Drivers of disengagement from care during the first six months on antiretroviral therapy for HIV in South Africa: A mixed-methods study.

For clients on HIV treatment in sub-Saharan Africa, early disengagement from care is a critical obstacle to achieving UNAIDS's second 95 target. While South Africa's Differentiated Service Delivery Guideline on Fast Track Initiation and Counseling (FTIC) defines normative procedures, the impact of implementation and drivers of disengagement remain unclear. The PREFER mixed-methods study enrolled a prospective cohort of adult clients initiating ART, returning to care after disengagement, or on ART for ≤6 months at 18 public healthcare facilities in South Africa. A survey collected demographic, clinical, and preference data. Participants were followed for up to 7 months using routinely collected medical records to estimate continuity of care (attendance at all scheduled visits within 28 days). Focus group discussions (FGDs) were conducted 12 months post-enrollment among participants who had expressed concerns about retention. A content analysis was conducted; emergent themes were situated within the Socio-Ecological Model framework. During the study period 7/9/2022-30/6/2023, PREFER-SA enrolled 1,049 participants (72% female, median age 33 years, 24% with CD4 < 200 cells/mm³); 122 also joined FGDs. By 6 months on ART, 23% were not continuously in care. New ART initiators were more likely to experience treatment interruption than those already retained for ≥1 visit. Disengagement was more likely among men, younger clients (18-24 years), those reporting food insecurity, and those not initiated on dolutegravir regimens. No differences were observed by relationship status, CD4 count or preferences for HIV care. FGDs revealed barriers to retention across all levels of the SEM, especially related to facility experience. Among adults initiating or re-initiating ART in South Africa, the highest risk of disengagement occurs immediately after initiation. Several potentially modifiable individual and social factors were associated with early disengagement. Strengthening implementation of South Africa's Service Delivery Guidelines and improving facility experiences may support better retention in early treatment.