Linked Life Data

7951275

Source:http://linkedlifedata.com/resource/pubmed/id/7951275

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1994-12-19
pubmed:abstractText
Datasets representing randomized, parallel-groups designs were analyzed by repeated measurements ANOVA and linear trend analysis with and without baseline values being covaried. ANOVA tests for the between-groups main effect, groups X times interaction, and differences in linear trends across time periods are shown to be seriously conservative or seriously nonconservative, depending on the direction and significance of chance baseline mean difference. Inclusion of baseline scores as a covariate in the repeated measurements ANOVA provides appropriate correction for the between-groups (average) effect across time, but the covariate provides no correction for the within-subject effects that are concerned with differences in the rates or patterns of change across time. If one desires to evaluate differences between patterns of treatment-induced change, tests of significance for differences in group means on composite trend scores with covariance correction for baseline are recommended. If covariance correction is not or cannot be employed, the potentially "favorable" or "unfavorable" influence of chance baseline differences on tests of significance needs to be explicitly recognized.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
1054-3406
pubmed:author
pubmed:issnType
Print
pubmed:volume
4
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
199-216
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Implications of chance baseline differences in repeated measurement designs.
pubmed:affiliation
Department of Psychiatry and Behavioral Sciences, University of Texas Medical School, Houston 77225.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.