Dear Freesurfer experts, I have a quick question regarding the appropriate design (DOSS or DODS) to be used with QDEC when comparing 2 groups for cortical thickness and LGI values.
So far I have used DODS first to look for an age-cortical thickness interaction in both groups. I used the real ages and also demeaned the age variable in my analysis. I entered age as a covariate and as a nuisance factor also. I have gender and diagnosis as discrete and eTIV as nuisance in both analysis. Neither was significant. After this I used DOSS in QDEC to compare groups groups for both cortical thickness and LGI. My questions relates to the use of age as a covariate in DOSS. Is it appropriate to enter age as covariate in DOSS given that DOSS assumes that both groups have the same slope? I have looked through the archives and online for an answer to this but I am still a bit confused. Any help or advice on this would be greatly appreciated. Thank you so much in advance. Best wishes Marco
_______________________________________________ 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.
