From the Intensive Care Unit (ARD, SSM, DJC), Alfred Hospital, Melbourne, Australia; Department of Epidemiology and Preventive Medicine (ARD, SSM, MJB, RB, DJC), Monash University, Melbourne, Australia; Intensive Care Unit (RB), Austin Hospital, Melbourne, Australia; Intensive Care Unit (GSD, SRF), Royal North Shore Hospital, Sydney, Australia; Northern Clinical School (GSD), University of Sydney, Sydney, Australia; The George Institute for Global Health (SRF), University of Sydney, Sydney, Australia; Department of Medicine (DKH), Queens University, Kingston, Canada.