Affiliation: | 1. University of Alabama at Birmingham, Division of Clinical Immunology and Rheumatology, , Birmingham, AL, USA;2. University of Alabama at Birmingham, Epidemiology, , Birmingham, AL, USA;3. School of Public Health, University of Alabama at Birmingham, Department of Health Care, Organization and Policy, , Birmingham, AL, USA;4. Center for Clinical Epidemiology and Biostatistics, Perelman School of Medicine at the University of Pennsylvania, , Philadelphia, PA, USA |