Evidence of sociodemographic heterogeneity across the HIV treatment cascade and progress towards 90-90-90 in sub-Saharan Africa - a systematic review and meta-analysis

Abstract

Introduction: Heterogeneity of sociodemographics and risk behaviours across the HIV treatment cascade could influence the public health impact of universal ART in sub-Saharan Africa if those not virologically suppressed are more likely to be part of a risk group contributing to onward infections. Sociodemographic and risk heterogeneity across the treatment cascade has not yet been comprehensively described or quantified and we seek to systematically review and synthesize research on this topic among adults in Africa.

Methods: We conducted a systematic review of peer-reviewed literature in Embase and MEDLINE databases as well as grey literature sources published in English between 2014 and 2018. We included studies that included people living with HIV (PLHIV) aged ≥15 years, and reported a 90-90-90 outcome: awareness of HIV-positive status, ART use among those diagnosed or viral suppression among those on ART. We summarized measures of association between sociodemographics, within each outcome, and as a composite measure of population-wide viral suppression.

Results and discussion: From 3533 screened titles, we extracted data from 92 studies (50 peer-reviewed, 42 grey sources). Of included studies, 32 reported on awareness, 53 on ART use, 32 on viral suppression and 23 on population-wide viral suppression. The majority of studies were conducted in South Africa, Uganda, and Malawi and reported data for age and gender. When stratified, PLHIV ages 15 to 24 years had lower median achievement of the treatment cascade (60-49-81), as compared to PLHIV ≥25 years (70-63-91). Men also had lower median achievement of the treatment cascade (66-72-85), compared to women (79-76-89). For population-wide viral suppression, women aged ≥45 years had achieved the 73% target, while the lowest medians were among 15- to 24-year-old men (37%) and women (49%).

Conclusions: Considerable heterogeneity exists by age and gender for achieving the HIV 90-90-90 treatment goals. These results may inform delivery of HIV testing and treatment in sub-Saharan Africa, as targeting youth and men could be a strategic way to maximize the population-level impact of ART.

Keywords: 90-90-90; HIV testing; antiretroviral treatment; cascade; sub-Saharan Africa; sustained virologic response.

Figure 1

Flow diagram of included studies. PHIA, Population‐based HIV impact assessment.

Figure 2

Number of studies by country. Blue gradation reflects number of included studies set in each country, pink colour represents sub‐Sahara African countries with no included data and grey reflects non‐sub‐Saharan countries.

Figure 3

Number of studies which reported each variable and reported a measure of association by each variable. Variable Reported in Study Characteristics reflects the number of included studies which reported the accompanying sociodemographic or risk behaviour data. Measure of Association by Variable represents the number of studies where the sociodemographic or risk behaviour data were analysed by an outcome of interest, that is, an odds ratio or disaggregated count data.

Figure 4

Percentage achieving Awareness of HIV‐positive Status, ART Use, Viral Suppression and Population‐wide Viral Suppression (PWVS) by age group (A) and by gender (B). Data in box plots reflect individual studies and are a distribution of study estimates. Results are not weighted by sample size or sampling design, and therefore medians and interquartile ranges and do not represent unbiased estimates of the outcomes for the underlying target populations. Red dashed line represents UNAIDS’ 90% goal for Awareness of HIV‐Positive Status, ART Use, and Viral Suppression, and 73% goal for Population‐wide Viral Suppression. Note that the first three sets of bars in each figure are conditioned on the previous bar, while PWVS is an aggregate estimate. For age, 57% of studies were cross‐sectional, 14% cohort, 21% RCT and 7% case‐control. By gender, 72% are cross‐sectional, 16% are cohort, 9% RCT and 3% are case‐control.

Figure 5

Percentage of population achieving viral suppression by age group and gender. Only PHIA and South African National HIV Prevalence, Incidence, Behaviour, and Communication Survey are included, as they had similar population‐based sampling designs and presented data stratified by similar age bands and gender. Data in box plots reflect individual studies and are a distribution of study estimates. Results are not weighted by sample size or sampling design, and therefore medians and interquartile ranges and do not represent unbiased estimates of the outcomes for the underlying target populations. Red dashed line represents UNAIDS’ 90% goal for Awareness of HIV‐positive Status, ART Use and Viral Suppression, and 73% goal for Population‐wide Viral Suppression.