[1] Univ Penn, Sch Nursing, Philadelphia, PA USA
[2] Corporal Michael J Crescenz Vet Affairs Med Ctr, Philadelphia, PA USA
[3] Univ Penn, Perelman Sch Med, Ctr Sleep & Circadian Neurobiol, Philadelphia, PA USA
[4] Univ Penn, Dept Anesthesiol & Crit Care, Perelman Sch Med, Philadelphia, PA USA
[5] Univ Penn, Dept Med, Div Sleep Med, Perelman Sch Med, Philadelphia, PA USA
[6] Geisinger, Dept Populat Hlth Sci, 100 North Acad Ave, Danville, PA 17822 USA