Great, thanks so much!
But I am having difficulty understanding how to construct the contrast to answer the following question "Is the interaction between group (CU/CI) and cortisol significant regressing out the effect of sex, age, APOE_carrier, abeta and ptau?" It seems like the contrast would be the same as before.. Can you help me with this?

Thanks again!

Laura Willers de Souza

PhD Student in Pharmacology and Therapeutics

Zimmer Lab - Federal University of Rio Grande do Sul

- Porto Alegre/RS - Brazil

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Douglas N. Greve Wed, 15 Nov 2023 06:54:36 -0800


Yes, that looks right (assuming that cortisol is your first variable)



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On 11/7/2023 3:49 PM, Laura Willers de Souza wrote:

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Hello FreeSurfer Developers,

Following the FSGD examples on the website, I built the following test:

Question: Is there an association between cortisol and cortical thickness regressing out the effect of sex, age, APOE4_carrier (1=1 or 2 alleles, 0=no alleles), abeta, ptau, diagnosis (CU and CI)? Regressors: 2 factors (sex, diagnosis) with 2 levels each, 5 covariates (age, APOE4_carrier (1=1 or 2 alleles, 0=no alleles), abeta, ptau, cortisol) >> 24 regressors

Contrast: 0 0 0 0 0.5 -0.5 0.5 -0.5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
FSGD:
GroupDescriptorFile 1
Title CSF_semgrupos
Class MaleCU
Class MaleCI
Class FemaleCU
Class FemaleCI
Variables Cortisol Age ABETA ptau APOE4_carrier
Input 098_S_4003_I224603 MaleCI 11 81.3 741.5 22.83 1

Does this feel right to you?

I am having difficulty understanding how to construct the contrast to answer the following question "Is the interaction between group (CU/CI) and cortisol significant regressing out the effect of sex, age, APOE_carrier, abeta and ptau?" It seems like the contrast would be the same as before.. Can you guys help me with this?

Thanks in advance!

*Laura Willers de Souza *

PhD Student in Pharmacology and Therapeutics

Zimmer Lab - Federal University of Rio Grande do Sul

- Porto Alegre/RS - Brazil