Browsing by Author "Zhou, Siyanai"

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    Age-specific all-cause mortality rates among adolescents and youth living with and without HIV: evidence from a cohort study in South Africa
    (John Wiley and Sons Inc, 2025) Knight, Lucia; Zhou, Siyanai; Toska, Elona
    Introduction: Mortality among adolescents living with HIV (ALHIV) remains a global health problem. We lack granular (age- and sex-disaggregated) data on mortality among ALHIV, hence, this study aims to assess all-cause mortality among ALHIV in a low-resource setting. Methods: All adolescents ever initiated on antiretroviral treatment (ART, N = 1107) and their HIV-negative peers (N = 456) aged 10–19 years, recruited as part of the Mzantsi Wakho study cohort, were followed up between 2014 and 2022 (yielding 12,427.7 person-years of follow-up). First, we assessed the proportion of deaths and estimated crude mortality incidence rates per 100 person-years of follow-up and their 95% confidence intervals, stratified by HIV status, sex and mode of HIV acquisition (vertical vs. sexual). We then estimated adjusted incidence rate ratios (IRRs) using Poisson regression adjusted for time-varying age, sex and time on ART. Last, we used the Cox proportional hazards regression model to estimate the risk of death by ART adherence. Results: A total of 1563 adolescents and young people were included in this analysis, 70.8% ALHIV and 57% female. More deaths occurred in ALHIV compared to their HIV-negative peers (8.3% vs. 0.4%, p<0.001). Among ALHIV, we observed a significantly higher proportion of deaths among males compared to females (10.7% vs. 7.1%, p = 0.036). Overall, mortality increased significantly with age, and males had a higher risk of mortality compared to females. Adolescents and youth living with vertically acquired HIV had a higher risk of mortality than those living with sexually acquired HIV. Comparing mortality rates by mode of HIV acquisition stratified by age and sex, mortality risk was higher among females aged 20+ years with vertically acquired HIV (IRR: 3.61, 95% CI 1.48–8.82) compared to females with sexually acquired HIV of the same age group. In a sub-sample analysis, sustained ART adherence was associated with a lower risk of death (aHR: 0.44, 95% CI 0.23–0.85).
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    Exploring self-reported adherence measures to screen for elevated HIV viral load in adolescents: A South African cohort study
    (Springer, 2023) Zhou, Siyanai; Toska, Elona; Knight, Lucia
    The timely identification of ART non-adherence among adolescents living with HIV presents a significant challenge, particularly in resource-limited settings where virologic monitoring is suboptimal. Using South African adolescent cohort data (N = 933, mean age 13.6 ± 2.89 years, 55.1% female, follow-up = 2014–2018), we examined the association between elevated viral load (VL ≥ 1000 copies/mL) and seven self-reported adherence measures on missed doses, and clinic appointments –with varying recall timeframes. The best performing measures, which were significantly associated with elevated viral load in covariate-adjusted models are: any missed dose –past 3 days (sensitivity = 91.6% [95%CI: 90.3–92.8], positive predictive value (PPV) = 78.8% [95%CI: 77.2–80.4]), –past week (sensitivity = 87% [95%CI: 85.4–88.6], PPV = 78.2% [95%CI: 76.5–79.9]), –past month (sensitivity = 79.5% [95%CI: 77.5–81.4], PPV = 78.2% [95%CI: 76.4–79.9]), any pastmonth days missed (sensitivity = 86.7% [95%CI: 85.1–88.3], PPV = 77.9% [95%CI:76.2–79.6]), and any missed clinic appointment (sensitivity = 88.3% [95%CI: 86.8–89.8], PPV = 78.4% [95%CI: 76.8–79.9]).
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    Longitudinal trajectories of antiretroviral treatment adherence and associations with durable viral suppression among adolescents living with HIV in South Africa
    (Wolters Kluwer Health, Inc., 2024) Zhou, Siyanai; Cluver, Lucie; Knight, Lucia
    Background: Compared with other age groups, adolescents living with HIV (ALHIV) are estimated to have lower levels of adherence to antiretroviral treatment. Despite this, we lack evidence on adolescents’ adherence patterns over time to inform the customization\of intervention strategies.Setting: Eastern Cape province, South Africa. Methods: We analyzed data from a cohort of ALHIV (N = 1046, aged 10–19 years at baseline) recruited from 53 public health facilities. The cohort comprised 3 waves of data collected between 2014 and 2018 and routine viral load data from the National Institute for Communicable Disease data warehouse (2014–2019). Durable viral suppression was defined as having suppressed viral load (,1000 copies/mL) at $2 consecutive study waves. Group-based multitrajectory model was used to identify adherence trajectories using 5 indicators of self-reported adherence. Logistic regression modeling evaluated the associations between adherence trajectories and durable viral suppression. Results: Overall, 933 ALHIV (89.2%) completed all 3 study waves (55.1% female, mean age: 13.6 years at baseline). Four adherence trajectories were identified, namely, “consistent adherence”(49.8%), “low start and increasing” (20.8%), “gradually decreasing” (23.5%), and “low and decreasing” (5.9%). Adolescents experiencing inconsistent adherence trajectories were more, likely to be older, live in rural areas, and have sexually acquired HIV. Compared with the consistent adherence trajectory, the odds of durable viral suppression were lower among adolescents in the low start and increasing (adjusted odds ratio [aOR]: 0.62, 95% CI: 0.41 to 0.95), gradually decreasing (aOR: 0.40, 95% CI: 0.27 to 0.59), and the low and decreasing adherence (aOR: 0.25, 95% CI: 0.10 to 0.62) trajectories. Conclusions: Adherence to antiretroviral treatment remains a challenge among ALHIV in South Africa. Identifying adolescents at risk of nonadherence, based on their adherence trajectories may inform the tailoring of adolescent-friendly support strategies.