That looks right to me. If you use a DOSS model and have a lot of subjects, I don't think there should be a problem with so many classes.
On 04/09/2018 09:50 AM, C.P.E. Rollins wrote: > Hi Douglas, > > Thanks for your response. I just wanted to confirm how the FSGD and > contrast files might look for the multicentre study. If I'm to create a > separate class for each combination of diagnosis, sex, and center, would > there then be 24 classes? (as there are 2 diagnoses (patient vs. > control), 2 sex, and 6 centres). > For instance: > GroupDescriptorFile 1 > Group control_Male_centre1 > Group control_Female_centre1 > Group control_Male_centre2 > Group control_Female_centre2 > Group control_Male_centre3 > Group control_Female_centre3 > Group control_Male_centre4 > Group control_Female_centre4 > Group control_Male_centre5 > Group control_Female_centre5 > Group control_Male_centre6 > Group control_Female_centre6 > Group patient_Male_centre1 > Group patient_Female_centre1 > Group patient_Male_centre2 > Group patient_Female_centre2 > ... > > Then, my contrast between patients and controls would look like > 1 1 1 1 1 1 1 1 1 1 1 1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 0 > for a doss model, if I'm additionally controlling for age, or 24 zeros > (instead of 1) for a dods model? > Moreover, should I expect any issues with using such a high number of > classes? > > Thanks again, > Colleen > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer The information in this e-mail is intended only for the person to whom it is addressed. If you believe this e-mail was sent to you in error and the e-mail contains patient information, please contact the Partners Compliance HelpLine at http://www.partners.org/complianceline . If the e-mail was sent to you in error but does not contain patient information, please contact the sender and properly dispose of the e-mail.
