In Simbiology, should the categorical variables be assigned as group variable or covariate in the dataset?

I am using Simbiology for population pharmacokinetic model development. I use non-linear mixed effect modelling approach. I have a doubt in the intial assignment of data type in the dataset.

Suppose I have age and gender in the dataset. Clearly, I will assign age as covariate. Now gender is also a covariate. But there is a option in the dataset type which is group variable.

Now I am confused on whether I should assign gender as covariate or group variable.?

I am attaching a screenshot for the reference.

Answer 1

[Praveen Kumar M]

Oh. That's a clear answer. I have a logical query. Among the covariate, one is a categorical variable (gender) and another is a continuous variable (age). How do I incorporate this information in the dataset / modelling?

[Jeremy Huard]

It is not necessary to define it as categorical. But covariates require numerical data in SimBiology. In your case, since you have a binary covariate, you could set gender to 1 for female, 0 for male.

[Praveen Kumar M]

Thank you. Clear now.

Answer 2

[Jeremy Huard]

Group variable defines an index for a subject/experiment. In your dataset, ID is a group variable. Gender and age can be both covariates.