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BMC Medical Research Methodology
Published in: BMC Medical Research Methodology 1/2013

Open Access 01-12-2013 | Correspondence

Selecting a sample size for studies with repeated measures

Authors: Yi Guo, Henrietta L Logan, Deborah H Glueck, Keith E Muller

Published in: BMC Medical Research Methodology | Issue 1/2013

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Abstract

Many researchers favor repeated measures designs because they allow the detection of within-person change over time and typically have higher statistical power than cross-sectional designs. However, the plethora of inputs needed for repeated measures designs can make sample size selection, a critical step in designing a successful study, difficult. Using a dental pain study as a driving example, we provide guidance for selecting an appropriate sample size for testing a time by treatment interaction for studies with repeated measures. We describe how to (1) gather the required inputs for the sample size calculation, (2) choose appropriate software to perform the calculation, and (3) address practical considerations such as missing data, multiple aims, and continuous covariates.
Appendix
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Metadata
Title
Selecting a sample size for studies with repeated measures
Authors
Yi Guo
Henrietta L Logan
Deborah H Glueck
Keith E Muller
Publication date
01-12-2013
Publisher
BioMed Central
Published in
BMC Medical Research Methodology / Issue 1/2013
Electronic ISSN: 1471-2288
DOI
https://doi.org/10.1186/1471-2288-13-100

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