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help > RE: Contrast specification for Group comparison in a multi-center RCT (controlling for scanner)
Jan 13, 2021 09:01 PM | Marcel Daamen
RE: Contrast specification for Group comparison in a multi-center RCT (controlling for scanner)
Dear Till,
I wonder whether the model is overparameterized because you should only need 7 variables for dummy-coding the 8 centers/ scanners (i.e. scanner 8 implicitly specified by a "0" for all seven regressors)?
Best wishes,
Marcel
Originally posted by Till Langhammer:
I wonder whether the model is overparameterized because you should only need 7 variables for dummy-coding the 8 centers/ scanners (i.e. scanner 8 implicitly specified by a "0" for all seven regressors)?
Best wishes,
Marcel
Originally posted by Till Langhammer:
Dear Alfonso and Forum members,
I would like to compare different groups. Groups are diagnosis groups in an RCT for different anxiety disorders.
We have 8 different sites and therefore different scanners.
My Model
[1 -1 0 0 0 0 0 0 0 0 0 0]
[patients controls age sex center1 center2 center3 center4 center5 center6 center7 center8]
I am not sure if this works. The results explorer and folder is named
"patients(1).controls(-1).age(0).sex(0).Dr7573199821223284"
I would have expected:
"patients(1).controls(-1).age(0).sex(0).center1(0).center2(0).center3(0).center4(0).center5(0).center6(0).center7(0).center8(0)"
I chose user defined between subject contrast and inserted [1 -1 0 0 0 0 0 0 0 0 0 0], as it is not possible to choose this contrast in the drop down menu.
How can I check if CONN calcualted the correct model?
Thanks
Till
I would like to compare different groups. Groups are diagnosis groups in an RCT for different anxiety disorders.
We have 8 different sites and therefore different scanners.
My Model
[1 -1 0 0 0 0 0 0 0 0 0 0]
[patients controls age sex center1 center2 center3 center4 center5 center6 center7 center8]
I am not sure if this works. The results explorer and folder is named
"patients(1).controls(-1).age(0).sex(0).Dr7573199821223284"
I would have expected:
"patients(1).controls(-1).age(0).sex(0).center1(0).center2(0).center3(0).center4(0).center5(0).center6(0).center7(0).center8(0)"
I chose user defined between subject contrast and inserted [1 -1 0 0 0 0 0 0 0 0 0 0], as it is not possible to choose this contrast in the drop down menu.
How can I check if CONN calcualted the correct model?
Thanks
Till
Threaded View
Title | Author | Date |
---|---|---|
Till Langhammer | Jan 12, 2021 | |
Marcel Daamen | Jan 13, 2021 | |
Alfonso Nieto-Castanon | Jan 26, 2021 | |
Till Langhammer | Jan 26, 2021 | |
Till Langhammer | Jan 14, 2021 | |
Marcel Daamen | Jan 14, 2021 | |