Hands-on Guide to Sample Size Calculation in Medical Research Using EZR

Abstract

Sample size calculation is an important part of any medical research. The statistical analysis will provide valid inference only when the sample size is adequate enough to answer the research question. A small sample size may produce inconclusive results and too large sample size will waste the resources and could expose more participants than necessary. Hence the proper estimation of minimum required sample size for research is an important step in the design of any study. The present article gives an introduction to the various aspects of sample size estimation with hypothetical examples along with step-by-step illustration using EZR software.