1. Department of Thoracic Medicine and Surgery, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania;
2. Center for Tobacco Research and Intervention, Department of Medicine, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin;
3. Division of Pediatric Pulmonology, Allergy, and Sleep Medicine, Riley Hospital for Children, Indianapolis, Indiana;
4. The Pulmonary Center, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts; and
5. Division of Pulmonary and Critical Care Medicine, Johns Hopkins University, Baltimore, Maryland