1. Division of General Pediatrics, Department of Pediatrics and Communicable Diseases, and
2. Child Health Evaluation and Research Unit,
3. Department of Health Management and Policy, School of Public Health, and
4. Division of General Internal Medicine, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, Michigan; and
5. Gerald R. Ford School of Public Policy, University of Michigan, Ann Arbor, Michigan