1. Department of Epidemiology; Harvard School of Public Health; Boston MA USA
2. Department of Population Medicine; Harvard Medical School and Harvard Pilgrim Health Care Institute; Boston MA USA
3. Meyers Primary Care Institute/University of Massachusetts Medical School; Worcester MA USA
4. Vanderbilt University School of Medicine; Nashville TN USA
5. Center for Health Research; Southeast Kaiser Permanente Georgia; Atlanta GA USA
6. Group Health Research Institute; Seattle WA USA
7. Center for Drug Evaluation and Research; Food and Drug Administration; Silver Spring MD USA
8. HealthPartners Institute for Education and Research; Bloomington MN USA
9. Institute for Health Research; Kaiser Permanente Colorado; Denver CO USA
10. Center for Health Research; Kaiser Permanente Northwest; Portland OR USA