1. Division of Sleep and Chronobiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
2. Biobehavioral Nursing and Health Informatics, School of Nursing, University of Washington, Seattle, Washington, USA.
3. Harborview Injury Prevention and Research Center, Harborview Medical Center, Seattle, Washington, USA.
4. Division of Pulmonary, Critical Care and Sleep Medicine, School of Medicine, University of Washington, Seattle, Washington, USA.