1. Department of Medicine, the University of Alabama at Birmingham, Birmingham, Alabama35294.
2. Department of Medicine, the University of Alabama at Birmingham, Birmingham, Alabama35294; Department of Epidemiology and International Health, the University of Alabama at Birmingham, Birmingham, Alabama35294; Department of Veterans Affairs Medical Center, Birmingham, Alabama 35233.
3. Department of Medicine, the University of Alabama at Birmingham, Birmingham, Alabama35294; Keck School of Medicine, University of Southern California, Los Angeles, California 90033
4. Department of Medicine, the University of Alabama at Birmingham, Birmingham, Alabama35294; Department of Epidemiology and International Health, the University of Alabama at Birmingham, Birmingham, Alabama35294.