Clin Should Elbow.
2013 Jun;16(1):53-57.
Calculation of Sample Size in Clinical Trials
- Affiliations
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- 1Department of Orthopedic Surgery, Seoul St. Mary's Hospital Catholic University of Korea, Korea. kysoos@catholic.ac.kr
Abstract
- PURPOSE
This review aims to explain the definition and basic principle of statistical analysis and to clarify statistical issues related to the sample size calculation.
MATERIALS AND METHODS
Many formulas are available that can be applied for different types of data and study design.
RESULTS
The sample size is the number of patients or other experimental units that need to be calculated prior to the study. Determining the appropriate sample size is required to answer the research question.
CONCLUSION
Caution is needed when applying formula for the calculation of the sample size, as it is sensitive to error and even small differences in selected parameters can lead to large differences in the sample size.