There is a data model from mini-Sentinel. It is essentially a subset of the OMOP version (though not specifically designed as such). For example, it does not include costs, and it is less flexible in terms of how it handles “observations” that are not laboratory measurements. It is located here.
Kaiser has their own model, but I don’t know of any public details about it.
I2B2 might have something that I have never looked into carefully. Others know more than I do about other data models, but I thought I would respond in the hope that others might provide additional clarifications. I think @Daniella_Meeker or @schillil might have done some detailed investigations and published them.