1 Division of Pulmonary and Critical Care Medicine, Rush Medical College and Rush University Medical Center, Chicago, IL. Electronic address: rbalk@rush.edu.
2 Critical Care Medicine Department, National Institutes of Health Clinical Center, Bethesda, MD.
3 Premier Research Services, Charlotte, NC.
4 Medical Affairs-Americas/East Asia and Global Health Economics and Outcomes, bioMérieux USA, Durham, NC; Medicine and International Relations, University of California San Diego, San Diego, CA; Health Policy and Management, University of North Carolina, Raleigh, NC.