Abstract
INTRODUCTION: The World Health Organization's Treat All guidelines, which eliminate eligibility thresholds for initiating antiretroviral therapy (ART) among people living with HIV, have been implemented by most countries. However, how Treat All relates to the clinical progression of HIV disease across stages remains less well characterized. METHODS: We applied a target trial-inspired design to examine the association between Treat All policy implementation and HIV disease progression in the Central Africa region of the International Epidemiology Databases to Evaluate AIDS (IeDEA). The analysis included individuals enrolled in HIV care between 2013 and 2019. Using continuous-time multistate models, we estimated transition-specific hazards across four WHO clinical stages (1: asymptomatic; 2: mild; 3: advanced; 4: severe) and death. Disease progression was compared between individuals enrolling after (n = 4607) versus before (n = 4439) Treat All adoption, with hazard ratios (HRs) estimated with and without covariate adjustment. RESULTS: At enrollment, the distribution of WHO clinical stage in the Treat All cohort was 63.4% asymptomatic, 17.7% mild, 15.6% advanced, and 3.3% severe, compared with 59.1%, 18.3%, 19.0%, and 3.6%, respectively, in the pre-Treat All cohort. Treat All implementation was associated with lower hazards of disease progression for early-stage transitions. Specifically, reduced hazards were observed for transitions from stage 1 to stage 2 (adjusted HR [aHR] 0.64, 95% CI: 0.44-0.94) and from stage 1 directly to death (aHR 0.37, 95% CI: 0.17-0.81). Estimates for transitions originating from later disease stages were less precise, and no statistically significant differences were observed. CONCLUSIONS: Enrollment in HIV care following Treat All policy adoption was associated with reduced early-stage disease progression and mortality, suggesting more favorable disease-progression dynamics among individuals entering care in the Treat All era. These findings complement existing evidence on ART uptake and viral suppression and support the role of universal ART initiation in routine HIV care.