Abstract
We estimate the effectiveness of antiretroviral therapy (ART) among individuals receiving HIV care in Rio de Janeiro, Brazil. Adults (18y+) initiating ART between Jan/2008 and Dec/2018 (follow-up through Dec/2020) were included. First-line ART (two nucleoside reverse transcriptase inhibitors plus one antiretroviral from another class) was categorized into four categories: non-nucleoside reverse transcriptase inhibitor/NNRTI-based, protease inhibitor/PI-based, integrase strand transfer inhibitor/INSTI-based, and single-tablet regimen (STR, Tenofovir 300mg + Lamivudine 300mg + Efavirenz 600mg). Effectiveness (viral load ≤50 copies/µL) was evaluated at 6(3-9) and 12(9-15) months from ART initiation. Bayesian logistic regression models were used to quantify the association between exposure and outcomes while accounting for missing data. Overall, 1863(57%), 652(19.9%), 412(12.6%), and 342(10.5%) individuals used, respectively, NNRTI-based, PI-based, INSTI-based regimens, and STR. Compared to NNRTIs, the odds of viral suppression with INSTI-based regimens was 76% higher (adjusted OR:1.76, 95%CI:1.23-2.51) at six months but no higher at 12 months. Older age, higher education, CD4 count ≥500 cells/mm(3) and viral load <100,000 copies/µL at ART initiation increased the odds of viral suppression. Viral suppression at six months was the strongest predictor of viral suppression at 12 months. These results highlight population groups that could benefit from close monitoring during the first year of ART.