Featured ArticleStatistical power and sample size calculations: A primer for pediatric surgeons☆,☆☆
Section snippets
Methods
We present a practical 5-step approach for the pediatric surgeon to determine the appropriate sample sizes needed to detect clinically and scientifically meaningful results based on sufficient statistical power. These steps can be applied to any prospective or retrospective research study scenario regardless of the nature of the data. The 5 steps are:
- 1.
Define the outcome variable of interest and comparison groups and formulate the clinical or scientific hypothesis. The outcome of interest may be
Discussion
We have demonstrated how to perform statistical power and sample size calculations with our 5-step approach using examples in pediatric surgery. Regardless of the research study, the nature of the outcome or exposure data, or the study design, our 5-step approach can be applied to perform power calculations correctly to determine the minimum required sample sizes to ensure sufficient power and meaningful interpretation of the study data.
It may be challenging to obtain sample sizes as large as
Conclusions
A properly performed and described power and sample size calculation improves the quality of manuscripts submitted to surgical journals, IRB proposals, and grant applications. The clinical hypotheses and the nature of the data guide the appropriate statistical test to be used in sample size calculations. Our article can be utilized as a practical guide for pediatric surgeons when designing a clinical study or laboratory investigation to ensure that the sample sizes will provide the sufficient
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