The right combination – treatment outcomes among HIV-positive patients initiating first-line fixed-dose antiretroviral therapy in a public sector HIV clinic in Johannesburg, South Africa

Background Long-term antiretroviral therapy (ART) adherence is critical for achieving optimal HIV treatment outcomes. Fixed-dose combination (FDC) single-pill regimens, introduced in South Africa in April 2013, has simplified pill taking. We evaluated treatment outcomes among patients initiated on a FDC compared to a similar multi-pill ART regimen in Johannesburg, South Africa. Methods We conducted a retrospective cohort study of ART-naïve HIV-positive non-pregnant adult (≥18 years) patients without tuberculosis who initiated first-line ART on tenofovir and emtricitabine or lamivudine with efavirenz at Themba Lethu Clinic in Johannesburg, South Africa. We compared those initiated on a multi-pill ART regimen (3-5 pills/day; September 1, 2011-August 31, 2012) to those initiated on a FDC ART regimen (one pill/day; September 1, 2013-August 31, 2014). Treatment outcomes included attrition (combination of lost to follow-up and mortality), missed medical visits, and virologic suppression (viral load <400 copies/mL) by 12 months post-ART initiation. Cox proportional hazards models and Poisson regression were used to estimate the association between FDCs vs multiple pills and treatment outcomes. Results We included 3151 patients in our analysis; 2230 (70.8%) patients initiated multi-pill ART and 921 (29.2%) patients initiated on a FDC. By 12 months post-initiation, attrition (adjusted hazard ratio: 0.98; 95% CI: 0.77-1.24) was similar across regimen types (FDC vs multi-pill). Although not significant, patients on a FDC were marginally more likely to achieve viral suppression by 6 (adjusted relative rate [aRR]: 1.10; 95% CI: 0.99-1.23) and 12 months (aRR: 1.12; 95% CI: 0.92-1.36) on ART. Patients initiated on a FDC were significantly less likely to miss medical visits during the first 12 months of treatment (aRR: 0.66; 95% CI: 0.52-0.83). Conclusion Our results suggest FDCs may have a role to play in supporting patient adherence and medical monitoring through improved medical visit attendance. This may potentially improve treatment outcomes later on in treatment.