1. Division of Research; Kaiser Permanente; Oakland; CA; USA
2. Division of Rheumatology, Department of Medicine; University of Massachusetts Medical School, Meyers Primary Care Institute; Worcester; MA; USA
3. Institute for Health Research; Kaiser Permanente Colorado; Denver; CO; USA
4. Department of Pulmonology; Oakland Medical Center, Kaiser Permanente; Oakland; CA; USA
5. Divisions of Infectious Diseases, and Public Health and Preventive Medicine; Oregon Health and Sciences University; Portland; OR; USA
6. Division of Rheumatology, Division of Pharmacoepidemiology; Brigham and Women's Hospital; Boston; MA; USA
7. UAB Center for Education and Research in Therapeutics of Musculoskeletal Disorders; University of Alabama at Birmingham; Birmingham; AL; USA
8. Department of Medicine, Department of Biostatistics and Epidemiology; University of Pennsylvania; Philadelphia; PA; USA