Longer duration of homelessness is associated with a lower likelihood of non-detectable plasma HIV-1 RNA viral load among people who use illicit drugs in a Canadian setting

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.

Precarious Housing Associated with Unsuppressed Viral load, sub-optimal Access to HIV Treatment and Unmet Health care Needs, Among Women Living with HIV in Metro Vancouver, Canada

We investigated associations between (1) housing status (four categories measuring housing stability) and outcomes along the HIV care continuum (not currently on antiretroviral therapy [ART]; sub-optimal ART adherence [< 95% in the last 3-4 weeks]; unsuppressed viral load [> 200 copies/ml], median CD4 < 200 in the last six months), and (2) housing status and unmet primary, dental and mental health care needs in the last six months among WLWH. Housing status was defined according to the Canadian Definition of Homelessness and had four categories: unsheltered (i.e., living in ≥ 1 unsheltered location [e.g., street, abandoned buildings]), unstable (i.e., living in ≥ 1 unstable location [e.g., shelter, couch surfing]), supportive housing (i.e., only living in supportive housing), and stable housing (i.e., only living in one's own housing; reference). At baseline, in the last six months, 47.3% of participants reported unstable housing, followed by 24.4% unsheltered housing, 16.4% stable housing, and 11.9% supportive housing. Overall, 19.1% of the full sample (N = 336, 2010-2019) reported not currently on ART; among participants on ART, 28.0% reported sub-optimal ART adherence. Overall, 32.1% had recent unsuppressed viral load. Among a subsample (n = 318, 2014-2019), 15.7% reported unmet primary care needs, 26.1% unmet dental care needs, and 16.4% unmet mental health care needs. In adjusted models, being unsheltered (vs. stable housing) was associated with not currently on ART, unsuppressed viral load, and unmet primary and dental care needs. Housing and health services need to be developed with and for WLWH to address structural inequities and fulfill basic rights to housing and health.

The prevalence and social-structural correlates of housing status among women living with HIV in Vancouver, Canada

Background

Women living with HIV (WLWH) experience numerous social and structural barriers to stable housing, with substantial implications for access to health care services. This study is the first to apply the Canadian Definition of Homelessness (CDOH), an inclusive national guideline, to investigate the prevalence and correlates of housing status among WLWH in Metro Vancouver, Canada.

Methods

Our study utilized data from a longitudinal open cohort of cisgender and trans WLWH aged 14 years and older, in 2010–2019. Cross-sectional descriptive statistics of the prevalence of housing status and other social and structural variables were summarized for the baseline visits. Bivariate and multivariable logistic regression analyses were conducted using generalized linear mixed models (GLMM) for repeated measures to investigate the relationship between social and structural correlates and housing status among WLWH.

Results

The study included 336 participants with 1930 observations over 9 years. Housing status derived from CDOH included four categories: unsheltered, unstable, supportive housing, and stable housing (reference). Evidence suggested high levels of precarious housing, with 24% of participants reporting being unsheltered, 47% reporting unstable housing, 11.9% reporting supportive housing, and 16.4% reporting stable housing in the last six months at baseline. According to the multivariable models, living in the Downtown Eastside (DTES) neighbourhood of Metro Vancouver, hospitalization, physical/sexual violence, and stimulant use were associated with being unsheltered, compared to stable housing; DTES residence, hospitalization, and physical/sexual violence were associated with unstable housing; DTES residence and stimulant use were associated with living in supportive housing.

Conclusion

Complex social-structural inequities are associated with housing instability among WLWH. In addition to meeting basic needs for living, to facilitate access to housing among WLWH, housing options that are gender-responsive and gender-inclusive and include trauma- and violence-informed principles, low-barrier requirements, and strong connections with supportive harm reduction services are critical.

Periods of Homelessness Linked to Higher VACS Index Among HIV-Positive People Who Use Drugs

We sought to evaluate the impact of homelessness on HIV disease progression among people who use unregulated drugs (PWUD) living with HIV and test if this association was mediated by adherence to antiretroviral therapy (ART). We applied general linear mixed-effects modeling to estimate the longitudinal relationship between homelessness and the Veterans Aging Cohort Study (VACS) Index, a validated measure of HIV disease progression that predicts all-cause mortality, among a prospective cohort of PWUD. In a longitudinal model adjusted for ART adherence, homelessness was significantly associated with increased VACS Index scores and 16% of the association was mediated by ART adherence. These findings indicate that homelessness was a significant risk factor for HIV disease progression and this association was marginally mediated by ART adherence. Future studies are needed to quantify the other mechanisms (e.g., food insecurity, mental health) by which homelessness increases mortality risk among PWUD living with HIV.

The effect of homelessness on viral suppression in an underserved metropolitan area of middle Tennessee: potential implications for ending the HIV epidemic

BACKGROUND

A wealth of scientific evidence supports the effectiveness of HIV prophylaxis and treatment. Homelessness is strongly associated with the health status and viral suppression among underserved populations and can undermine the national plan to eliminate HIV by 2030. This retrospective observational study examined the extent in which homelessness affects HIV treatment in an underserved urban area of Middle Tennessee in 2014-2019.

RESULTS

Among 692 HIV-seropositive patients, the proportion of homeless patients increased from 13.5% in 2014 to 27.7% in 2019, thrice the national average for HIV-seropositive people (8.4%) and twice that of HIV positive patients who are participating in Ryan White programs nationwide (12.9%). Our findings suggest that homeless patients were half as likely to achieve viral suppression as compared to those who had a permanent/stable home [OR 0.48 (0.32-0.72), p-value < 0.001].

CONCLUSION

Our study indicates that homelessness may play an important role in viral suppression among persons living with HIV/AIDS in Middle Tennessee.

Unsafe Injection Is Associated with Higher HIV Testing after Bayesian Adjustment for Unmeasured Confounding

BACKGROUND

To apply a novel method to adjust for HIV knowledge as an unmeasured confounder for the effect of unsafe injection on future HIV testing.

METHODS

The data were collected from 601 HIV-negative persons who inject drugs (PWID) from a cohort in San Francisco. The panel-data generalized estimating equations (GEE) technique was used to estimate the adjusted risk ratio (RR) for the effect of unsafe injection on not being tested (NBT) for HIV. Expert opinion quantified the bias parameters to adjust for insufficient knowledge about HIV transmission as an unmeasured confounder using Bayesian bias analysis.

RESULTS

Expert opinion estimated that 2.5%-40.0% of PWID with unsafe injection had insufficient HIV knowledge; whereas 1.0%-20.0% who practiced safe injection had insufficient knowledge. Experts also estimated the RR for the association between insufficient knowledge and NBT for HIV as 1.1-5.0. The RR estimate for the association between unsafe injection and NBT for HIV, adjusted for measured confounders, was 0.96 (95% confidence interval: 0.89,1.03). However, the RR estimate decreased to 0.82 (95% credible interval: 0.64, 0.99) after adjusting for insufficient knowledge as an unmeasured confounder.

CONCLUSION

Our Bayesian approach that uses expert opinion to adjust for unmeasured confounders revealed that PWID who practice unsafe injection are more likely to be tested for HIV - an association that was not seen by conventional analysis.

Predictors of Antiretroviral Adherence Self-efficacy Among People Living With HIV/AIDS in a Canadian Setting

BACKGROUND

Suboptimal adherence to antiretroviral therapy (ART) among people living with HIV/AIDS (PLWHA) who use illicit drugs remains an ongoing health concern. Although health outcomes associated with adherence self-efficacy have been well-documented, there is dearth research exploring the predictors of this construct. This study sought to identify possible determinants of adherence self-efficacy among a cohort of PLWHA who use illicit drugs.

METHODS

From December 2004 to May 2014, we collected data from the AIDS Care Cohort to evaluate Exposure to Survival Services, a prospective cohort of adult PLWHA who use illicit drugs in Vancouver, Canada. We used multivariate generalized estimating equation analyses to identify longitudinal factors independently associated with higher adherence self-efficacy.

RESULTS

Among 742 participants, 493 (66.4%) identified as male and 406 (54.7%) reported white ancestry. In multivariate generalized estimating equation analysis, older age at ART initiation (adjusted odds ratio [AOR] = 1.02, 95% confidence interval [CI]: 1.00 to 1.03) and recent year of baseline interview (AOR = 1.08, 95% CI: 1.05 to 1.11) were independently associated with higher adherence self-efficacy, whereas homelessness (AOR = 0.78, 95% CI: 0.65 to 0.94), ≥daily crack smoking (AOR = 0.81, 95% CI: 0.68 to 0.96), experienced violence (AOR = 0.82, 95% CI: 0.69 to 0.98), and childhood abuse (AOR = 0.75, 95% CI: 0.60 to 0.92) were negatively associated.

CONCLUSIONS

These findings highlight the potential role that personal and contextual factors can play in predicting levels of ART adherence self-efficacy. Future research should seek to identify and validate strategies to optimize adherence self-efficacy.

Social and structural factors associated with greater time with a plasma HIV-1 RNA viral load above log10(1500) copies/ml among illicit drug users

OBJECTIVES

Although previous cross-sectional studies have identified correlates of detectable plasma HIV-1 RNA viral load (VL) among HIV-positive people who use drugs (PWUD), longitudinal factors associated with heightened HIV transmission potential have not been well described. Therefore, we longitudinally examined factors associated with amount of person-time spent above log10(1500) copies/ml plasma among HIV-positive PWUD in Vancouver, Canada.

DESIGN

Data were derived from a long-running prospective cohort of HIV-positive PWUD linked to comprehensive clinical records including systematic VL monitoring.

METHODS

We used generalized estimating equations modeling to longitudinally examine factors associated with person-time (in days) with a VL more than log10(1500) copies/ml plasma in the previous 180 days.

RESULTS

Between December 2005 and May 2014, 845 PWUD were eligible and included in the study. Participants spent an average of 26.8% of observation time with a VL more than log10(1500) copies/ml. In multivariable analyses, homelessness (Adjusted Rate Ratio [ARR] = 1.45) and lack of social support (ARR = 1.27) were positively associated with person-time with a VL more than log10(1500) copies/ml. Older age (ARR = 0.97) and enrolment in addiction treatment (ARR = 0.75) were negatively associated with the outcome in multivariable analyses (all P < 0.05).

CONCLUSION

Social and structural factors, including periods of homelessness or lacking in social support, were independently associated with greater amount of time with heightened HIV transmission potential. These findings suggest the need for targeted efforts to address modifiable contextual factors that contribute to increased risk of onward HIV transmission among PWUD.

Place-Based Predictors of HIV Viral Suppression and Durable Suppression Among Men Who Have Sex With Men in New York City

We explore relationships between place characteristics and HIV viral suppression among HIV-positive men who have sex with men (MSM) in New York City (NYC). We conducted multilevel analyses to examine associations of United Hospital Fund (UHF)-level characteristics to individual-level suppression and durable suppression among MSM. Individual-level independent and dependent variables came from MSM in NYC's HIV surveillance registry who had been diagnosed in 2009-2013 (N = 7159). UHF-level covariates captured demographic composition, economic disadvantage, healthcare access, social disorder, and police stop and frisk rates. 56.89% of MSM achieved suppression; 35.49% achieved durable suppression. MSM in UHFs where 5-29% of residents were Black had a greater likelihood of suppression (reference: ≥30% Black; adjusted relative risk (ARR) = 1.07, p = 0.04). MSM in UHFs with <30 MSM-headed households/10,000 households had a lower likelihood of achieving durable suppression (reference: ≥60 MSM-headed households/10,000; ARR = 0.82; p = 0.05). Place characteristics may influence viral suppression. Longitudinal research should confirm these associations.