We will use purposeful sampling to systematically represent subgroups of early disease adherers (both low and high) and create the conditions for in-depth qualitative analysis. Starting at 6 months of follow-up, we will identify from the larger cohorts of participants, 25 pregnant early disease adherers and 25 non-pregnant early disease adherers at each of the two (Ugandan and South African) study sites (total qualitative sample size = 100 individuals). Interviews with pregnant women may occur during the post-partum period. Each qualitative participant will take part in a single, in-depth individual interview conducted by a research assistant trained in the collection of in depth qualitative interviews. Interviews will target the actual adherence experiences and behavior of interviewees and systematically cover a range of relevant topics, including: (a) the circumstances under which pills are taken (dosing behavior); (2) missed doses and why they happened; (3) what obstacles impede adherence; (3) who helps with adherence and how (social support). Interviews will be transcribed into English, if needed, to produce the qualitative data set of 100 interview transcripts.