[1] Univ Arizona, Coll Med, Arizona Resp Ctr, 1501 North Campbell Ave,POB 245030, Tucson, AZ 85724 USA
[2] Univ Michigan Hlth Syst, Div Pulm & Crit Care Med, Ann Arbor, MI USA
[3] C TASC Clin Trials & Surveys Corp, Owings Mills, MD USA
[4] Mayo Clin, Coll Med, Div Pulm & Crit Care Med, Rochester, MN USA
[5] Univ Colorado, Denver Sch Med, Div Pulm Sci & Crit Care Med, Aurora, CO USA
[6] Univ Pittsburgh, Sch Med, Div Pulm & Crit Care Med, Pittsburgh, PA USA
[7] Temple Univ, Ctr Inflammat Translat & Clin Lung Res, Sch Med, Philadelphia, PA 19122 USA
[8] Johns Hopkins Univ, Sch Med, Div Pulm & Crit Care Med, Baltimore, MD USA