1. Division of Pulmonary and Critical Care Medicine University of California Los Angeles Los Angeles CA USA
2. Division of Pulmonary, Allergy and Critical Care Medicine Duke University Medical Center Durham NC USA
3. Department of Biostatistics and Bioinformatics Duke University Medical Center Durham NC USA
4. Clinical Research Institute Duke University Medical Center Durham NC USA
5. Rho Federal Systems Division Rho Durham NC USA
6. Department of Pathology Duke University Medical Center Durham NC USA
7. Division of Respirology University Health Network, University of Toronto Ontario Canada
8. Respiratory Institute/Division of Pulmonary and Critical Care Medicine Cleveland Clinic Cleveland OH USA
9. Division of Pulmonary and Critical Care Medicine John Hopkins University Baltimore MD USA
10. Division of Allergy, Immunology, and Transplantation National Institute of Allergy and Infectious Diseases Rockville MD USA