You should make sure to have a balanced design (ie, approx the same pats and cons at each site). Then include site as a regressor, ie, if you had two groups and two sites, you would have four regressors. You could then test for the effect of group, the effect of site, and the interaction. If there is an interaction, then it is hard to interpret the differences between groups.
On 05/08/2017 01:24 PM, Laura Ferrero Montes wrote: > Dear FS team, > In case I have data from different centers and I would like to do a > group analysis between Patients and Controls, how different centers > effects could be regressed out? Should I have to analyze if there is > an interaction between center and group? > I have seen examples of continuous variables and groups but not in the > case of categorical ones. > Thank you, > Laura > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > -- Douglas N. Greve, Ph.D. MGH-NMR Center gr...@nmr.mgh.harvard.edu Phone Number: 617-724-2358 Fax: 617-726-7422 Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting FileDrop: https://gate.nmr.mgh.harvard.edu/filedrop2 www.nmr.mgh.harvard.edu/facility/filedrop/index.html Outgoing: ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/ _______________________________________________ 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.
