In a 2013 review article in Nature Neuroscience, Button et al. Power failure: why small sample size undermines the reliability of neuroscience, it was stated that:
the average statistical power of studies in the neurosciences is very low
They searched for meta-analyses, calculated the post-hoc power in each one of them, and combined the results by taking the median post-hoc power. The median was 20%. I just don't get it. Post-hoc power is always inherently associated with the achieved p-values. Isn't it the same as to write that median p-value was something like ~0.3 which corresponds to the post-hoc power of 20%?
So basically how does this result undermine the quality of research in neurosciences? It seems that they have been publishing studies with a lot of non-significant p-values.
This review is a Nature Neuroscience study with very famous authors, so I think my interpretation is more likely flawed.
EDIT: I would see some point if they included only studies with nominal significance. In that case the median power would tell the median replication probability of significant findings.