[1] Baylor Coll Med, Sect Pulm Crit Care & Sleep, Houston, TX 77030 USA
[2] Univ Michigan, Ann Arbor, MI 48109 USA
[3] Natl Taiwan Univ Hosp, Dept Emergency Med, Taipei, Taiwan
[4] GSK Res & Dev, King Of Prussia, PA USA
[5] Azusa Pacific Univ, Dept Phys Therapy, Azusa, CA USA
[6] Johns Hopkins Univ, Baltimore, MD USA
[7] Morehouse Sch Med, Pulm & Crit Care Med Div, Atlanta, GA 30310 USA
[8] Harvard Med Sch, Brigham & Womens Hosp, Dept Med, Channing Div Network Med, Boston, MA USA
[9] Harvard Med Sch, Brigham & Womens Hosp, Dept Med, Pulm & Crit Care Div, Boston, MA USA
[10] Natl Jewish Hlth, Dept Med, Denver, CO USA
[11] Univ North Carolina Chapel Hill, Dept Biostat, Chapel Hill, NC USA