University of Washington, University of Nebraska at Omaha - Department of Internal Medicine, University of Nebraska Medical Center, VA Puget Sound Health Care System, VA Salt Lake City Health Care System, University of Washington, University of Nebraska at Lincoln - University of Nebraska Medical Center, VA Salt Lake City Health Care System, University of Nebraska Medical Center, affiliation not provided to SSRN, The National Databank for Rheumatic Diseases, University of California, San Francisco (UCSF) - Division of Rheumatology, VA Puget Sound Health Care System - Geriatric Research Education and Clinical Center, affiliation not provided to SSRN, University of Pennsylvania and University of Washington