Dear all, 

I am preparing an analysis plan for a mega-analysis (meta-analysis with de-identified individual participant data). I have been advised to include an a priori power analysis to calculate the required sample size per group to achieve 80% power using the G*Power power analysis tool.

My question is - can I use SDM estimates, reported in a previous meta-analysis, as inputs in this power analysis tool? Can they be used in place of the usual Cohen's d? Are SDM estimates equivalent to a Cohen'd effect size (i.e. small (d = 0.2), medium (d = 0.5), and large (d = 0.8)?


Many thanks for your help with this matter!

Kind regards,
Sally