Open AccessComments Regarding the Recent OAST Article
Author(s) -
Scott W. Miller,
Yuko Y. Palesch
Publication year - 2007
Publication title -
stroke
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.397
H-Index - 319
eISSN - 1524-4628
pISSN - 0039-2499
DOI - 10.1161/strokeaha.107.500355
Subject(s) - biostatistics , medicine , nonparametric statistics , bonferroni correction , multiple comparisons problem , statistics , test (biology) , analysis of variance , normality , epidemiology , econometrics , mathematics , pathology , psychiatry , paleontology , biology
To the Editor:A recent article by the Optimizing Reanalysis of Stroke Trials (OAST) Collaboration analyzed 55 stroke datasets with multiple tests and ranked them in order of the standardized test statistic; these ranks were then analyzed with a 2-way ANOVA.1 Although this article raises important issues, we have concerns regarding the methods.Firstly, ANOVA assumes approximate normality of the response outcome, which the ordinal ranks are not. ANOVA also assumes that the responses are independent, but this is not the case here, unless we have misunderstood the method. Analyzing the same datasets with multiple tests will induce a positive correlation among the test results; ignoring this correlation generally results in smaller probability …
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