[1] Univ North Carolina Chapel Hill, Dept Med, Div Pulm Dis & Crit Care Med, Chapel Hill, NC 27599 USA
[2] Univ N Carolina, UNC Sch Med, Dept Psychiat, Chapel Hill, NC USA
[3] Univ North Carolina Chapel Hill, Gillings Sch Global Publ Hlth, Dept Epidemiol, Chapel Hill, NC USA
[4] Duke Univ, Dept Med, Div Pulm Allergy & Crit Care Med, Durham, NC USA
[5] Univ North Carolina Chapel Hill, Div Geriatr Med, Chapel Hill, NC USA
[6] Univ North Carolina Chapel Hill, Dept Med, Palliat Care Program, Chapel Hill, NC USA
[7] Mem Sloan Kettering Canc Ctr, Dept Med Anesthesia & Crit Care, New York, NY USA
[8] Cornell Univ, Weill Cornell Med Coll, New York, NY USA