1. Department of Preventive Medicine and Community Health, University of Texas Medical Branch, Galveston, TX
2. Community Health Services, University of Texas Medical Branch, Galveston, TX
3. Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX
4. Department of Medicine, Emory University School of Medicine, Atlanta, GA
5. Department of Epidemiology and Biostatistics, University of Texas Health Science Center, San Antonio, TX
6. Department of Medicine, University of California at San Francisco, San Francisco, CA