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Dear experts,
I am conducting a group analysis and wanted to confirm that the set up below accurately addresses our research question. Thanks for your help, much appreciated!
Background:
* We have two groups (intervention vs control) and two timepoints (pre vs post) * Our data have already been processed and stacked with long_mris_slopes where pc1 is the measure of interest (post - pre). * Our covariates are sex (male vs female), age, and MMSE scores. * Thus, our model has 4 groups (2 factors/2 levels): * int_male * int_female * con_male * con_female * We’re using DODS * We’re running the analysis with mri_glmfit in the Longitudinal Two Stage Model
As such, we want test whether there are greater changes in the intervention group vs control group in the pc1 measure, adjusting for the influence of sex, age, and MMSE.
This is our FSGD: GroupDescriptorFile 1 Title Between-group Class int_male Class int_female Class con_male Class con_female Variables age mmse Input 001.MR int_male 30 25 Input 002.MR int_female 40 22 Input 003.MR con_male 60 29 Input 004.MR con_female 60 21 …
And this is the contrast matrix +0.5 +0.5 -0.5 -0.5 +0 +0 +0 +0 +0 +0 +0 +0
With the above contrast matrix, our interpretation would be:
* Intervention > control = positive result * Intervention < control = negative result
Is this the correct set up and interpretation?
Thanks for taking the time, Best regards, Nárlon Cássio
Nárlon Cássio Boa Sorte Silva PhD (He, Him, His) CIHR and MSHR BC/PARF Postdoctoral Research Fellow Aging, Mobility, and Cognitive Health Lab Djavad Mowafaghian Centre for Brain Health Department of Physical Therapy, Faculty of Medicine University of British Columbia Vancouver, Canada Twitter: @BoaNarlon[X]