1. Kaiser Permanente Washington Health Research Institute, Seattle
2. Department of Health Services, University of Washington, Seattle
3. Center for the Clinical Trials Network, National Institute on Drug Abuse, National Institutes of Health, Bethesda, Maryland
4. Division of Research, Kaiser Permanente Northern California, Oakland, California
5. Center of Excellence in Substance Addiction Treatment and Education, Veteran Affairs Puget Sound Health Care System, Seattle, Washington
6. Kaiser Permanente Colorado Institute for Health Research and Colorado Permanente Medical Group, Denver