1. Center for Health Research, Kaiser Permanente Northwest, Portland, Oregon, USA.
2. Department of Family Medicine, University of Washington, Seattle, Washington, USA.
3. Oregon Rural Practice-Based Research Network, Oregon Health & Science University, Portland, Oregon, USA.
4. Department of Psychiatry, University of Washington, Seattle, Washington, USA.
5. Kaiser Permanente Washington Health Research Institute, Seattle, Washington, USA.
6. Family Medicine, Washington Permanente Medical Group, Seattle, Washington, USA.