1. Department of Epidemiology and Community Health, Virginia Commonwealth University, Richmond, Virginia.
2. Department of Epidemiology, Brown University, Providence, Rhode Island.
3. Center for Primary Care and Prevention, Memorial Hospital of Rhode Island, Pawtucket, Rhode Island.
4. Department of Family Medicine, Warren Alpert Medical School, Brown University, Providence, Rhode Island.
5. Department of Rheumatology Tufts Medical School, Boston, Massachusetts.