Effect of premium, copayments, and health status on the choice of health plans.

Objective: Explore effects of comorbidity and prior health care utilization on choice of employee health plans with different levels of cost sharing.

Data Sources/study Setting: Mayo Clinic employees in Rochester, Minnesota (MCR) under age 65 in January 2004; N = 20,379.

Study Design: Assessment of a natural experiment where self-funded medical care benefit options were changed to contain costs within a large medical group practice.