Unfortunately, it seems that the issue of post-hoc power / “observed” power just won’t die. Apologies to those that follow me on Twitter who are already aware of this, as I’ve been hammering this article for the last day or two, but a group of surgeons have been promoting the nonsensical idea that all studies which report negative results should include a post-hoc power calculation using the observed effect size, an idea which the statistical community has written a number of articles about over the years:
I have provided a lengthy reply at PubPeer:
https://pubpeer.com/publications/4399282A80691D9421B497E8316CF6#2
If you read this article and are as troubled as I am, I encourage you to also leave a comment at PubPeer. This article is wrong about nearly everything it says (the initial premise that “absence of evidence is not evidence of absence” and giving more thought to power/sample size, I am fine with; however, the entire applied portion is wrong as well as the subsequent recommendation that all studies be reported with an “observed” power, for reasons laid out in my PubPeer comments).
My PubPeer reply references several excellent resources which you may be interested in should you ever be pushed on this issue of “observed” power in a completed study: