Skip to main content

Sample Size Estimation for Trials and Other Two Group Comparisons

By: , & Published: 2020 | Product: SAGE Research Methods Cases: Medicine and Health
+- LessMore information
Search form
No results
Not Found
Download Case PDF


When an investigator is designing a study to compare two groups with a continuous outcome, an essential step is the calculation of sample sizes that will allow a reasonable chance (power) of detecting a predetermined target difference (effect size), if it truly exists, at a given level of statistical significance. Four key components are required to facilitate a suitable sample size calculation. These are the target difference or effect size, the standard deviation of the outcome, and the Type I and Type II errors. This case study will illustrate the process and methods for determining the required sample size using a real case study as an example—the SELF randomized controlled trial to compare a self-managed single exercise program versus usual physiotherapy treatment for rotator cuff tendinopathy.

Looks like you do not have access to this content.

Copy and paste the following HTML into your website