1. Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, Canada
2. Department of Pharmacology & Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver, Canada
3. Division of Respirology, Centre for Sleep Medicine and Circadian Biology, University of Toronto, Toronto, Canada
4. Sleep Research Laboratory of the Toronto Rehabilitation Institute, University Health Network Toronto, Toronto, Canada
5. Pulmonary and Critical Care Medicine, Faculty of Medicine, University of California San Diego, San Diego, U.S.A.
6. Division of Pulmonary and Critical Care Medicine, Department of Medicine, School of Medicine, Johns Hopkins University, Baltimore, U.S.A.
7. Section of Pulmonary & Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, U.S.A.