Document Detail

Power of testing proportions in small two-sample studies when sample sizes are equal.
MedLine Citation:
PMID:  8516594     Owner:  NLM     Status:  MEDLINE    
In planning experiments having two groups of equal but small size, investigators face the uncertainty of power calculations that rely on asymptotic methods. This paper presents a method for determining power for two-sided tests. I compare two randomization tests, Fisher's exact test (FET), and the mid-P (MID), with the uncorrected chi-square test (CHI). Results show power as a function of relative risk for these methods, and assesses their relative power and type I error rates. MID is shown to have intermediate power between CHI, which is the most powerful, and FET, the least powerful. Situations are shown in which CHI and MID occasionally exceed the nominal level of alpha.
A B Davis
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Statistics in medicine     Volume:  12     ISSN:  0277-6715     ISO Abbreviation:  Stat Med     Publication Date:  1993 Apr 
Date Detail:
Created Date:  1993-07-19     Completed Date:  1993-07-19     Revised Date:  2000-12-18    
Medline Journal Info:
Nlm Unique ID:  8215016     Medline TA:  Stat Med     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  777-87     Citation Subset:  IM    
Department of Family Medicine, College of Medicine, University of Oklahoma Health Sciences Center, Ok. City 73190.
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MeSH Terms
Data Interpretation, Statistical*
Models, Statistical
Random Allocation
Research Design*

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