To test concordance of the EEE power estimates with available study power, we used the Concordance correlation coefficient (CCC) [14]. The CCC evaluates the agreement of paired observations by measuring variation from the 45% line through the origin (the concordance line) and is used to validate the reproducibility of paired observations. It is also robust against samples from uniform and Poisson distributions even with small sample sizes. For each EEE estimate for power, we also computed percent power difference (PPD) as 100*(Power estimated by EEE – Power given in available simulation study), and also calculated its absolute value (APPD).
