1. Department of Health Policy and Management, Johns Hopkins University Bloomberg School of Public Health , Baltimore, MD 21205 , United States
2. Division of Health Policy and Management, University of Minnesota School of Public Health , Minneapolis, MN 55455 , United States
3. George Mason University Schar School of Policy and Government , Arlington, VA 22201 , United States
4. RAND Corporation , Pittsburgh, PA 15213 , United States
5. Department of Medicine, Division of General Internal Medicine and Health Services Research, University of California Los Angeles , Los Angeles, CA 90095 , United States
6. Department of Health Policy and Management, University of California Los Angeles , Los Angeles, CA 90095 , United States