Can varying co-payment rates by risk reduce cost and improve health outcomes?

A RAND study published in the American Journal of Managed Care (“Varying Pharmacy Benefits With Clinical Status: The Case of Cholesterol-lowering Therapy“) claims that managed care administrators may be able to vary pharmaceutical co-payment amounts by risk group in order to reduce cost and improve health outcomes.  Thus study looks at Cholesterol-Lowering pharmaceuticals.  Co-payments are…