[1] Yale Univ, Sect Pulm Crit Care & Sleep Med, Dept Internal Med, Sch Med, POB 208057,300 Cedar St TAC,441 South, New Haven, CT 06520 USA
[2] Yale Sch Publ Hlth, Yale Ctr Analyt Sci, New Haven, CT USA
[3] Yale Univ, Dept Chron Dis Epidemiol, Sch Publ Hlth, New Haven, CT USA
[4] Med Univ South Carolina, Div Pulm Crit Care & Sleep Med, Dept Internal Med, New Haven, CT USA