1 Center for Chronic Disease Outcomes Research, Minneapolis Veterans Affairs Health Care System and Department of Medicine, University of Minnesota, Minneapolis, Minnesota.
2 Center for Chronic Disease Outcomes Research, Minneapolis Veterans Affairs Health Care System, Minneapolis, Minnesota.
3 Durham Veterans Affairs Health Care System and Department of Medicine, Duke University Medical Center, Durham, North Carolina.
4 Center for Healthcare Organization and Implementation Research, Boston Veterans Affairs Health Care System and Department of Health Policy and Management, Boston University School of Public Health, Boston, Massachusetts.