Post hoc power analysis was conducted to assess the statistical power of the regression models used in the study .Most of the regression models, with 13 or 6 variables, reached an adequate level of statistical power ranging between 0.81 and 0.99 .However, two models did not reach an adequate level of power. The models predicting PDQ39-PS from BBS and confounding variables had power values of 0.36 and 0.22, respectively [1]..