HIV Treatment Cascade by Housing Status at Enrollment: Results from a Retention in Care Cohort

Statistical methods applied for the assessment of the HIV cascade and continuum of care: a systematic scoping review

OBJECTIVES

This scoping review aims to identify and synthesise existing statistical methods used to assess the progress of HIV treatment programmes in terms of the HIV cascade and continuum of care among people living with HIV (PLHIV).

DESIGN

Systematic scoping review.

DATA SOURCES

Published articles were retrieved from PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL) Complete and Excerpta Medica dataBASE (EMBASE) databases between April and July 2022. We also strategically search using the Google Scholar search engine and reference lists of published articles.

ELIGIBILITY CRITERIA

This scoping review included original English articles that estimated and described the HIV cascade and continuum of care progress in PLHIV. The review considered quantitative articles that evaluated either HIV care cascade progress in terms of the Joint United Nations Programme on HIV and AIDS targets or the dynamics of engagement in HIV care.

DATA EXTRACTION AND SYNTHESIS

The first author and the librarian developed database search queries and screened the retrieved titles and abstracts. Two independent reviewers and the first author extracted data using a standardised data extraction tool. The data analysis was descriptive and the findings are presented in tables and visuals.

RESULTS

This review included 300 articles. Cross-sectional study design methods were the most commonly used to assess the HIV care cascade (n=279, 93%). In cross-sectional and longitudinal studies, the majority used proportions to describe individuals at each cascade stage (276/279 (99%) and 20/21 (95%), respectively). In longitudinal studies, the time spent in cascade stages, transition probabilities and cumulative incidence functions was estimated. The logistic regression model was common in both cross-sectional (101/279, 36%) and longitudinal studies (7/21, 33%). Of the 21 articles that used a longitudinal design, six articles used multistate models, which included non-parametric, parametric, continuous-time, time-homogeneous and discrete-time multistate Markov models.

CONCLUSIONS

Most literature on the HIV cascade and continuum of care arises from cross-sectional studies. The use of longitudinal study design methods in the HIV cascade is growing because such methods can provide additional information about transition dynamics along the cascade. Therefore, a methodological guide for applying different types of longitudinal design methods to the HIV continuum of care assessments is warranted.

Experiencing homelessness and progression through the HIV cascade of care among people who use drugs

OBJECTIVE

To investigate the longitudinal association between periods of homelessness and progression through the HIV cascade of care among people who use drugs (PWUD) with universal access to no-cost HIV treatment and care.

DESIGN

Prospective cohort study.

METHODS

Data were analysed from the ACCESS study, including systematic HIV clinical monitoring and a confidential linkage to comprehensive antiretroviral therapy (ART) dispensation records. We used cumulative link mixed-effects models to estimate the longitudinal relationship between periods of homelessness and progression though the HIV cascade of care.

RESULTS

Between 2005 and 2019, 947 people living with HIV were enrolled in the ACCESS study and 304 (32.1%) reported being homeless at baseline. Homelessness was negatively associated with overall progression through the HIV cascade of care [adjusted partial proportional odds ratio (APPO) = 0.56, 95% confidence interval (CI): 0.49-0.63]. Homelessness was significantly associated with lower odds of progressing to each subsequent stage of the HIV care cascade, with the exception of initial linkage to care.

CONCLUSIONS

Homelessness was associated with a 44% decrease in the odds of overall progression through the HIV cascade of care, and a 41-54% decrease in the odds of receiving ART, being adherent to ART and achieving viral load suppression. These findings support calls for the integration of services to address intersecting challenges of HIV, substance use and homelessness among marginalized populations such as PWUD.

Molecular Epidemiology of Individuals Experiencing Unstable Housing or Living Homeless at HIV Diagnosis: Analysis of HIV Surveillance Data in King County, Washington

We examined patterns of genetic clustering among individuals diagnosed with HIV between 2010 and 2018 using data from King County, Washington's National HIV Surveillance System. Among 2,371 individuals newly diagnosed with HIV, 231 (10%) experienced unstable housing or were living homeless at the time of diagnosis. Among the 1,658 (70%) people with an available HIV-1 pol gene sequence, 1,071 (65%) were identified to be part of 296 genetic clusters. In our analysis, housing status was not associated with genetic clustering (OR 1.02; 95%CI:0.75,1.39). After adjusting for demographic and behavioral factors, people who were living homeless at HIV diagnosis had 35% lower odds of being identified as part of a genetic cluster (AOR 0.65; 95%CI:0.44,0.95) compared to people with stable housing. Our findings highlight that people experiencing unstable housing are disproportionately burdened by HIV, and that within this population in King County, being in a genetic cluster is predominantly associated with substance use.

Understanding disparities in viral suppression among Black MSM living with HIV in Atlanta Georgia

INTRODUCTION

Due to factors associated with structural racism, Black men who have sex with men (MSM) living with HIV are less likely to be virally suppressed compared to white MSM. Most of these data come from clinical cohorts and modifiable reasons for these racial disparities need to be defined in order to intervene on these inequities. Therefore, we examined factors associated with racial disparities in baseline viral suppression in a community-based cohort of Black and white MSM living with HIV in Atlanta, GA.

METHODS

We conducted an observational cohort of Black and white MSM living with HIV infection in Atlanta. Enrolment occurred from June 2016 to June 2017 and men were followed for 24 months; laboratory and behavioural survey data were collected at 12 and 24 months after enrolment. Explanatory factors for racial disparities in viral suppression included sociodemographics and psychosocial variables. Poisson regression models with robust error variance were used to estimate prevalence ratios (PR) for Black/white differences in viral suppression. Factors that diminished the PR for race by ≥5% were considered to meaningfully attenuate the racial disparity and were included in a multivariable model.

RESULTS

Overall, 26% (104/398) of participants were not virally suppressed at baseline. Lack of viral suppression was significantly more prevalent among Black MSM (33%; 69/206) than white MSM (19%; 36/192) (crude Prevalence Ratio (PR) = 1.6; 95% CI: 1.1 to 2.5). The age-adjusted Black/white PR was diminished by controlling for: ART coverage (12% decrease), housing stability (7%), higher income (6%) and marijuana use (6%). In a multivariable model, these factors cumulatively mitigated the PR for race by 21% (adjusted PR = 1.1 [95% CI: 0.8 to 1.6]).

CONCLUSIONS

Relative to white MSM, Black MSM living with HIV in Atlanta were less likely to be virally suppressed. This disparity was explained by several factors, many of which should be targeted for structural, policy and individual-level interventions to reduce racial disparities.

Time-space constraints to HIV treatment engagement among women who use heroin in Dar es Salaam, Tanzania: A time geography perspective

Timely initiation and sustained adherence to antiretroviral therapy (ART) are essential to improving the health outcomes of people living with HIV and preventing onward HIV transmission. However, women who use heroin often face challenges to initiating and adhering to ART. In this paper we identify spatial, temporal, and social factors that affect HIV treatment engagement among women who use heroin, drawing from a time geography framework. We conducted in-depth interviews with 30 heroin-using women living with HIV in Dar es Salaam, Tanzania between January and March 2019. We found that unstable housing, high mobility, HIV-related stigma, and unpredictable daily paths due to heroin use and involvement in sex work spatially and temporally constrained women who use heroin from incorporating HIV treatment behaviors into daily routines. Some women, however, were able to overcome these time-space constraints to HIV treatment engagement through social support and social role performance. Time geography, including concepts of time-space constraints and daily paths, is a useful framework for identifying barriers to ART engagement. Structural, relational, and individual interventions aimed at eliminating time-space constraints hold the potential to improve HIV treatment engagement among particularly vulnerable and mobile populations.