Sample size estimation: how many individuals should be studied?

  title={Sample size estimation: how many individuals should be studied?},
  author={John Eng},
  volume={227 2},
  • J. Eng
  • Published 1 May 2003
  • Education
  • Radiology
The number of individuals to include in a research study, the sample size of the study, is an important consideration in the design of many clinical studies. This article reviews the basic factors that determine an appropriate sample size and provides methods for its calculation in some simple, yet common, cases. Sample size is closely tied to statistical power, which is the ability of a study to enable detection of a statistically significant difference when there truly is one. A trade-off… 

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