1. 1Department of Thoracic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee.
2. 2Section of Thoracic Surgery, Tennessee Valley VA Healthcare System, Nashville, Tennessee.
3. 3Department of Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee.
4. 4Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University Medical Center, Nashville, Tennessee.
5. 5Division of Thoracic Surgery, University of Cincinnati, Cincinnati, Ohio.
6. 6Division of Pulmonary, Allergy, and Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
7. 7Section of Pulmonary and Critical Care Medicine, Boston Medical Center, Boston, Massachusetts.