[1] Univ Calif Los Angeles, David Geffen Sch Med, Div Pulm & Crit Care Med, Los Angeles, CA 90095 USA
[2] Greater Los Angeles Vet Affairs Healthcare Syst, Ctr Study Healthcare Innovat Implementat & Policy, Los Angeles, CA USA
[3] Harvard Med Sch, Beth Israel Deaconess Med Ctr, Ctr Resuscitat Sci, Dept Emergency Med, Boston, MA 02115 USA
[4] Univ Calif Los Angeles, David Geffen Sch Med, Div Hosp Med, Los Angeles, CA 90095 USA
[5] Harvard Med Sch, Beth Israel Deaconess Med Ctr, Div Pulm Crit Care Med & Sleep Med, Boston, MA 02115 USA
[6] Montefiore Med Ctr, Div Crit Care Med, 111 E 210th St, Bronx, NY 10467 USA