Can you include the previous emails in your current email?
On 12/14/2021 3:46 PM, Laura Willers de Souza wrote:
External Email - Use Caution
Dear Douglas,
Thank you so much for your answer!
Sorry, but I don't think I explained myself correctly in the previous email.
I want to analyze the difference in cortical thickness between two groups (CU and CI), adjusting for a covariate (cortisol CSF) and the interaction between them.
So my model would be: cortical thickness ~ diagnosis + CSF cortisol + diagnosis*CSF cortisol
Using the GLM DODS, the contrasts, according to the wiki example (https://surfer.nmr.mgh.harvard.edu/fswiki/Fsgdf2G1V https://secure-web.cisco.com/1qbucUNWhNS-2uW6Lox1w2bMK8EUHU0lm2XC7ywMcgAz1opgFdJ9TpOloRtF1uTmyVc70aldT5QkaELBu9kC0X6YiGpVUzZ3hV6ImEDrYAPF9VgAmDOudc6SysPVlhaUvzzGFirVYNLChsA_roK3faZNzYnWbdGPEJSgasor3qtQpKeAN7XvnQ4X24hWQfi35Rh8kF9yIsndHzOZGNxOdCH7U2CUMc9KxEL3N9u2-8weS-Fz01NHj2B_xMyBA8BlbS0n_wekioRXCPViGU3a_0zVQxE5Wu9sLPwFsQ3peECtbgAqHVmzWbyks9AhB3fWY/https%3A%2F%2Fsurfer.nmr.mgh.harvard.edu%2Ffswiki%2FFsgdf2G1V), would be:
To verify if only the diagnosis regression coefficient is significant (diagnosis changes cortical thickness regardless of cortisol):
1 -1 0 0
To verify if the regression coefficient of the interaction between diagnosis and cortisol is significant (the two change cortical thickness dependently):
0 0 1 -1
To verify if only the cortisol regression coefficient is significant (cortisol changes cortical thickness regardless of diagnosis):
0 0 0.5 0.5
Are these contrasts corret to represent the model we designed?
Thank you so much again!
Best regards,
*Laura Willers de Souza *
Master Student in Biochemistry
Zimmer Lab - Federal University of Rio Grande do Sul
- Porto Alegre/RS - Brazil