1. Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Medicine; University of Florida College of Medicine; Gainesville Florida
2. Division of Pulmonary and Critical Care, Department of Medicine; Medical University of South Carolina; Charleston South Carolina
3. Division of Biostatistics and Epidemiology, Department of Medicine; Medical University of South Carolina; Charleston South Carolina
4. Division of Cytology, Department of Pathology; Medical University of South Carolina; Charleston South Carolina