Abstract
Objectives
To describe a method using confidence intervals (CIs) to estimate the sample size
for a pilot randomized trial.
Study Design
Using one-sided CIs and the estimated effect size that would be sought in a large
trial, we calculated the sample size needed for pilot trials.
Results
Using an 80% one-sided CI, we estimated that a pilot trial should have at least 9%
of the sample size of the main planned trial.
Conclusion
Using the estimated effect size difference for the main trial and using a one-sided
CI, this allows us to calculate a sample size for a pilot trial, which will make its
results more useful than at present.
Keywords
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Article info
Publication history
Published online: November 29, 2012
Accepted:
September 5,
2012
Footnotes
Conflict of interest statement: We confirm that we have no conflict of interest.
Competing interests: Both authors have no competing interests.
Identification
Copyright
© 2013 Elsevier Inc. Published by Elsevier Inc. All rights reserved.
