Basics of statistics-3: Sample size calculation – (i)

Introduction: From a practicing oncologist's perspective, sample size calculation is a very intriguing aspect of medical statistics. Methods: Basic aspects of sample size calculation in relevant case scenarios are discussed. Results: The formulae are illustrated with examples for easier understanding. Discussion: This article is a brief account of sample size calculation methods in different clinical research scenarios. The derivation of formulae is beyond the scope of this article. The discussion is kept simple by illustrations matching real life studies. More complex methods will be discussed in the next session of this series.