Sample Size Determination in Randomised Controlled Clinical Trials: A Narrative Review

This article summarises efforts towards understanding the calculation of sample size determination in Randomised controlled Clinical Trials (RCTs). Readers would gain insight into the procedures behind sample size calculation in RCTs and its significance. Additionally, researchers, including residents, will learn to calculate sample sizes independently, aiding in their postgraduate thesis or dissertation work, especially for straightforward projects. The determination of sample size depends on various factors, several of which are discussed in this article. The concepts of biostatistics, which underpin sample size calculations and other statistical computations, are also elucidated. Examples are provided to illustrate how formula variations correspond to changes in influencing factors. Furthermore, a list of relevant software tools is included.