1. Division of Pulmonary, Allergy, and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL, United States
2. Johns Hopkins University, Baltimore, MD, United States
3. Pulmonary and Critical Care Medicine, University of Michigan, Ann Arbor, MI, United States
4. Univ of Illinois, Chicago, IL, United States
5. Wake Forest School of Medicine, Winston Salem, NC, United States
6. Pulmonary and Critical Care, UCLA, Los Angeles, CA, United States
7. Weill Cornell Medicine, New York, NY, United States
8. University of Alabama Birmingham & Birmingham VA Medical Center, Birmingham, AL, United States