[1] Univ Pittsburgh, Dorothy P & Richard P Simmons Ctr Interstitial Lu, UPMC, Pittsburgh, PA 15213 USA
[2] Univ Pittsburgh, Div Pulm Allergy & Crit Care Med, Pittsburgh, PA 15213 USA
[3] Univ Pittsburgh, Sch Nursing, Pittsburgh, PA 15213 USA
[4] Yale Univ, Sch Med, Pulm Crit Care & Sleep Med, New Haven, CT 06520 USA