1 Department of Family and Community Medicine, Meharry Medical College, 1005 Dr D.B. Todd Boulevard, Nashville, TN 37208, USA. Electronic address: morellivincent@yahoo.com.
2 Family and Community Medicine, Baylor College of Medicine, 3701 Kirby Drive, Suite 600, Houston, TX 77098, USA. Electronic address: roger.zoorob@bcm.edu.