Marginal structural models

[JJ24]

Hi community,

I’m learning MSM model and find a helpful paper published by SAS: https://support.sas.com/content/dam/SAS/support/en/books/analysis-of-observational-health-care-data-...

In the example, the key time dependent variable is treatment and weights are calculated with treatment as the dependent variable. If I have three time dependent predictors and want to evaluate their effects, should I calculate weights in separate models with each of the three time dependent predictors as the dependent variable and then run final model with specific weight for the time dependent predictor? Does this mean we can't evaluate  the three time dependent predictors in one final model?

Thanks.