Sample Size Estimation

Abstract

Sample size estimation is the process by which a researcher decides how many subjects to include in a given clinical trial. Sample size estimation is a critical part of the design of clinical trials, and, like all design issues, this must be addressed in the study protocol before the trial commences. However, discussion of this topic was intentionally delayed until this point in the book so that you could read the intervening chapters and acquire an understanding of important concepts, including statistical significance and clinical significance, before reading about sample size estimation. Addressing sample size estimation at this point also allows a whole (short) chapter to be dedicated to this topic, thereby acknowledging its importance in clinical research.

Deciding upon the sample size for a given clinical trial is a balancing act in which several factors need to be considered to achieve the balance desired by the sponsor.