1. University of Washington, Seattle, WA, USA
2. California State University San Marcos, San Marcos, CA, USA
3. Oregon State University, Corvallis, OR, USA
4. UC Davis Medical Center, Sacramento, CA, USA
5. VA Medical Center, Seattle, WA, USA
6. Group Health Research Institute of Group Health Cooperative, Seattle, WA, USA
7. Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, NY, USA
8. University of Pittsburgh, PA, USA