Suppose I use PSM to balance confounders for treatment effect in observational studies, and the logistic model for the PS includes age, gender, comorbidities.
And then use either stratification or matching or weighting (eg in tutorial by http://personalpages.manchester.ac.uk/staff/mark.lunt/) followed by PS matched linear regression.
Can the PS matched linear regression then have age, gender, comorbidities as covariates?
Conceptually it seems to me that you should be able to, but not if PS is used for model reduction and the PS is added as a covariate (as some people do https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4004383/).
Thank you