In SAS to model 1s rather than 0s, we use the descending option. We do this because by default, proc logistic models 0s rather than 1s.
What happens in case of R’s glm function? Does it model for 1 or 0? Is there a way to change it?
glm in R models for 1s by default.
I see couple of things in the below link to change the default behavior, please check.