[1] Intermt Med Ctr, Dept Med, Div Pulm & Crit Care Med, T4 STICU,5121 S Cottonwood St, Murray, UT 84107 USA
[2] Univ Utah, Sch Med, Dept Internal Med, Div Pulm & Crit Care Med, Salt Lake City, UT USA
[3] Univ Utah, Sch Med, Salt Lake City, UT USA
[4] Univ N Carolina, Dept Phys Med & Rehabil, Sch Med, Chapel Hill, NC 27515 USA
[5] Univ Wisconsin, Sch Med, Dept Med, Madison, WI USA
[6] Intermt Healthcare, Stat Data Ctr, Murray, UT USA
[7] Univ Utah, Sch Med, Dept Med, Div Epidemiol, Salt Lake City, UT USA
[8] Univ Utah, Sch Med, Dept Med, Div Infect Dis, Salt Lake City, UT USA
[9] Oregon Hlth & Sci Univ, Dept Med, Div Pulm Crit Care & Sleep Med, Portland, OR 97201 USA
[10] Intermt Med Ctr, Dept Emergency Med, Murray, UT 84107 USA
[11] Stanford Univ, Dept Emergency Med, Palo Alto, CA 94304 USA