1. a Rollins School of Public Health, Department of Behavioral Sciences and Health Education , Emory University , Atlanta , GA , USA
2. b Department of Behavioral Science, Center on Drug and Alcohol Research , University of Kentucky College of Medicine , Lexington , KY , USA
3. c Department of Infectious Diseases , Wake Forest University School of Medicine , Winston-Salem , NC , USA
4. d Department of Social Sciences and Health Policy , Wake Forest University School of Medicine , Winston-Salem , NC , USA