Sample size estimation: How many individuals should be studied?

被引:538
作者
Eng, J [1 ]
机构
[1] Johns Hopkins Univ, Russell H Morgan Dept Radiol & Radiol Sci, Baltimore, MD 21287 USA
关键词
radiology and radiologists; research; statistical analysis;
D O I
10.1148/radiol.2272012051
中图分类号
R8 [特种医学]; R445 [影像诊断学];
学科分类号
1002 ; 100207 ; 1009 ;
摘要
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 I 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 exists between a feasible sample size and adequate statistical power. Strategies for reducing the necessary sample size while maintaining a reasonable power will also be discussed.
引用
收藏
页码:309 / 313
页数:5
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