1. Division of Research; Kaiser Permanente; Oakland; CA; USA
2. UAB Center for Education and Research and Therapeutics of Musculoskeletal Disorders; University of Alabama at Birmingham; Birmingham; AL; USA
3. Department of Rheumatology, Department of Medicine, University of Massachusetts Medical School; Meyers Primary Care Institute and Fallon Clinic; Worcester; MA; USA
4. Institute for Health Research; Kaiser Permanente Colorado; Denver; CO; USA
5. Departments of Preventive Medicine and Medicine, Vanderbilt University School of Medicine and the Mid-South Geriatric Research Education and Clinical Center; Veterans Administration Tennessee Valley Health Care System; Nashville; TN; USA
6. Division of Rheumatology, Division of Pharmacoepidemiology; Brigham and Women's Hospital; Boston; MA; USA
7. Department of Medicine, Department of Biostatistics and Epidemiology; University of Pennsylvania; USA