Figure 4
Effect of variability of (A) EC50 or (B) maximal response on sample size for two consecutive sigmoidal dose–response transformations with various group mean differences. The difference between the simulation sample size estimates (n) and the theoretical sample size increases at a given group mean difference when greater variability is added to the maximal response parameter, with alpha and power held constant. (C) Effect of variability of maximal response on sample size for three consecutive sigmoidal dose–response transformations with various group mean differences. The difference between the simulation sample size estimates and the theoretical sample size increases at a given group mean difference when a third dose–response function is added to the simulation, with variability in the maximal response parameter.
