Helen B Powell1, Adewole S Adamson2. 1. School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. 2. Department of Dermatology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Cecil G. Sheps Center for Health Services Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. Electronic address: adewole@med.unc.edu.