controlling for site clustering

[#1]

A large data set of >200,000 patients is from 125 hospitals. I am analyzing difference in outcomes ( mortality ( nominal) and Length of stay ( continuous) based on admission source. The other predictor variables include age, diagnostic categories, severity of illness score etc.

I need to account or site clustering. I can do this by adding site ID in the Fit model...I can make it into random effect also as I read on one of the discussion posts.

I wanted to ensure this is appropriate method to account for the clustering. I will be doing linear regression by standard least square and nominal logistic regression.

thank you for looking into it

[#2]

Yes, it sounds like a logistic regression model with covariates and site in the linear predictor is appropriate. You might also include cross terms for potential interaction effects such as length of stay at a particular site.