Sample size determination for repeated measures design using G Power software |
Hyun Kang |
Department of Anesthesiology and Pain Medicine, Chung-Ang University College of Medicine, Seoul, Korea. roman00@naver.com |
Received: 8 October 2014 • Accepted: 19 December 2014 |
Abstract |
Repeated measures designs are widely used in the field of anesthesiology because they allow the detection of within-person change over time and provide a higher statistical power for detecting differences than a single measure design while reducing the costs and efforts to conduct a study. However, the complex process of calculating the sample size for repeated measures design requires profound statistical knowledge and also programming skills in some instances. In the present article, the author describes 1) the basic statistics for repeated measures design, 2) the explanation for G Power software, and 3) how to calculate the sample size using an example. |
Key Words:
G Power, Power calculation, Repeated measures design, Sample size determination, Sphericity |
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