1. Veterans Affairs Greater Los Angeles Healthcare System, Geriatric Research, Education and Clinical Center, North Hills, California
2. Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
3. Veterans Affairs Greater Los Angeles Healthcare System, Division of Pulmonary Medicine, North Hills, California
4. Department of Emergency Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
5. University of California, San Diego, San Diego, California
6. Wayne State University, Detroit, Michigan
7. John D. Dingell Veterans Affairs Medical Center, Detroit, Michigan