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

Journal Article (Journal Article)

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.

Full Text

Duke Authors

Cited Authors

  • Chow, S-C; Shao, J; Wang, H

Published Date

  • November 2002

Published In

Volume / Issue

  • 12 / 4

Start / End Page

  • 441 - 456

PubMed ID

  • 12477068

International Standard Serial Number (ISSN)

  • 1054-3406

Digital Object Identifier (DOI)

  • 10.1081/BIP-120016229


  • eng

Conference Location

  • England