The impact of WHO Treat All guideline on disease progression among people enrolled in HIV care in Central Africa: an observational cohort data by target trial design with multistate modeling

WHOs Treat All guidelines, which eliminate eligibility thresholds for people living with HIV to receive antiretroviral therapy, have been implemented by most countries. However, the impact of Treat All on the process of HIV disease progression is unknown. We conducted a target trial to emulate a hypothetical RCT to evaluate the policys impact on HIV disease progression among people living with HIV. We included people enrolled in HIV care during 2013-2019 from the Central Africa International Epidemiology Databases to Evaluate AIDS. Multistate models inferred the transitional hazards of disease progression across the four WHO clinical stages (1: asymptomatic; 2: mild; 3: advanced; 4: severe) and death. We estimated hazard ratios (HR) between a cohort enrolling in HIV care after (n=4,607) and a cohort enrolling before (n=4,439) Treat All guideline implementation, with and without covariates adjustment. Treat All implementation was associated with decreased hazards of transition in most stage categories, with significant results from stage 1 to stage 2 (adjusted HR (aHR) 0.64, 95% CI 0.44-0.94) and from stage 1 to death (0.37, 0.17-0.81), and non-significant but low HR results from stage 2 to 3 (0.71, 0.50-1.01), from stage 2 to death (0.58, 0.18-1.80). Treat All implementation substantially reduced HIV disease progression. Main Point SummaryWe compared the HIV disease progression outcome between a pri- and post-Treat All periods, utilizing individual service delivery data from Central Africa International Epidemiology Databases to Evaluate AIDS. We concluded that Treat All implementation substantially reduced HIV disease progression.