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A note on sample size calculation for mean comparisons based on noncentral t-statistics.

Shein-Chung Chow·Jun Shao·Hansheng Wang
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Abstract

One-sample and two-sample t-tests are commonly used in analyzing data from clinical trials in comparing mean responses from two drug products. During the planning stage of a clinical study, a crucial step is the sample size calculation, i.e., the determination of the number of subjects (patients) needed to achieve a desired power (e.g., 80%) for detecting a clinically meaningful difference in the mean drug responses. Based on noncentral t-distributions, we derive some sample size calculation formulas for testing equality, testing therapeutic noninferiority/superiority, and testing therapeutic equivalence, under the popular one-sample design, two-sample parallel design, and two-sample crossover design. Useful tables are constructed and some examples are given for illustration.

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Shein-Chung Chow, Jun Shao, Hansheng Wang. 2002. A note on sample size calculation for mean comparisons based on noncentral t-statistics.. https://doi.org/10.1081/bip-120016229

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