High-intensity Drug Use Research Articles

Drug‐related harm coinciding with income assistance payments: results from a community‐based cohort of people who use drugs

Income assistance is critical to the health and wellbeing of socio-economically marginalized people who use illicit drugs (PWUD). However, past literature paradoxically identifies unintended increases in drug-related harm coinciding with synchronized payments that may magnify signals for drug use. The scope of such harm has not been fully characterized among non-institutionalized populations. This study examined socio-demographic, health and drug use-related correlates of payment-coincident drug-related harm. This observational study uses data from prospective community-based longitudinal cohorts of PWUD between December 2013 and May 2018. Vancouver, British Columbia, Canada. A total of 1604 PWUD receiving monthly income assistance. Our sample included 586 (36.5%) women, 861 (53.7%) non-white participants and 685 (42.7%) people living with HIV. The primary outcome was a self-reported composite measure of drug-related harm in the past 6months coinciding with income assistance, including higher-frequency substance use, non-fatal overdose and service barriers or interruptions. Subanalyses disaggregated this outcome. Payment-coincident drug-related harm was reported among 77.7% of participants during the study period. In multivariable models, key correlates positively and significantly associated with payment-coincident harm included: street-based income generation [adjusted odds ratio (aOR)=1.48, 95% confidence interval (CI)=1.26-1.74, P<0.001], sex work (aOR=1.66, 95% CI=1.35-2.04, P<0.001), illegal income generation (aOR=1.57, 95% CI=1.35-1.83 P<0.001), homelessness (aOR=1.34, 95% CI=1.13-1.58, P<0.001), exposure to violence (aOR=1.31, 95% CI=1.03-1.66, P=0.032), daily crack cocaine use (aOR=1.99, 95% CI=1.59-2.50, P<0.001), heavy alcohol use (aOR=1.64, 95% CI=1.37-1.97, P<0.001) and injection drug use (aOR=2.55, 95% CI=2.01-3.23, P<0.001). In subanalyses, specific harms were more likely among individuals reporting social, structural and health vulnerabilities. In Vancouver, Canada, people who use illicit drugs who receive income assistance report high prevalence of payment-coincident drug-related harm, particularly people experiencing socioeconomic and structural marginalization or engaging in high-intensity drug use.

Moving into an urban drug scene among people who use drugs in Vancouver, Canada: Latent class growth analysis.

BackgroundUrban drug scenes are characterized by high prevalence of illicit drug dealing and use, violence and poverty, much of which is driven by the criminalization of people who use illicit drugs (PWUD) and the associated stigma. Despite significant public health needs, little is understood about patterns of moving into urban drug scenes among PWUD. Therefore, we sought to identify trajectories of residential mobility (hereafter ‘mobility’) among PWUD into the Downtown Eastside (DTES), an urban neighbourhood with an open drug scene in Vancouver, Canada, as well as characterize distinct trajectory groups among PWUD.MethodsData were derived from three prospective cohort studies of community-recruited PWUD in Vancouver between 2005 and 2016. We used latent class growth analysis (LCGA) to identify distinct patterns of moving into the DTES among participants residing outside of DTES at baseline. Multivariable multinomial logistic regression was used to determine baseline factors associated with each trajectory group.ResultsIn total, 906 eligible participants (30.9% females) provided 9,317 observations. The LCGA assigned four trajectories: consistently living outside of DTES (52.8%); early move into DTES (11.9%); gradual move into DTES (19.5%); and move in then out (15.8%). Younger PWUD, those of Indigenous ancestry, those who were homeless or living in a single-room occupancy hotel (SRO), and those injecting drugs daily were more likely to move in then out of DTES (all p<0.05). Living in an SRO, daily injection drug use, and recent incarceration were also positively associated with early mobility (all p<0.05).ConclusionsNearly half of the participants moved into the DTES. Younger PWUD and Indigenous peoples appeared to have particularly high mobility, as did those with markers of social-structural vulnerability and high intensity drug use. These findings indicate a need to tailor existing social and health services within the DTES and expand affordable housing options outside the DTES.

Substance use patterns and HIV-1 RNA viral load rebound among HIV-positive illicit drug users in a Canadian setting.

Active illicit drug use can present a barrier to the medical management of HIV infection by complicating adherence to antiretroviral therapy (ART). Plasma HIV-1 RNA viral load (VL) rebound, defined as a period of detectable HIV VL following ART and VL suppression, can lead to the generation of viral resistance and potential treatment failure. We sought to investigate the contribution of substance use patterns on rates of VL rebound. We used data from the ACCESS study, a long-running community-recruited prospective cohort of HIV-positive people who use illicit drugs in Vancouver, Canada, a setting of universal no-cost HIV treatment. We analysed time to VL rebound (that is, two consecutive observations ≥1,000 copies/ml) after ART initiation and sustained viral suppression (that is, two consecutive observations <50 copies/ml) using extended Cox regression models with a recurrent events framework. Between May 1996 and November 2013, 564 ART-exposed participants achieved at least one instance of VL suppression and contributed 1,893.8 person-years of observation. Over follow-up, 198 (35.1%) participants experienced ≥ one instance of VL rebound. In adjusted analyses, VL rebound was associated with younger age (adjusted hazard ratio [AHR] =0.97, 95% CI: 0.95, 0.98), heroin injection (≥ daily versus < daily, AHR =1.52, 95% CI: 1.01, 2.30), crack use (≥ daily versus < daily, AHR = 1.73, 95% CI: 1.08, 1.92) and heavy alcohol use (≥ four versus < four drinks/day, AHR =1.97, 95% CI: 1.17, 3.31). The present study suggests that in addition to heavy alcohol use, high-intensity illicit drug use, particularly ≥ daily heroin injection and ≥ daily crack smoking are risk factors for VL rebound. In addition to the impact of high-intensity drug use on health-care engagement and ART adherence, some evidence exists on the direct impact of psychoactive substances on ART metabolism and the natural progression of HIV disease. At-risk individuals should be provided additional supports to preserve virological control and maintain the benefits of ART.

Unsafe sexual behaviour associated with hazardous alcohol use among street-involved youth

ABSTRACTWhile risky sexual behaviours related to illicit drug use among street youth have been explored, the impacts of alcohol use have received less attention. This longitudinal study examined hazardous alcohol use among a population of street-involved youth, with particular attention to sexual and drug-related risk behaviours. Data were derived from the At-Risk Youth Study, a prospective cohort of street-involved youth in Vancouver, Canada. The outcome of interest was hazardous alcohol use defined by the US National Institute on Alcohol Abuse and Alcoholism. We used generalized estimating equations (GEEs) analyses to identify factors associated with hazardous alcohol use. Between 2005 and 2014, 1149 drug-using youth were recruited and 629 (55%) reported hazardous alcohol use in the previous 6 months during study follow-up. In multivariable GEE analyses, unprotected sex (adjusted odds ratio [AOR] = 1.28, 95% confidence interval [95% CI] = 1.12–1.46) and homelessness (AOR = 1.35, 95% CI = 1.19–1.54) were independently associated with hazardous alcohol use (all p < .001). Older age (AOR = 0.95, 95% CI = 0.92–0.99), Caucasian ethnicity (AOR = 0.74, 95% CI = 0.61–0.90), daily heroin use (AOR = 0.53, 95% CI = 0.42–0.67), daily crack cocaine smoking (AOR = 0.73, 95% CI = 0.59–0.91), and daily crystal methamphetamine use (AOR = 0.52, 95% CI = 0.42–0.64) were negatively associated with hazardous alcohol use (all p < .05). In sub-analysis, consistent dose–response patterns were observed between levels of alcohol use and unprotected sex, homelessness, and daily heroin injection. In sum, hazardous alcohol use was positively associated with unsafe sexual behaviour and negatively associated with high-intensity drug use. Interventions to address hazardous alcohol use should be central to HIV prevention efforts for street-involved youth.

High-Intensity Drug Use and Health Service Access Among Street-Involved Youth in a Canadian Setting

Background/Objectives: Addiction severity has been associated with numerous social- and health-related harms. This study sought to examine the prevalence and correlates of high-intensity drug use among street-involved youth in a Canadian setting with a focus on high-risk drug use practices and health service access.Methods: Data were derived from the At-Risk Youth Study, a Vancouver-based prospective cohort of street-involved youth aged 14–26. We used generalized estimating equations to examine variables associated with high-intensity drug use, defined as daily use of crack cocaine, cocaine, heroin, or crystal methamphetamine. Results: From September 2005 to November 2012, of 1017 youth included in the analyses, 529 (52%) reported high-intensity drug use as defined above at least once during the study period. In a multivariate analysis, older age (Adjusted Odds Ratio [AOR] = 1.47); residing in the Downtown Eastside of Vancouver (AOR = 1.46); homelessness (AOR = 1.30); recent incarceration (AOR = 1.25); inability to access addiction treatment (AOR = 1.42); and crack pipe sharing and/or used syringe injecting (AOR = 2.64), were all positively and independently associated with high-intensity drug use (p < 0.05). The most common barrier to accessing addiction treatment reported by these youth was long waiting lists. Conclusions: High-intensity drug use among street-involved youth was prevalent and associated with structural and geographical disadvantages in addition to high-risk drug administration practices. Youth reporting more frequent drug use also reported barriers to accessing addiction treatment, highlighting the need to expand addiction services tailored to youth at greatest risk of harm from illicit drug use and street-involvement.

Socioeconomic marginalization and plasma HIV-1 RNA nondetectability among individuals who use illicit drugs in a Canadian setting.

Given that people who use illicit drugs (PWUD) often engage in prohibited income generation to support their basic needs, we sought to examine the role of these activities in shaping antiretroviral therapy (ART) adherence and plasma HIV RNA-1 viral load suppression among HIV-infected PWUD. Longitudinal analyses among HIV-positive, ART-exposed PWUD in the AIDS Care Cohort to evaluate Exposure to Survival Services prospective cohort study (2005-2013). Generalized linear mixed-effects and mediation analyses examined the relationship between prohibited income generation (e.g., sex work, drug dealing, theft, street-based income) and virologic suppression (plasma viral load ≤50 copies/ml plasma) adjusting for adherence and potential confounders. Among 687 HIV-infected PWUD, 391 (56.9%) individuals reported prohibited income generation activity during the study period. In multivariate analyses, prohibited income generation remained independently and negatively associated with virologic suppression (adjusted odds ratio: 0.68, 95% confidence interval: 0.52-0.88) following adjustment for hypothesized confounders, including high-intensity drug use, ART adherence and homelessness. Although partially mediated by ART adherence, the relationship between prohibited income generation and virologic suppression was maintained in mediation analyses (Sobel statistic = -1.95, P = 0.05). Involvement in prohibited income generation decreases the likelihood of virologic suppression directly and indirectly through its negative association with ART adherence. These findings suggest that linkages between socioeconomic marginalization, the criminalization of illicit drug use, and insufficient employment opportunities may produce barriers to access and retention in care. Programmatic and policy interventions that decrease socioeconomic vulnerability may therefore reduce HIV-related morbidity, mortality, and onward transmission.

High prevalence of syringe lending among HIV-positive people who inject drugs in Bangkok, Thailand.

BackgroundSyringe sharing continues to be a major driver of the HIV pandemic. In light of efforts to enhance access to sterile syringes and promote secondary prevention among HIV-positive individuals, we sought to identify the prevalence and correlates of used syringe lending among self-reported HIV-positive people who inject drugs (PWID) in Bangkok, Thailand.FindingsWe used bivariable statistics to examine factors associated with self-reported syringe lending among self-reported HIV-positive PWID participating in the Mitsampan Community Research Project, a serial cross-sectional study of PWID in Bangkok, between June 2009 and October 2011. In total, 127 individuals were eligible for this analysis, including 25 (19.7 %) women. Twenty-one (16.5 %) participants reported syringe lending in the prior 6 months. Factors significantly associated with syringe lending included daily methamphetamine injection (odds ratio (OR) = 10.2, 95 % CI, 2.1–53.6), daily midazolam injection (OR = 3.1, 95 % CI, 1.1–8.7), use of drugs in combination (OR = 4.5, 95 % CI, 1.0–41.6), injecting with others on a frequent basis (OR = 4.25, 95 % CI, 1.3–18.3), and not receiving antiretroviral therapy (OR = 2.9, 95 % CI, 1.1–7.9).ConclusionsA high prevalence of syringe lending was observed among self-reported HIV-positive PWID in Bangkok, which was associated with high intensity drug use, polysubstance use, and frequently injecting with others. It is particularly concerning that individuals who lent syringes were more likely to be untreated for HIV disease given the known benefits of antiretroviral provision on the prevention of HIV transmission. These findings underscore the need to expand access to sterile syringes and HIV treatment among HIV-positive PWID in Thailand.

Utilizing mHealth methods to identify patterns of high risk illicit drug use

IntroductionWe assessed patterns of illicit drug use using mobile health (mHealth) methods and subsequent health care indicators among drug users in Baltimore, MD. MethodsParticipants of the EXposure Assessment in Current Time (EXACT) study were provided a mobile device for assessment of their daily drug use (heroin, cocaine or both), mood and social context for 30 days from November 2008 through May 2013. Real-time, self-reported drug use events were summed for individuals by day. Drug use risk was assessed through growth mixture modeling. Latent class regression examined the association of mHealth-defined risk groups with indicators of healthcare access and utilization. Results109 participants were a median of 48.5 years old, 90% African American, 52% male and 59% HIV-infected. Growth mixture modeling identified three distinct classes: low intensity drug use (25%), moderate intensity drug use (65%) and high intensity drug use (10%). Compared to low intensity drug users, high intensity users were younger, injected greater than once per day, and shared needles. At the subsequent study visit, high intensity drug users were nine times less likely to be medically insured (adjusted OR: 0.10, 95%CI: 0.01–0.88) and at greater risk for failing to attend any outpatient appointments (aOR: 0.13, 95%CI: 0.02–0.85) relative to low intensity drug users. ConclusionsReal-time assessment of drug use and novel methods of describing sub-classes of drug users uncovered individuals with higher-risk behavior who were poorly utilizing healthcare services. mHealth holds promise for identifying individuals engaging in high-risk behaviors and delivering real-time interventions to improve care outcomes.

Barriers to health and social services for street-involved youth in a Canadian setting.

Although street-involved youth contend with many health and social problems, the extent to which vulnerable youth engage with supportive services has not been well described. This study sought to examine the prevalence and correlates associated with having difficulty accessing health and social services among a prospective cohort of street-involved youth in Vancouver, Canada. Among 1019 street-involved youth, 650 (64 per cent) reported having difficulty accessing services during the study period. In a multivariate analysis, youth who reported having difficulty accessing services were significantly more likely to be socially and economically vulnerable. Specifically, they were more likely to report severe housing instability, high-intensity drug use, recent interactions with law enforcement, drug dealing, and histories of violence and physical abuse. Study findings point to opportunities to improve access to services among vulnerable youth through removal of blanket age restrictions for youth services, establishing youth-centric social housing, and supporting peer-driven, low-threshold services.

Crack pipe sharing among street-involved youth in a Canadian setting.

Crack pipe sharing is a risky practice that has been associated with the transmission of hepatitis C and other harms. While previous research has exclusively focused on this phenomenon among adults, this study examines crack pipe sharing among street-involved youth. From May 2006 to May 2012, data were collected from the At-Risk Youth Study, a cohort of street-involved youth aged 14-26 in Vancouver, Canada. Survey data from active crack smokers were analysed using generalised estimating equations logistic regression. Over the study period, 567 youth reported smoking crack cocaine and contributed 1288 observations, among which 961 (75%) included a report of crack pipe sharing. In multivariate analysis, factors that were associated with crack pipe sharing included difficulty accessing crack pipes [adjusted odds ratio (AOR) = 1.58, 95% confidence interval (CI) 1.13-2.20]; homelessness (AOR = 1.87, 95% CI 1.43-2.44); regular employment (AOR = 1.53, 95% CI 1.15-2.04); daily non-injection crystal methamphetamine use (AOR = 2.04, 95% CI 1.11-3.75); daily crack smoking (AOR = 1.37, 95% CI 1.01-1.85); encounters with the police (AOR = 1.42, 95% CI 1.01-1.99); and reporting unprotected sex (AOR = 1.95, 95% CI 1.47-2.58). The prevalence of crack pipe sharing was high among our sample and independently associated with structural factors including difficulty accessing crack pipes and homelessness. Crack pipe sharing was also associated with high-intensity drug use and a number of other markers of risk and vulnerability. Collectively, these findings highlight opportunities for health services to better engage with this vulnerable group and reduce this risky behaviour.

HIV Test Avoidance Among People Who Inject Drugs in Thailand

Case identification is a key component of HIV prevention efforts; yet rates of HIV testing remain low in some settings. We explored factors associated with HIV test avoidance among people who inject drugs (IDU) in Thailand. Between July and October 2011, 350 Thai IDU participated in the study. In bivariate analyses, male gender, high intensity drug use, syringe sharing, increased police presence, and being refused healthcare services were positively associated with HIV test avoidance, while ever receiving a hepatitis C test was negatively associated. Our findings highlight the need for interventions to reduce stigma in this setting.