Hi, I was wondering if there is a way to run statistical tests, such as a 2-way ANCOVA, on QDEC but without the interaction effect. I ran a 2-way ANCOVA for thickness measures for a longitudinal study, and no interaction effect was found. Therefore, I would like to run the same test but without the interaction effect and see if there are other group effects. Please let me know if there is a way to do this in QDEC or any other statistical programs in FreeSurfer. Thank you!
-Shannon
Hi Shannon, you can use the DOSS (different offset/same slope) instead of DODS doug
On 08/20/2012 03:47 PM, Shannon Kogachi wrote:
Hi, I was wondering if there is a way to run statistical tests, such as a 2-way ANCOVA, on QDEC but without the interaction effect. I ran a 2-way ANCOVA for thickness measures for a longitudinal study, and no interaction effect was found. Therefore, I would like to run the same test but without the interaction effect and see if there are other group effects. Please let me know if there is a way to do this in QDEC or any other statistical programs in FreeSurfer. Thank you!
-Shannon
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
Hi Doug, I just wanted to double check on what you mean. I want to run statistical models without the interaction term. When I ran a test using DOSS and co-varying for sex, age, and ICV, I chose two discrete factors (study, sex), 1 covariate (age), and 1 nuisance factor (ICV). The results I got were the same as when I ran this in SAS but with the interaction term included: model &yvar = study Sex study*sex age ICV
Is there a way in QDEC to run models without the interaction term (ex: study*sex)?
Thanks!
-Shannon
On Fri, Aug 24, 2012 at 1:05 PM, Douglas N Greve greve@nmr.mgh.harvard.eduwrote:
Hi Shannon, you can use the DOSS (different offset/same slope) instead of DODS doug
On 08/20/2012 03:47 PM, Shannon Kogachi wrote:
Hi, I was wondering if there is a way to run statistical tests, such as a 2-way ANCOVA, on QDEC but without the interaction effect. I ran a 2-way ANCOVA for thickness measures for a longitudinal study, and no interaction effect was found. Therefore, I would like to run the same test but without the interaction effect and see if there are other group effects. Please let me know if there is a way to do this in QDEC or any other statistical programs in FreeSurfer. Thank you!
-Shannon
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 greve@nmr.mgh.harvard.edu Phone Number: 617-724-2358 Fax: 617-726-7422
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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.
Hi Shannon, there is not a way in QDEC or with an FSGD file. You'll have to create a design matrix and feed that into mri_glmfit with the --X option. Let me know if you need any more assistance. doug
On 9/10/12 5:43 PM, Shannon Kogachi wrote:
Hi Doug, I just wanted to double check on what you mean. I want to run statistical models without the interaction term. When I ran a test using DOSS and co-varying for sex, age, and ICV, I chose two discrete factors (study, sex), 1 covariate (age), and 1 nuisance factor (ICV). The results I got were the same as when I ran this in SAS but with the interaction term included: model &yvar = study Sex study*sex age ICV
Is there a way in QDEC to run models without the interaction term (ex: study*sex)?
Thanks!
-Shannon
On Fri, Aug 24, 2012 at 1:05 PM, Douglas N Greve <greve@nmr.mgh.harvard.edu mailto:greve@nmr.mgh.harvard.edu> wrote:
Hi Shannon, you can use the DOSS (different offset/same slope) instead of DODS doug On 08/20/2012 03:47 PM, Shannon Kogachi wrote: > Hi, > I was wondering if there is a way to run statistical tests, such as > a 2-way ANCOVA, on QDEC but without the interaction effect. I ran a > 2-way ANCOVA for thickness measures for a longitudinal study, and no > interaction effect was found. Therefore, I would like to run the same > test but without the interaction effect and see if there are other > group effects. Please let me know if there is a way to do this in QDEC > or any other statistical programs in FreeSurfer. Thank you! > > > -Shannon > > > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu <mailto:Freesurfer@nmr.mgh.harvard.edu> > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer -- Douglas N. Greve, Ph.D. MGH-NMR Center greve@nmr.mgh.harvard.edu <mailto:greve@nmr.mgh.harvard.edu> Phone Number: 617-724-2358 <tel:617-724-2358> Fax: 617-726-7422 <tel:617-726-7422> Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting <http://surfer.nmr.mgh.harvard.edu/fswiki/BugReporting> FileDrop: www.nmr.mgh.harvard.edu/facility/filedrop/index.html <http://www.nmr.mgh.harvard.edu/facility/filedrop/index.html> _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu <mailto: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.
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