Statistical power is a useful but often misunderstood concept. Briefly, it represents the probability of rejecting a null hypothesis under some assumed conditions of a prospective experiment (distribution of the study outcome, planned sample size, and prespecified significance level to be used in the analysis). Most generally, we compute statistical power while planning comparative-effectiveness trials to ensure that the study will be large enough to conclude that an effect is present, if a meaningful effect truly exists.
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- Is the power threshold of 0.8 applicable to surgical science? Empowering the underpowered study.J Surg Res. 2019; 241: 235-239
- The use of predicted confidence intervals when planning experiments and the misuse of power when interpreting results.Ann Intern Med. 1994; 121: 200-206
- The abuse of power: the pervasive fallacy of power calculations for data analysis.Am Stat. 2001; 55: 19-24
- Some practical guidelines for effective sample size determination.Am Stat. 2001; 55: 187-193
- Post hoc power analysis: an idea whose time has passed?.Pharmacotherapy. 2001; 21: 405-409
- Post hoc power, observed power, A priori power, retrospective power, prospective power, achieved power: sorting out appropriate uses of statistical power analyses.Commun Methods Meas. 2007; 1: 291-299
- Observed power, and what to do if your editor asks for post-hoc power analyses.(Available at:)http://daniellakens.blogspot.com/2014/12/observed-power-and-what-to-do-if-your.htmlDate: 2014Date accessed: September 23, 2019
Published online: August 16, 2020
Accepted: October 1, 2019
Received: September 30, 2019
Authors' contributions: the sole author conceived, wrote, and submitted the article.
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