rxLinMod was designed to produce results matching SAS's results by default. If the default rxLinMod results still do not match the SAS results or there are no factor variables, check whether the rxLinMod call uses fweights or pweights.
rxLinMod() allows both "pweights" and "fweights" and the former corresponds to the weights used by SAS and R. "fweights" are extremely useful for some types of computations, though most other programs do not support them.
Changing "fweights" to "pweights" in the call to rxLinMod should get the same results as R and SAS.
Article ID: 3104226 - Last Review: Oct 29, 2015 - Revision: 1