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- Xiaofeng Wang and Xinge Ji.
- Department of Quantitative Health Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH. Electronic address: wangx6@ccf.org.
- Chest. 2020 Jul 1; 158 (1S): S12-S20.
AbstractSample size determination is an essential step in planning a clinical study. It is critical to understand that different study designs need different methods of sample size estimation. Although there is a vast literature discussing sample size estimation, incorrect or improper formulas continue to be applied. This article reviews basic statistical concepts in sample size estimation, discusses statistical considerations in the choice of a sample size for randomized controlled trials and observational studies, and provides strategies for reducing sample size when planning a study. To assist clinical researchers in performing sample size calculations, we have developed an online calculator for common clinical study designs. The calculator is available at http://riskcalc.org:3838/samplesize/. Finally, we offer our recommendations on reporting sample size determination in clinical studies.Copyright © 2020 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.
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