[1] Univ Calif San Diego, Div Pulm Crit Care & Sleep Med, 9300 Campus Point Dr,MC 7381, La Jolla, CA 92037 USA
[2] Northwestern Univ, Feinberg Sch Med, Div Pulm & Crit Care Med, Chicago, IL 60611 USA
[3] Univ Michigan, Div Pulm & Crit Care Med, Ann Arbor, MI 48109 USA
[4] Salem Vet Affairs Med Ctr, Div Pulm & Sleep Med, Salem, VA USA
[5] Univ Virginia, Dept Med, Charlottesville, VA USA
[6] Univ N Carolina, Div Pulm Dis & Crit Care Med, Chapel Hill, NC 27515 USA
[7] Amer Thorac Soc, New York, NY USA
[8] Mt Auburn Hosp Beth Israel Lahey Hlth, Div Pulm & Crit Care Med, Dept Med, Cambridge, MA USA
[9] Harvard Med Sch, Boston, MA 02115 USA