1. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD;
2. Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD;
3. Academic Model Providing Access to Healthcare (AMPATH), Eldoret, Kenya;
4. Department of Biostatistics, Brown University School of Public Health, Providence, RI; and
5. Moi University, School of Public Health, Eldoret, Kenya;