1. Department of Medicine
2. School of Nursing, University of Pennsylvania, and
3. Medical Intensive Care Unit, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania; and
4. Interdivisional Department of Critical Care, University of Toronto, and
5. Division of Respirology, Department of Medicine, Mount Sinai Hospital/University Health Network, Toronto, Ontario, Canada
6. Pulmonary, Allergy, and Critical Care Division, Department of Medicine; and
7. Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine at the University of Pennsylvania