1. Department of Research & Evaluation Kaiser Permanente Southern California Pasadena California USA
2. Department of Health Systems Science Kaiser Permanente Bernard J. Tyson School of Medicine Pasadena California USA
3. Institute for Health Research Kaiser Permanente Colorado Aurora Colorado USA
4. Division of General Internal Medicine, Department of Medicine University of Colorado School of Medicine Aurora Colorado USA
5. Chemical Dependency Treatment Services Colorado Permanente Medical Group Aurora Colorado USA
6. Center for Clinical Epidemiology and Population Health Marshfield Clinic Research Institute Marshfield Wisconsin USA
7. Department of Epidemiology Colorado School of Public Health Aurora Colorado USA