Calculation of Sample Size in Clinical Trials |
Hyo Jin Lee, Yang Soo Kim, In Park |
Department of Orthopedic Surgery, Seoul St. Mary's Hospital Catholic University of Korea, Korea. kysoos@catholic.ac.kr |
임상 연구에서 연구 표본수의 산출 |
이효진·김양수·박박인 |
가톨릭대학교 의과대학 서울성모병원 정형외과 |
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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. |
Key Words:
Sample size; Statistica analysis; Significance; Power; Effect size |