High-intensity cannabis use and HIV clinical outcomes among HIV-positive people who use illicit drugs in Vancouver,Canada

BackgroundReforms to the legal status of medical and non-medical cannabis are underway in many jurisdictions, including Canada, as are renewed efforts to scale-up HIV treatment-as-prevention (TasP) initiatives. It has been suggested that high-intensity cannabis use may be associated with sub-optimal HIV treatment outcomes. Thus, using data from a setting with a community-wide treatment-as-prevention (TasP) initiative coinciding with increasing access to medical cannabis, we sought to investigate the possible impact of high-intensity cannabis use on HIV clinical outcomes.MethodsData was derived from the ACCESS study, a prospective cohort of HIV-positive people who use illicit drugs (PWUD) in Vancouver, Canada. Cohort data was confidentially linked to comprehensive clinical profiles, including records of all antiretroviral therapy (ART) dispensations and longitudinal plasma HIV-1 RNA viral load (VL) monitoring. We used generalized estimating equations (GEEs) to estimate the longitudinal bivariable and multivariable relationships between at least daily cannabis use and two key clinical outcomes: overall engagement in ART care, and achieving a non-detectable VL among ART-exposed participants.ResultsBetween December 2005 and June 2015, 874 HIV-positive PWUD (304 [35%] non-male) were included in this study. In total, 788 (90%) were engaged in HIV care at least once over the study period, of whom 670 (85%) achieved non-detectable VL at least once. In multivariable analyses, ≥ daily cannabis use did not predict lower odds of ART care (Adjusted Odds Ratio [AOR]: 1.02, 95% confidence interval [CI]: 0.77–1.36) or VL non-detectability among ART-exposed (AOR: 0.96, 95% CI: 0.75–1.21). Upon testing for potential interactions, ≥ daily cannabis use was found to be negatively associated with ART engagement during periods of binge alcohol use (p < 0.05).ConclusionWith the exception of frequent cannabis use during periods of binge alcohol use, our results showed no statistically significant impact of daily cannabis use on the likelihood of ART care or VL non-detectability among ART-exposed HIV-positive PWUD. These findings are reassuring in light of the impending legalization of cannabis in Canada and ongoing efforts to expand TasP initiatives.     

Hepatitis C cascade of care among people who inject drugs in Vancouver,Canada

Background: People who inject drugs (PWID) have high rates of hepatitis C virus (HCV) infection. Little is known about the rates of diagnosis and treatment for HCV among PWID. Therefore, this study aims to characterize the cascade of care in Vancouver, Canada, to improve HCV treatment access and delivery for PWID. Methods: Data were derived from 3 prospective cohort studies of PWID in Vancouver, Canada, between December 2005 and May 2015. The progression of participants was identified through 5 steps in the cascade of care: (1) chronic HCV; (2) linkage to HCV care; (3) liver disease assessment; (4) initiation of treatment; and (5) completion of treatment. Predictors of undergoing liver disease assessment for HCV treatment were identified using a multivariable extended Cox regression model. Results: Among 1571 participants with chronic HCV, 1359 (86.5%) had ever been linked to care, 1257 (80.0%) had undergone liver disease assessment, 163 (10.4%) had ever started HCV treatment, and 71 (4.5%) had ever completed treatment. In multivariable analyses, human immunodeficiency virus (HIV) seropositivity, use of methadone maintenance therapy, and hospitalization in the past 6?months were independently and positively associated with undergoing liver disease assessment (all P?<?.001), whereas daily heroin injection was independently and negatively associated with undergoing liver disease assessment (P?<?.001). Conclusions: Among this cohort of PWID, few had been started on or completed treatment for HCV. These findings highlight the need to improve the prescribing of HCV treatment among PWID with active substance use.     

Residential eviction and exposure to violence among people who inject drugs in Vancouver,Canada

BackgroundPeople who inject drugs (PWID) experience markedly elevated rates of physical and sexual violence, as well as housing instability. While previous studies have demonstrated an association between homelessness and increased exposure to violence among PWID, the relationship between residential eviction and violence is unknown. We therefore sought to examine the association between residential eviction and experiencing violence among PWID in Vancouver, Canada.MethodsData were derived from two open prospective cohort studies of PWID: the Vancouver Injection Drug Users Study (VIDUS) and the AIDS Care Cohort to evaluate Exposure to Survival Services (ACCESS). We used generalized estimating equations (GEE) to estimate the relationship between residential eviction and experiencing violence among male and female PWID, respectively.ResultsBetween June 2007 and May 2014, 1689 participants were eligible for the analysis, contributing a median of 5.5 years of follow-up. Of these, 567 (33.6%) were female. In total, 259 (45.7%) of females and 566 (50.4%) of males experienced at least one incident of violence over the study period. In multivariable GEE models, residential eviction was independently associated with greater odds of experiencing violence among both females (Adjusted Odds Ratio [AOR] = 2.09; 95% confidence interval [CI]: 1.39–3.13) and males (AOR = 1.95; 95% CI = 1.49–2.55), after adjustment for potential confounders.ConclusionResidential eviction was independently associated with an increased likelihood of experiencing violence among both male and female PWID. These findings point to the need for evidence-based social-structural interventions to mitigate housing instability and violence among PWID in this setting.     

Frequent emergency department presentations among people who inject drugs: A record linkage study

BackgroundPeople who inject drugs (PWID) have been described as frequent users of health services such as emergency departments (EDs), however few studies have described demographic factors, patterns of substance use and previous health service use associated with frequent use of EDs in this population.MethodsUsing a combination of self-reported data from a cohort of PWID and administrative ED data obtained through record linkage, we identified longitudinal factors associated with the use of ED services. Bivariate and multivariate analyses were conducted using negative binomial regression to identify exposures associated with both cumulative ED presentations, and logistic regression to identify exposures of frequent ED presentations (defined as three or more annual presentations).ResultsAmong 612 PWID, over half (58%) presented to EDs at least once and over a third (36%) presented frequently between January 2008 and June 2013. Frequent and cumulative ED presentations were associated with reporting the main drug of choice as cannabis (AOR:1.42, 95%CI:1.07–1.89 and AIRR:2.96, 95%CI:1.44–6.07 respectively) or methamphetamine (AOR:1.62, 95%CI:1.17–2.2 and AIRR:2.42, 95%CI:1.08–5.46 respectively) compared to heroin, and past month use of mental health (AOR:1.42, 95%CI:1.08–1.85 and AIRR:3.32, 95%CI:1.69–6.53 respectively) and outpatient services (AOR:1.47, 95%CI: 1.00–2.16 and AIRR:0.95, 95%CI 1.52–10.28 respectively).ConclusionPWID who are frequent users of EDs are likely to have complex health and substance use-related needs. EDs should actively refer people who present with cannabis and methamphetamine dependence to harm reduction services. Harm reduction services should ensure people referred from EDs are screened for co-occurring mental health conditions and receive adequate support.     

Childhood bullying behaviors at age eight and substance use at age 18 among males. A nationwide prospective study

Childhood bullying behaviors (bullying and victimization) were studied as risk factors for substance use among Finnish males. The study design was a nationwide prospective general population study, where information was collected in 1989 and 1999. Bullying behaviors and childhood psychopathology at age eight were collected from teachers, parents and boys themselves. At age 18, self-reports of frequent drunkenness (once a week or more often), daily heavy smoking (10 cigarettes or more per day), and illicit drug use during the past six months were obtained from 78% of the boys attending the study at age eight (n=2946). Being frequently victimized at age eight predicted daily heavy smoking, and this was evident even after adjusting for childhood family background, psychopathology at age eight and at age 18, and other forms of substance use. In multivariate analysis, bullying others frequently predicted illicit drug use, while being a victim of bullying associated with a lower occurrence of illicit drug use. Bullying behaviors had no association with frequent drunkenness independent of other factors. Accordingly, being a victim of bullying predisposes in particular to subsequent smoking. Bullying others in childhood can be regarded as an early indicator to illicit drug use later in life. The screening and intervention possibilities in order to recognize the risk group for later health compromising behaviors are emphasized.     

Awareness and understanding of HIV non-disclosure case law among people living with HIV who use illicit drugs in a Canadian setting

BackgroundIn 2012, the Supreme Court of Canada (SCC) ruled that people living with HIV (PLWH) could face criminal charges if they did not disclose their serostatus before sex posing a “realistic possibility” of HIV transmission. Condom-protected vaginal sex with a low (i.e., <1500 copies/mL) HIV viral load (VL) incurs no duty to disclose. Awareness and understanding of this ruling remain uncharacterized, particularly among marginalized PLWH.MethodsWe used data from ACCESS, a community-recruited cohort of PLWH who use illicit drugs in Vancouver. The primary outcome was self-reported awareness of the 2012 SCC ruling, drawn from cross-sectional survey data. Participants aware of the ruling were asked how similar their understanding was to a provided definition. Sources of information from which participants learned about the ruling were determined. Multivariable logistic regression identified factors independently associated with ruling awareness.ResultsAmong 249 participants (39% female), median age was 50 (IQR: 44–55) and 80% had a suppressed HIV VL (<50 copies/mL). A minority (112, 45%) of participants reported ruling awareness, and 44 (18%) had a complete understanding of the legal obligation to disclose. Among those aware (n = 112), newspapers/media (46%) was the most frequent source from which participants learned about the ruling, with 51% of participants reporting that no healthcare providers had talked to them about the ruling. Ruling awareness was negatively associated with VL suppression (AOR:0.51, 95% CI:0.27,0.97) and positively associated with recent condomless sex vs. no sex (AOR:2.00, 95% CI:1.03,3.92).ConclusionMost participants were not aware of the 2012 SCC ruling, which may place them at risk of prosecution. Discussions about disclosure and the law were lacking in healthcare settings. Advancing education about HIV disclosure and the law is a key priority. The role of healthcare providers in delivering information and support to PLWH in this legal climate should be further explored.     

Proximal to distal correlates of the patterns of illicit drug use among night school students in Taiwan

This epidemiological study aimed to investigate illicit drug use by vocational high school night-class students in Taiwan to identify hypothesized proximal and distal factors associated with drug use patterns. Between September 2010 and January 2011, a randomized sample was drawn from 33 vocational high school night classes, enrolling 1079 students already employed outside campus. Subjects completed a validated self-reported questionnaire measuring proximal factors (biological, psychological, and behavioral) and distal factors (living with parents, parents' or siblings' use of legal substances, supervision by primary guardian, and perceived peer influence on drug use). Age, greater sensation-seeking behavior and legal substances use (i.e., tobacco and betel nuts) increased odds of being identified as experimental or regular users versus non-drug users. Higher rates of rule-breaking behavior were associated with increased odds of being identified as experimental users versus non-drug users. Among distal factors, only perceived peer influence on drug use was significantly associated with experimental and regular drug use. Proximal and distal factors were associated with drug use patterns among vocational high school night-class students. Influence factors identified may help vocational high school officials design effective illicit drug intervention programs for students with different drug use patterns.     

Recessions and the participation of youth in the selling and use of illicit drugs

Background

There has been limited research on how recessions (or more generally, the strength of the economy) affect drug use and the related outcome of drug selling. This is especially important, given the current economic crisis. This paper aims to use a conceptual framework, previous research, and new research to predict how the current economic crisis may be affecting youth drug selling and drug use.

Methods

A conceptual framework to understand how a recession could affect youth drug selling and drug use is presented, along with a review of the literature on empirical investigations on how the strength of the economy affects these behaviours among teenagers. In addition, new analyses for young adults are presented.

Results

The conceptual framework postulates that a recession would have direct positive effects on the prevalence of youth drug selling but ambiguous direct effects on youth drug use. The conceptual framework also postulates that drug selling and drug use are inter-connected at the individual level and the aggregate level. Thus, any effect of a recession on one would likely affect the other in the same direction. The limited empirical evidence indicates that both drug selling and drug use among youth are higher when the economy is weaker.

Conclusions

The current economic crisis will likely increase both youth drug selling and drug use relative to what they would have otherwise been.     

Child and adolescent externalizing behavior and cannabis use disorders in early adulthood: an Australian prospective birth cohort study

This study examined the association between age of onset and persistence of externalizing behavior and young adults' cannabis use disorders (CUDs). Data were from a 21 year follow-up of a birth cohort study in Brisbane, Australia. The present cohort consisted of 2225 young adults who had data available about CUDs at 21 years and externalizing behavior at 5 and 14 years. Young adults' CUDs were assessed using the CIDI-Auto. Child and adolescent externalizing behavior were assessed at the 5- and 14-year phases of the study. After controlling for confounding variables, children who had externalizing behavior at both 5 and 14 years (child-onset-persistent) (COP) had a substantial increase in risk of CUD at age 21 years (Odds ratio (OR)=2.5; 95% CI: 1.5, 4.2). This association was similar for those who had 'adolescent onset' (AO) externalizing behavior. However, there was no association between 'childhood limited' (CL) externalizing behavior and CUD. Externalizing behavior in adolescence is a strong predictor of subsequent CUD. Smoking and drinking at 14 years partially mediated the link between externalizing behavior and CUD.     

Predicting the transition from frequent cannabis use to cannabis dependence: A three-year prospective study

Background

Frequent cannabis users are at high risk of dependence, still most (near) daily users are not dependent. It is unknown why some frequent users develop dependence, whereas others do not. This study aims to identify predictors of first-incidence DSM-IV cannabis dependence in frequent cannabis users.

Methods

A prospective cohort of frequent cannabis users (aged 18–30, n = 600) with baseline and two follow-up assessments (18 and 36 months) was used. Only participants without lifetime diagnosis of DSM-IV cannabis dependence at baseline (n = 269) were selected. Incidence of DSM-IV cannabis dependence was established using the Composite International Diagnostic Interview version 3.0. Variables assessed as potential predictors of the development of cannabis dependence included sociodemographic factors, cannabis use variables (e.g., motives, consumption habits, cannabis exposure), vulnerability factors (e.g., childhood adversity, family history of mental disorders or substance use problems, personality, mental disorders), and stress factors (e.g., life events, social support).

Results

Three-year cumulative incidence of cannabis dependence was 37.2% (95% CI = 30.7–43.8%). Independent predictors of the first incidence of cannabis dependence included: living alone, coping motives for cannabis use, number and type of recent negative life events (major financial problems), and number and type of cannabis use disorder symptoms (impaired control over use). Cannabis exposure variables and stable vulnerability factors did not independently predict first incidence of cannabis dependence.

Conclusions

In a high risk population of young adult frequent cannabis users, current problems are more important predictors of first incidence cannabis dependence than the level and type of cannabis exposure and stable vulnerability factors.     

Police violence among people who inject drugs in Baltimore,Maryland

Background: Police violence is a deleterious public health and criminal justice issue that disproportionately affects people who inject drugs (PWID). Studies documenting the prevalence and correlates of physical police violence in this population are rare. The aim of this study was to examine the correlates of past year physical police violence among an urban sample of PWID.Methods: PWID participating in the 2015 wave of the National HIV Behavioral Surveillance (NHBS) system in Baltimore City, Maryland, completed a socio-behavioral survey. Multivariable logistic regression was used to detect the socio-demographic, place-based, law-enforcement and health behavior correlates of exposure to police violence as well as knowledge of violence directed towards other PWID.Results: Enrolled PWID (N = 570) were mostly male (72%), non-Hispanic Black (77%) and daily heroin injectors (86%). Seven percent had experienced past year physical police violence (Respondent-Driven Sampling [RDS] weighted estimate: 4%), and a quarter (24%) knew someone who had experienced physical police violence in the past year (RDS-weighted estimate: 17%). Male gender, homelessness, arrest, drug paraphernalia confiscation, and receptive syringe sharing were independently associated with police violence. Knowing someone who had experienced police violence was independently correlated with selling drugs, arrest, and attending a syringe services program.Conclusion: Population differences in the extent of police violence exposure indicate that experiences of police violence are not uniform among PWID. Violent encounters with police were associated with disruptions in harm reduction strategies that can prevent HIV and HCV transmission. This study adds to the small body of public health literature on police violence and highlights the importance of monitoring and addressing this critical issue.     

Tobacco, alcohol, cannabis and other illegal drug use among young adults: the socioeconomic context

Background

Low socioeconomic position predicts risk of substance abuse, yet few studies tested the role of preexisting familial and individual characteristics.

Methods

Data come from the TEMPO (Trajectoires Epidémiologiques en Population) study (community sample in France, 1991–2009, n = 1103, 22–35 years in 2009) set up among offspring of participants of an epidemiological study (GAZEL). Past 12-month substance use was assessed in 2009 by self-completed mail survey: regular tobacco smoking, alcohol abuse (AUDIT), cannabis use, problematic cannabis use (CAST), other illegal drug use. Socioeconomic position was defined by educational attainment, occupational grade, employment stability and unemployment. Covariates included demographics (age, sex, relationship status, parenthood), family background (parental income, parental tobacco smoking, parental alcohol use), and juvenile characteristics (psychological problems, academic difficulties) measured longitudinally.

Results

35.8% of study participants were regular smokers, 14.3% abused alcohol, 22.6% used cannabis (6.3% had problematic cannabis use) and 4.1% used other illegal drugs. Except for alcohol abuse, substance use rates were systematically higher in individuals with low, rather than intermediate/high, socioeconomic position (age and sex-adjusted ORs from 1.75 for cannabis use to 2.11 for tobacco smoking and 2.44 for problematic cannabis use). In multivariate analyses these socioeconomic disparities were decreased, but remained statistically significant (except for illegal drugs other than cannabis).

Conclusions

Tobacco smoking, alcohol, cannabis and polysubstance use are common behaviors among young adults, particularly those experiencing socioeconomic disadvantage. Interventions aiming to decrease substance abuse and reduce socioeconomic inequalities in this area should be implemented early in life.     

Interest in low-threshold employment among people who inject illicit drugs: implications for street disorder

Background

Income generation opportunities available to people who use illicit drugs have been associated with street disorder. Among a cohort of injection drug users (IDU) we sought to examine street-based income generation practices and willingness to forgo these sources of income if other low-threshold work opportunities were made available.

Methods

Data were derived from a prospective community recruited cohort of IDU. We assessed the prevalence of engaging in disorderly street-based income generation activities, including sex work, drug dealing, panhandling, and recycling/salvaging/vending. Using multivariate logistic regressions based on Akaike information criterion and the best subset selection procedure, we identified factors associated with disorderly income generation activities, and assessed willingness to forgo these sources of income during the period of November 2008 to July 2009.

Results

Among our sample of 874 IDU, 418 (48%) reported engaging in a disorderly income generation activity in the previous six months. In multivariate analyses, engaging in disorderly income generation activities was independently associated with high intensity stimulant use, as well as binge drug use, having encounters with police, being a victim of violence, sharing used syringes, and injecting in public areas. Among those engaged in disorderly income generation, 198 (47%) reported a willingness to forgo these income sources if given opportunities for low-threshold employment, with sex workers being most willing to engage in alternative employment.

Conclusion

Engagement in disorderly street-based income generation activities was associated with high intensity stimulant drug use and various markers of risk. We found that a high proportion of illicit drug users were willing to cease engagement in these activities if they had options for causal low-threshold employment. These findings indicate that there is a high demand for low-threshold employment that may offer important opportunities to reduce drug-related street disorder and associated harms.