| Title | A simple method for calculating power based on a prior trial. |
|---|---|
| Published in | Journal of Clinical Epidemiology, Vol. 63, p.992-997. ISSN 0895-4356. |
| Author | Borm, G.F.; Bloem, B.R.; Munneke, M.; Teerenstra, S. |
| Date | 2010 |
| Type | article |
| Abstract | OBJECTIVE: When an investigator wants to base the power of a planned clinical trial on the outcome of another trial, the latter study may not have been reported in sufficient detail to allow this. For example, when the outcome is a change from baseline, the power calculation requires the standard deviation of the difference, and it frequently happens that only the standard deviations of the baseline and the follow-up measurements are reported. Also when a complex analysis or an analysis with covariates is planned, the power calculation may be difficult or impossible. The objective was to develop a method to determine the power of a trial, based on minimal information from a previous (reference) trial. STUDY DESIGN AND SETTING: We investigated the power calculation for a range of statistical methods, including the t-test, analysis of covariance, analysis of variance, linear regression, logistic regression, Poisson regression, the Wilcoxon test, and the logrank test. RESULTS: A method to calculate the power of a trial solely based on the P-value or the confidence interval of the outcome of the reference study. CONCLUSION: A power calculation based on an earlier similar trial only requires its P-value. |
| Publication | http://repository.ubn.ru.nl/handle/2066/87370 |
| OpenURL | Search this publication in (your) library |
| Persistent Identifier | urn:nbn:nl:ui:22-2066/87370 |
| Metadata | XML |
| Repository | Radboud University Nijmegen |
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