1. Ezra Golberstein ( ) is an assistant professor in the Division of Health Policy and Management, School of Public Health, University of Minnesota, in Minneapolis.
2. Kayo Walsh is a data manager and programmer in the Department of Health Care Policy at Harvard Medical School, in Boston, Massachusetts.
3. Yulei He was an associate professor of health care policy at Harvard Medical School when he made his contributions to this paper.
4. Michael E. Chernew is a professor in the Department of Health Care Policy at Harvard Medical School.