1. University of California, San Diego; La Jolla CA USA
2. David Geffen School of Medicine at UCLA; Los Angeles CA USA
3. California Pacific Medical Center Research Institute and University of California, San Francisco; San Francisco CA USA
4. HealthPartners Institute and Division of Health Policy and Management; University of Minnesota; Minneapolis MN USA
5. Department of Epidemiology; Graduate School of Public Health; University of Pittsburgh; Pittsburgh PA USA
6. Oregon Health Sciences University; Portland OR USA