[1] Univ Calif Riverside, Dept Internal Med, Riverside, CA USA
[2] Cleveland Clin, Resp Inst, Dept Pulm & Crit Care Med, Cleveland, OH USA
[3] Cleveland Clin, Community Care Inst, Dept Internal Med, Cleveland, OH USA
[4] Cleveland Clin, Fairview Hosp, Dept Internal Med, Cleveland, OH USA
[5] Thomas Jefferson Univ, Dept Emergency Med, Philadelphia, PA USA
[6] Univ Penn, Dept Emergency Med, Philadelphia, PA USA
[7] Univ Penn, Ctr Resuscitat Sci, Philadelphia, PA USA
[8] Cleveland Clin, Qualitat Hlth Sci, Cleveland, OH USA
[9] Cleveland Clin Fdn, Dept Pulm & Crit Care Med, A-90,9500 Euclid Ave, Cleveland, OH 44195 USA