Massachusetts General Hospital Cancer Center, Boston, Massachusetts, United States
Kaiser Permanente - Aurora, Aurora, Colorado, United States
Harvard Pilgrim Health Care, Boston, Massachusetts, United States
Oregon Research Institute, Eugene, Oregon, United States
Kaiser Permanente - Aurora, Aurora, Colorado, United States
Kaiser Permanente Center for Health Research, Portland, Oregon, United States
Health Partners, Minneapolis, Minnesota, United States
Kaiser Permanent Center for Health Research, Portland, Oregon, United States
Harvard Pilgrim Healthcare, Boston, Massachusetts, United States
Kaiser Permanente Center for Health Research, Portland, Oregon, United States
Group Health Cooperative, Center for Health Studies, Seattle, Washington, United States
VA Puget Sound Health Care System, Seattle, Washington, United States
Group Health Research Institute, Seattle, Washington, United States
Group Health Cooperative, Seattle, Washington, United States
Group Health Research Institute, Seattle, Washington, United States
Group Health Research Institute, Seattle, Washington, United States
Kaiser Permanente Center for Health Research, Portland, Oregon, United States