[1] Johns Hopkins Bloomberg Sch Publ Hlth, Dept Epidemiol, Baltimore, MD USA
[2] Moi Univ, Coll Hlth Sci, Sch Med, Behav Sci Dept, Eldoret, Kenya
[3] Acad Model Providing Access Healthcare AMPATH Part, Eldoret, Kenya
[4] Moi Univ, Coll Hlth Sci, Sch Med, Mental Hlth Dept, Eldoret, Kenya
[5] Univ Toronto, Dalla Lana Sch Publ Hlth, Div Epidemiol, Toronto, ON, Canada
[6] Moi Univ, Coll Hlth Sci, Sch Publ Hlth, Dept Epidemiol & Med Stat, Eldoret, Kenya
[7] Brown Univ, Dept Behav & Social Sci, Sch Publ Hlth, Providence, RI USA
[8] Univ North Carolina Chapel Hill, Dept Epidemiol, Mc Gavran Greenberg Hall, Chapel Hill, NC 27516 USA