Objectives The HIV treatment cascade is a powerful framework for understanding progress from initial diagnosis to successful treatment. Data sources for cascades vary and often are based on clinical cohorts, population cohorts linked to clinics, or self-reported information. We use both biomarkers and self-reported data from a large population-based cohort of older South Africans to establish the first HIV cascade for this growing segment of the HIV-positive population and compare results using the different data sources.
Methods Data came from the Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa (HAALSI) 2015 baseline survey of 5059 adults aged 40+ years. Dried blood spots (DBS) were screened for HIV, antiretroviral drugs and viral load. In-home surveys asked about HIV testing, diagnosis and antiretroviral therapy (ART) use. We calculated proportions and CIs for each stage of the cascade, conditional on attainment of the previous stage, using (1) biomarkers, (2) self-report and (3) both biomarkers and self-report, and compared with UNAIDS 90-90-90 targets.
Results 4560 participants had DBS results, among whom 1048 (23%) screened HIV-positive and comprised the denominator for each cascade. The biomarker cascade showed 63% (95% CI 60 to 66) on ART and 72% (95% CI 69 to 76) of those on ART with viral suppression. Self-reports underestimated testing, diagnosis and ART, with only 47% (95% CI 44 to 50) of HIV-positive individuals reporting ART use. The combined cascade indicated high HIV testing (89% (95% CI 87 to 91)), but lower knowledge of HIV-positive status (71% (95% CI 68 to 74)).
Conclusions Older South Africans need repeated HIV testing and sustained ART to reach 90-90-90 targets. HIV cascades relying on self-reports are likely to underestimate true cascade attainment, and biomarkers provide substantial improvements to cascade estimates.
- antiretroviral therapy
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Handling editor Nicola Low
Contributors JKR, TB and JAS conceived and designed this analysis. KK, ST, JAS and TB were involved in the design of the HAALSI study. RGW, CK and FXG-O were involved in data collection for the study. JKR analysed the data and drafted the manuscript. JKR, JAS, TB, JM-G, FXG-O, MR and PG interpreted the data analysis. All authors were involved in reviewing the manuscript and approved the final manuscript. TB and JAS: joint last authorship.
Funding The HAALSI study is funded by the National Institute on Aging (NIA) of the National Institutes of Health (NIH) (P01-AG041710), and is nested within the MRC/Wits Rural Public Health and Health Transitions Research Unit (Agincourt), funded by Wellcome Trust (058893/Z/99/A; 069683/Z/02/Z; 085477/Z/08/Z; 085477/B/08/Z) with important contributions from the University of the Witwatersrand, and the South African Medical Research Council. TB was supported by the Alexander von Humboldt Foundation through the Alexander von Humboldt Professor award, funded by the German Federal Ministry of Education and Research, as well as by NICHD of NIH (R01-HD084233), NIA of NIH (P01-AG041710), NIAID of NIH (R01-AI124389 and R01-AI112339) and FIC of NIH (D43-TW009775).
Competing interests None declared.
Patient consent for publication Not required.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement Data are available in a public, open-access repository.
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