# A survey weighted analysis of HPTN 071 (PopART) primary outcome of HIV incidence

## TL;DR

This study re-analyzed an HIV prevention trial in Zambia and South Africa to better estimate the impact of different interventions on reducing HIV incidence.

## Contribution

The study introduces a sample-weighted analysis to account for the sampling design in the PopART trial, providing a more accurate population-based estimate of the intervention effect.

## Key findings

- Arm B communities showed a 25% reduction in HIV incidence compared to standard of care.
- No significant difference in HIV incidence was found between Arm A communities and standard of care.
- The results align with the primary findings of the PopART trial.

## Abstract

HPTN 071 (PopART) implemented a comprehensive HIV prevention package which aimed to reduce HIV incidence within 21 communities of Zambia and South Africa: Arm A, PopART intervention of universal HIV testing and treatment; Arm B, PopART intervention of universal HIV testing with ART provided according to local guidelines; and Arm C, standard of care. Analyses so far have not accounted for the sampling design of the enrolled cohort. We performed a sample-weighted re-analysis of the primary outcome of the PopART trial to derive a population-based estimate of the intervention effect.

Enrollment used a two-stage sampling design: household and adult participant within each household. We constructed post-stratification weights to match the age and sex distribution of the target population in these communities. Weighted Poisson regression was used to estimate community-level HIV incidence. The PopART intervention effect was estimated using log-transformed community-level incidence estimates in an ANCOVA model.

The analysis based on community-level incidence shows a 25% reduction in incidence for Arm B communities compared to standard of care (RR: 0.75, 95% CI: 0.56–1.02, p = 0.06) while Arm A communities show no difference in HIV incidence compared to standard of care (RR: 1.08, 95% CI: 0.81–1.46, p = 0.56).

Our re-analysis shows 25% reduction in HIV incidence comparing Arm B to Arm C communities. No effect was observed comparing Arm A communities to Arm C communities. These results align with the primary results of the PopART trial.

ClinicalTrials.gov number, NCT01900977, HPTN 071 [PopArt].

The online version contains supplementary material available at 10.1186/s12981-025-00720-0.