspect, but need to be considered at different stages, e.g., sample size calculation as well as the analysis should be based on the experimental unit