I wonder if there's a selection effect where on the one hand particularly demanding people avoid Kaiser because of the somewhat impersonal policies and practice

I wonder if there's a selection effect where on the one hand particularly demanding people avoid Kaiser because of the somewhat impersonal policies and practices, and on the other hand as an HMO Kaiser enjoys a much lower percentage of indigent and high-risk patients, which altogether permit Kaiser to build a system around the 80% instead of the 20%.