Evaluating the impact of conditional micro-incentives on linkage to HIV care in rural South Africa: Results from the Home-Based Intervention to Test and Start (HITS) trial

Timely linkage from HIV diagnosis to care is critical for effective treatment and epidemic control. We evaluated the effectiveness of conditional micro-incentives on linkage to HIV care in the Home-Based Intervention to Test and Start (HITS) trial, a real-world implementation trial in rural South Africa. Of 45 communities in uMkhanyakude, KwaZulu-Natal, 16 were randomized to micro-incentive arms offering food vouchers (R50 [US$3]) conditional on completing home-based HIV counseling and testing (HBHCT) and linkage to care within 6 weeks, and 29 to non-incentive arms. All individuals were eligible for HBHCT, enrolled between February and December 2018, and followed for 1 year. The primary outcome was linkage to care at 1 year among men; secondary outcomes included linkage within the 6-week voucher eligibility among men and women, and at 1 year among women. Intention-to-treat analyses were performed using Poisson regression adjusted for study arms. Among 13,894 men and 19,884 women eligible for the study (aged ≥15 years), home-based testing uptake was 21% (n=2,867) and 29% (n=5,795), yielding 122 (4.3%) and 375 (6.5%) new diagnoses, respectively. Overall, micro-incentives nearly doubled HIV-positive diagnoses. Among men, micro-incentives did not increase linkage to care within 6 weeks (risk ratio [RR]=0.78, 95% CI: 0.51-1.21) or at 1 year (RR=1.08, 95% CI: 0.86-1.35). Among women, micro-incentives increased linkage to care within 6 weeks by 51% (RR=1.51; 95% CI: 1.03-2.21), with no residual impact at 1 year (RR=1.07, 95% CI: 0.91-1.26). In a hyper-endemic rural African setting, once-off micro-incentives can substantially increase early linkage to HIV care among women during the incentive eligibility period but are inadequate to significantly improve care engagement among men.