1. School of Nursing, University of California, Los Angeles, Los Angeles, CA, USA;
2. Geriatric Research, Education and Clinical Center, VA Greater Los Angeles Healthcare System, North Hills, CA, USA;
3. David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA;
4. Department of Psychosocial and Community Health, School of Nursing, University of Washington, Seattle, WA, USA;
5. Cousins Center for Psychoneuroimmunology, Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA;
6. School of Medicine, Stanford University, Palo Alto, CA, USA