Prevalence and Correlates of Heavy Alcohol use among People Living with HIV who use Unregulated Drugs in Vancouver, Canada.

Among people living with HIV (PLWH), heavy alcohol use is associated with many negative health consequences. However, the impacts of heavy alcohol use are not well described for PLWH who use drugs. Thus, we investigated the prevalence and correlates of heavy alcohol use among a cohort of people who use drugs (PWUD) living with HIV in Vancouver, Canada. We accessed data from an ongoing community-recruited prospective cohort of PLWH who use drugs with linked comprehensive HIV clinical monitoring data. We used generalized linear mixed-effects modeling to identify factors longitudinally associated with periods of heavy alcohol use between December 2005 and December 2019. Of the 896 participants included, 291 (32.5%) reported at least one period with heavy alcohol use. Periods of recent incarceration (Adjusted Odds Ratio [AOR] = 1.48, 95% Confidence Interval [CI]: 1.01-2.17), encounters with police (AOR = 1.87, 95% CI: 1.37-2.56), and older age (AOR = 1.05, 95% CI: 1.02-1.07) were positively associated with heavy alcohol use. Engagement in drug or alcohol treatment (AOR = 0.54, 95% CI: 0.42-0.70) and male gender (AOR = 0.46; 95% CI: 0.27-0.78) were negatively associated with heavy alcohol use. We observed that heavy alcohol use was clearly linked to involvement with the criminal justice system. These findings, together with the protective effects of substance use treatment, suggest the need to expand access for drug and alcohol treatment programs overall, and in particular through the criminal justice system to reduce alcohol-related harms among PLWH who use drugs.

Denial of prescription pain medication among people who use drugs in Vancouver, Canada.

BACKGROUND: People who use drugs experience pain at two to three times the rate of the general population and yet continue to face substantial barriers to accessing appropriate and adequate treatment for pain. In light of the overdose crisis and revised opioid prescribing guidelines, we sought to identify factors associated with being denied pain medication and longitudinally investigate denial rates among people who use drugs. METHODS: We used multivariable generalized estimating equations analyses to investigate factors associated with being denied pain medication among people who use drugs reporting pain in three prospective cohort studies in Vancouver, Canada. Analyses were restricted to study periods in which participants requested a prescription for pain from a healthcare provider. Descriptive statistics detail denial rates and actions taken by participants after being denied. RESULTS: Among 1168 participants who requested a prescription for pain between December 2012 and March 2020, the median age was 47 years and 63.0% were male. Among 4,179 six-month observation periods, 907 (21.7%) included a report of being denied requested pain medication. In multivariable analyses, age was negatively associated with prescription denial (adjusted odds ratio [AOR] = 0.98, 95% confidence interval [CI]:0.97-0.99), while self-managing pain (AOR = 2.48, 95%CI:2.04-3.00), experiencing a non-fatal overdose (AOR = 1.51, 95%CI:1.22-1.88), engagement in opioid agonist therapy (AOR = 1.32, 95%CI:1.09-1.61), and daily use of heroin or other unregulated opioids (AOR = 1.32, 95%CI:1.05-1.66) were positively associated with being denied. Common actions taken (n = 895) after denial were accessing the unregulated drug supply (53.5%), doing nothing (30.6%), and going to a different doctor/emergency room (6.1%). The period following the introduction of new prescribing guidelines was not associated with a change in denial rates. CONCLUSIONS: A substantial proportion of people who use drugs continue to be denied prescriptions for pain, with such denial associated with important substance use-related harms, including non-fatal overdose. Guidelines specific to the pharmaceutical management of pain among people who use drugs are needed.

Characterizing Use of Supervised Consumption Services among Street-involved Youth and Young Adults in the Context of an Overdose Crisis.

In response to an increase in overdose deaths, there was a rapid scale-up of supervised consumption services (SCS), including federally sanctioned SCS and low-barrier SCS known as overdose prevention sites (OPS), in Vancouver, Canada, beginning in December 2016. However, little is known about the use of such services among adolescents and young adults (AYA) in this context. We therefore sought to characterize factors associated with the use of federally sanctioned SCS and OPS among street-involved AYA who inject drugs in Vancouver during an overdose crisis. From December 2016 to March 2020, data were collected from a prospective cohort of street-involved AYA aged 14 to 26 at baseline. Using multivariable generalized estimating equation analyses, we identified factors associated with recent use of federally sanctioned SCS and OPS, respectively. Among 298 AYA who inject drugs, 172 (57.8%) and 149 (50.0%) reported using federally sanctioned SCS and OPS during the study period, respectively. In multivariable analyses, public injecting, negative police interactions, and residing or spending time ≥ weekly in the Downtown Eastside neighborhood were all positively associated with the use of federally sanctioned SCS and OPS, respectively. Additionally, ≥ daily unregulated opioid use and residential eviction were positively associated with federally sanctioned SCS use, while requiring help injecting was inversely associated. Self-identified female or non-binary gender was also positively associated with OPS use (all p < 0.05). Both federally sanctioned SCS and OPS successfully engaged AYA at heightened risk of adverse health outcomes. However, the lack of accommodation of AYA who require manual assistance with injecting at federally sanctioned SCS may be inhibiting service engagement.

COVID-19 vaccination among young people who use drugs in Vancouver, Canada.

OBJECTIVES: SARS-CoV-2 vaccines provide significant protection against severe illness and death from COVID-19, in addition to reducing community transmission. Emerging research has identified factors associated with vaccine uptake among adults who use drugs; however, less is known about youth and young adults who use drugs (YWUD). To address this gap, we sought to characterize factors associated with vaccine uptake and explore vaccine hesitancy among YWUD. METHODS: Data were derived from the At-Risk Youth Study, a prospective cohort of street-involved YWUD in Vancouver, Canada. Using multivariable logistic regression, we characterized factors associated with SARS-CoV-2 vaccine uptake between June and November 2021. Data on vaccine hesitancy were also collected. RESULTS: Among 301 participants enrolled in this study (median age: 29 [min and max: 20-40]), 151 (50.2%) self-reported receipt of at least one dose of a SARS-CoV-2 vaccine. In multivariable analysis, vaccine uptake was significantly associated with recent addiction treatment engagement (adjusted odds ratio [AOR] = 2.46, 95% confidence interval [CI]: 1.47-4.14) and receiving prescribed safer supply (e.g., opioids, stimulants) (AOR = 2.33, 95% CI: 1.03-5.62). Those who reported at least weekly crack use were significantly less likely to be vaccinated (AOR = 0.35, 95% CI: 0.12-0.92). The most reported reason for vaccine hesitancy was safety concerns, specifically regarding long-term side effects (27.4%). CONCLUSION: Vaccine uptake was significantly lower among YWUD than adults who use drugs in Vancouver and the general population in British Columbia, among whom 75% and 93% received at least one dose during the same period. Study findings suggest connecting YWUD to healthcare and novel harm reduction interventions may increase vaccine uptake. Responses to vaccine hesitancy questions revealed complex perspectives of vaccines that were aligned with sources of vaccine hesitancy among the general population. Broader strategies combatting misinformation and promoting evidence-based vaccine information could be tailored to address the unique needs and barriers experienced by YWUD.

Effect of modified income assistance payment schedules on substance use service access: Evidence from an experimental study.

BACKGROUND: Despite being critical to reducing the impacts of poverty internationally, synchronized monthly government income assistance payments are linked to intensified drug use and associated harms, including disrupted access to substance use-related services. This study evaluates whether alternative income assistance distribution schedules improve harm reduction (HR), pharmacotherapy and substance use service utilization. METHODS: This exploratory, parallel group, unblinded, randomized controlled trial analyzed data from adults (n = 192) in Vancouver, Canada receiving income assistance, and reporting active, regular illicit drug use. Participants were randomly assigned on a 1:2:2 basis for six income assistance payment cycles to: (1) existing government schedules (control); (2) a "staggered" single monthly payment; or (3) "split & staggered" twice-monthly payments. Generalized linear mixed models analyzed secondary outcomes of HR, pharmacotherapy and substance use service utilization as well as barriers accessing these services. RESULTS: Forty-five control, 71 staggered, and 76 split & staggered volunteers participated between 2015 and 2019. Multivariable modified per-protocol analyses demonstrate increased access to substance use services (Adjusted Odds Ratio [AOR] 1.64, 95% Confidence Interval [CI] 1.02-2.64) for split & staggered arm participants, and, conversely, increased barriers to HR for participants in the staggered (AOR 2.34, 95% CI 1.24-4.41) and split & staggered (AOR 2.16, 95% CI 1.08-4.35) arms. Results also showed decreased barriers to pharmacotherapy around government payments (AOR 0.23, 95% CI 0.06-0.90), pharmacotherapy around individual payments (AOR 0.12, 95% CI 0.02-0.58), and HR around individual payments (AOR 0.11, 95% CI 0.02-0.63) for staggered arm participants. CONCLUSION: Modifying payments schedules demonstrate improved access to overall substance use services, and reduced barriers to HR and pharmacotherapy around income assistance payments. However, increased overall barriers to HR access were also shown. These complex, predominantly beneficial findings support the exploration of offering alternative payment schedules to support service access.

The Association Between Self-Reported Anxiety and Retention in Opioid Agonist Therapy: Findings From a Canadian Pragmatic Trial.

BACKGROUND: Prescription-type opioid use disorder (POUD) is often accompanied by comorbid anxiety, yet the impact of anxiety on retention in opioid agonist therapy (OAT) is unclear. Therefore, this study investigated whether baseline anxiety severity affects retention in OAT and whether this effect differs by OAT type (methadone maintenance therapy (MMT) vs. buprenorphine/naloxone (BNX)). METHODS: This secondary analysis used data from a pan-Canadian randomized trial comparing flexible take-home dosing BNX and standard supervised MMT for 24 weeks. The study included 268 adults with POUD. Baseline anxiety was assessed using the Beck Anxiety Inventory (BAI), with BAI ≥ 16 indicating moderate-to-severe anxiety. The primary outcomes were retention in assigned and any OAT at week 24. In addition, the impact of anxiety severity on retention was examined, and assigned OAT was considered an effect modifier. RESULTS: Of the participants, 176 (65%) reported moderate-to-severe baseline anxiety. In adjusted analyses, there was no significant difference in retention between those with BAI ≥ 16 and those with BAI < 16 assigned (29% vs. 28%; odds ratio (OR) = 2.03, 95% confidence interval (CI) = 0.94-4.40; P = 0.07) or any OAT (35% vs. 34%; OR = 1.57, 95% CI = 0.77-3.21; P = 0.21). In addition, there was no significant effect modification by OAT type for retention in assigned (P = 0.41) or any OAT (P = 0.71). In adjusted analyses, greater retention in treatment was associated with BNX (vs. MMT), male gender identity (vs. female, transgender, or other), enrolment in the Quebec study site (vs. other sites), and absence of a positive urine drug screen for stimulants at baseline. CONCLUSIONS: Baseline anxiety severity did not significantly impact retention in OAT for adults with POUD, and there was no significant effect modification by OAT type. However, the overall retention rates were low, highlighting the need to develop new strategies to minimize the risk of attrition from treatment. CLINICAL TRIAL REGISTRATION: This study was registered in ClinicalTrials.gov (NCT03033732).

Socioeconomic marginalization and risk of overdose in a community-recruited cohort of people who use drugs: A longitudinal analysis.

BACKGROUND: Poverty and socioeconomic disadvantage are important contributors to drug-related harm, but their precise role in overdose risk remains poorly understood. We sought to examine linkages between socioeconomic marginalization and non-fatal overdose risk in a community deeply affected by the ongoing drug poisoning crisis. METHODS: This observational study used data derived from two community-recruited prospective cohorts of people who use drugs (PWUD) in Vancouver, British Columbia, Canada. Generalized linear mixed-effects models were used to assess longitudinal associations between multiple dimensions of socioeconomic disadvantage and self-reported non-fatal overdose. RESULTS: Between 2014 and 2020, 1,493 participants (38.2% women; 59.6% white; 35.7% Indigenous) provided 9,968 interviews. Non-fatal overdose was reported by 32.5% of participants over the study period. In multivariable analyses, non-fatal overdose was independently associated with incarceration (adjusted odds ratios [AOR]: 1.42, 95% confidence interval [CI]: 1.08-1.88, p=0.012), homelessness (AOR: 1.57, 95%CI: 1.27-1.93, p<0.001), increased monthly income (AOR: 1.01, 95%CI: 1.00-1.01, p=0.029), and lower material security (AOR: 0.76, 95%CI: 0.67-0.88, p<0.001). We also observed differing strengths of association between illegal income generation and overdose in men (AOR: 1.84, 95%CI: 1.46-2.32, p<0.001) compared to women (AOR: 1.37, 95%CI: 1.06-1.78, p=0.016). CONCLUSION: Non-fatal overdose was positively associated with incarceration, homelessness, higher monthly income, material insecurity, and engagement illegal income generating activities, underscoring the importance of addressing the socioeconomic production of overdose risk. These initiatives may include supportive housing interventions, alternative economic supports, and broader drug policy reform.

Injecting drugs alone during an overdose crisis in Vancouver, Canada.

BACKGROUND: Settings throughout Canada and the USA continue to experience crises of overdose death due to the toxic unregulated drug supply. Injecting drugs alone limits the potential for intervention and has accounted for a significant proportion of overdose deaths, yet the practice remains understudied. We sought to examine the practice of injecting alone among people who inject drugs (PWID) in Vancouver, Canada. METHODS: Data were derived from two prospective cohorts of people who use drugs between June 2016 and November 2018. This analysis was restricted to participants who, in the previous 6 months, reported any injection drug use. Rates of injecting alone were categorized as always, usually, sometimes, or occasionally. We fit a multivariable generalized linear mixed model to identify factors associated with injecting drugs alone. RESULTS: Among 1070 PWID who contributed 3307 observations, 931 (87%) reported injecting alone at least once during the study period. In total, there were 729 (22%) reports of always injecting alone, 722 (21.8%) usually, 471 (14.2%) sometimes, 513 (15.5%) occasionally, and 872 (26.4%) never. In a multivariable model, factors positively associated with injecting drugs alone included male sex (adjusted odds ratio [AOR] 1.69; 95% confidence interval [CI] 1.20-2.37), residence in the Downtown Eastside neighbourhood (AOR 1.43; 95% CI 1.08-1.91), binge drug use (AOR 1.36; 95% CI 1.08-1.72), and experiencing physical or sexual violence or both (AOR 1.43; 95% CI 1.00-2.03). Protective factors included Indigenous ancestry (AOR 0.71; 95% CI 0.52-0.98) and being in a relationship (AOR 0.30; 95% CI 0.23-0.39). CONCLUSION: We observed that injecting alone, a key risk for overdose mortality, was common among PWID in Vancouver. Our findings underline the need for additional overdose prevention measures that are gender-specific, culturally appropriate, violence- and trauma-informed, and available to those who inject alone.

Day-to-day impact of COVID-19 and other factors associated with risk of nonfatal overdose among people who use unregulated drugs in five cities in the United States and Canada.

BACKGROUND: The COVID-19 pandemic has compounded the longstanding drug poisoning crisis in Canada and the United States (US). Research is needed to understand the contributions of COVID-19 and subsequent infection control measures. We sought to estimate the prevalence of and factors associated with nonfatal overdose among participants in nine prospective cohorts of people who use unregulated drugs (PWUD) in Canada and the US. METHODS: Data were derived from nine cohorts of PWUD in urban centres in Canada (Vancouver, BC) and the US (Baltimore, MD; Miami, FL; Chicago, IL; Los Angeles, CA) between May, 2020 and April, 2021. Multivariable logistic regression was used to identify factors associated with nonfatal overdose among participants who used unregulated drugs in the past month. RESULTS: Among 885 participants (including 253 females), 41 (4.6 %) experienced a non-fatal overdose in the past month, and 453 (51.2 %) reported being highly impacted day-to-day by the pandemic. In multivariable analyses, people who experienced a non-fatal overdose were more likely to be female (Adjusted Odds Ratio [AOR]=2.18;95 % Confidence Interval [CI]=1.10-4.30); unstably housed/homeless (AOR=2.16;95 % CI=1.11-4.26); engaged in medications for opioid use disorder (AOR=2.45;95 % CI=1.19-4.97); and highly impacted day-to-day (AOR=2.42;95 % CI=1.22-5.10). CONCLUSION: Our findings may reflect characteristics of participants who experienced a compounding of vulnerabilities during the pandemic and thus are vulnerable to overdose, including women, those unstably housed/homeless, and those who perceived their daily lives were highly impacted by the pandemic. Multi-level interventions are needed to remediate the vulnerabilities and address the main driver of poisoning crisis.

Factors associated with self-reported avoidance of harm reduction services during the COVID-19 pandemic by people who use drugs in five cities in the United States and Canada.

BACKGROUND: This study examines individual-level factors associated with avoiding two important health services for people who use drugs-medications for treatment of opioid use disorder and syringe service programs-during the first year of the COVID-19 pandemic. METHODS: Data come from two subsamples of people who use drugs who were active participants in one of nine cohort studies in Vancouver, British Columbia; Baltimore, Maryland; Los Angeles, California; Chicago, Illinois; and Miami, Florida. Participants were interviewed remotely about COVID-19-associated disruptions to healthcare. We estimated the association of demographic, social, and health factors with each outcome using logistic regression among 702 participants (medication analysis) and 304 participants (syringe service analysis.) Analyses were repeated, stratified by city of residence, to examine geographic variation in risk. RESULTS: There were large differences between cities in the prevalence of avoiding picking up medications for opioid use disorder, with almost no avoidance in Vancouver (3%) and nearly universal avoidance in Los Angeles, Chicago, and Miami (>90%). After accounting for between-city differences, no individual factors were associated with avoiding picking up medications. The only factor significantly associated with avoiding syringe service programs was higher levels of self-reported worry about COVID-19. CONCLUSION: During the first year of the COVID-19 pandemic, geographic differences in service and policy contexts likely influenced avoidance of health and harm reduction services by people who use drugs in the United States and Canada more than individual differences between people.

Opioid agonist treatment improves progression through the HIV cascade of care among people living with HIV who use unregulated opioids.

OBJECTIVES: Opioid agonist treatment (OAT) has been shown to improve certain HIV-related treatment measures among people with HIV (PHIV) with opioid use disorder (OUD). However, there is limited data on the impacts of OAT along the whole HIV cascade of care. DESIGN AND METHODS: Using data from an ongoing cohort of PHIV who use drugs in Vancouver, Canada, we used cumulative link mixed-effects models to estimate the independent effect of OAT on achieving progressive steps in the HIV cascade among participants using unregulated opioids daily, after adjusting for confounders. RESULTS: Between 2005 and 2017, we recruited 639 PHIV regularly using opioids (median age 42 years, 59% male, 56% White), of whom 70% were on OAT at their baseline visit. Engagement in OAT showed a nonsignificant trend with higher linkage to HIV care (adjusted partial proportional odds ratio [APPO] = 1.75, 95% confidence interval [CI]: 0.83-3.69), and significantly higher cumulative odds of successfully achieving subsequent HIV cascade steps: on ART (APPO = 3.85, 95% CI: 2.33-6.37); adherent to ART (APPO = 3.15, 95% CI: 2.15-4.62); and HIV viral suppression (APPO = 2.18, 95% CI: 1.51-3.14). CONCLUSIONS: This study found a high level of OAT engagement among PHIV using unregulated opioids and that OAT engagement resulted in significantly increased progression through some of the higher steps of the HIV cascade. While these findings are encouraging, they highlight the need to reach populations off OAT to maximize the clinical and community-level benefits of ART.

Medical Detoxification for Nonopioid Substances Is Associated With Lower Likelihood of Subsequent Linkage to Substance Use Disorder Treatment.

BACKGROUND: Although factors associated with completion of medical detoxification treatment for substance use disorders (SUD) are well described, there is limited information on barriers and facilitators to subsequent linkage to SUD treatment in the community. This study aimed to evaluate correlates of successful linkage to community SUD treatment on discharge. METHODS: Data were drawn from 2 prospective cohorts of people who use unregulated drugs in Vancouver, Canada between December 2012 and May 2018. Multivariable generalized estimating equations were used to investigate factors associated with linkage to community SUD treatment in the 6-month period after attending detoxification treatment. RESULTS: Of the 264 detoxification treatment encounters contributed by 178 people who use unregulated drugs, these were most often (n = 104, 39%) related to polysubstance use, and the majority (n = 174, 66%) resulted in subsequent linkage to community treatment. In the multivariable analysis, compared to attending detoxification treatment for opioid use, attending detoxification treatment for stimulants (adjusted odds ratio [AOR] = 0.23, 95% confidence interval [CI] : 0.10-0.51) and alcohol (AOR = 0.17, 95% CI: 0.06-0.54) were associated with lower odds of subsequent linkage to community treatment. Conversely, later calendar year of detoxification treatment remained associated with higher odds (AOR = 1.23, 95% CI: 1.06-1.42). CONCLUSIONS: Only two-thirds of detoxification treatment encounters in Vancouver were subsequently linked to community SUD treatment, with those related to nonopioid substances being less likely. Findings suggest the need for tailored interventions for specific substances to improve linkage to SUD treatment in the community on discharge.

Psychedelic use is associated with reduced daily opioid use among people who use illicit drugs in a Canadian setting.

BACKGROUND: Research into the therapeutic and naturalistic uses of psychedelics for improving outcomes related to mental health disorders has generated increasing interest in recent years. While controlled clinical trials of psychedelics have signaled benefits for treating substance use disorders, this area has not been well studied in the context of naturalistic psychedelic use. This study sought to investigate the possible relationship between recent naturalistic psychedelic use and subsequent daily illicit opioid use among people who use drugs (PWUD). METHODS: Data (2006-2018) were drawn from three harmonized prospective cohorts of community-recruited PWUD in Vancouver, Canada. We used multivariable generalized linear mixed-effects modeling (GLMM) to estimate the independent association between psychedelic use and subsequent daily illicit opioid use. RESULTS: Among 3813 PWUD at baseline, 1093 (29%) reported daily use of illicit opioids and 229 (6%) reported psychedelic use in the past six months. Over study follow-up after adjusting for a range of potential confounders, psychedelic use remained independently associated with a significantly reduced odds of subsequent daily opioid use (Adjusted Odds Ratio: 0.45; 95% Confidence Interval: 0.29 to 0.70). CONCLUSION: While confirmation in other settings is required, these findings align with growing evidence that psychedelic use may be associated with detectable reductions in subsequent substance use including illicit opioid use.

A drug-related Good Samaritan Law and calling emergency medical services for drug overdoses in a Canadian setting.

BACKGROUND: People who use drugs (PWUD) are known to fear calling emergency medical services (EMS) for drug overdoses. In response, drug-related Good Samaritan Laws (GSLs) have been widely adopted in the USA and Canada to encourage bystanders to call emergency medical services (EMS) in the event of a drug overdose. However, the effect of GSLs on EMS-calling behaviours has been understudied. We sought to identify factors associated with EMS-calling, including the enactment of the Canadian GSL in May 2017, among PWUD in Vancouver, Canada, a setting with an ongoing overdose crisis. METHODS: Data were derived from three prospective cohort studies of PWUD in Vancouver in 2014-2018. Multivariable logistic regression was used to determine factors associated with EMS-calling among PWUD who witnessed an overdose event. An interrupted time series (ITS) analysis was employed to assess the impact of GSL on monthly prevalence of EMS-calling. RESULTS: Among 540 eligible participants, 321 (59%) were males and 284 (53%) reported calling EMS. In multivariable analysis, ever having administered naloxone three or more times (adjusted odds ratio [AOR] 2.00; 95% confidence interval [CI] 1.08-3.74) and residence in the Downtown Eastside (DTES) neighbourhood of Vancouver (AOR 1.96; 95% CI 1.23-3.13) were positively associated with EMS-calling, while living in a single occupancy hotel (SRO) was negatively associated with EMS-calling (AOR 0.51; 95% CI 0.30-0.86). The post-GSL enactment period was not associated with EMS-calling (AOR 0.81; 95% CI 0.52-1.25). The ITS found no significant difference in the monthly prevalence of EMS-calling between pre- and post-GSL enactment periods. CONCLUSION: We observed EMS being called about half the time and the GSL did not appear to encourage EMS-calling. We also found that individuals living in SROs were less likely to call EMS, which raises concern given that fatal overdose cases are concentrated in SROs in our setting. The link between many naloxone administrations and EMS-calling could indicate that those with prior experience in responding to overdose events were more willing to call EMS. Increased efforts are warranted to ensure effective emergency responses for drug overdoses among PWUD.

Childhood physical abuse and subsequent violent victimization among people who use illegal drugs in Vancouver, Canada.

BACKGROUND: Violent victimization is common among people who use illegal drugs (PWUD) and is a source of significant health-related harm. However, little attention has been paid to how antecedent childhood trauma among PWUD may contribute to the risk of victimization in adulthood. OBJECTIVE: This study sought to examine the relationship between childhood physical abuse and victimization by physical assault among adult PWUD. PARTICIPANTS AND SETTING: Data were derived from three prospective cohorts of PWUD in Vancouver, Canada between 2005 and 2018. METHODS: Childhood physical abuse was assessed using the Childhood Trauma Questionnaire. Generalized linear mixed modeling was used to estimate the relationship between childhood physical abuse and subsequent violent victimization, after adjustment for potential confounders. RESULTS: Among 2960 PWUD, including 1018 (34.39%) female participants, 1030 (34.8%) participants reported a history of moderate to severe childhood physical abuse, and 949 (32.06%) participants reported recent violent victimization at baseline. In a multivariate analysis, childhood physical abuse (Adjusted Odds Ratio [AOR] = 1.34, 95% confidence interval [CI]: 1.23-1.46) remained independently associated with violent victimization after adjustment for potential confounders. CONCLUSIONS: This study found a high prevalence of childhood physical abuse and that this was associated with a higher risk of subsequent violent victimization among PWUD in this setting. Greater support for PWUD with a history of childhood physical abuse is needed to decrease existing vulnerability to violence, including screening for and treatment of childhood trauma and related violence prevention.

Effect of alternative income assistance schedules on drug use and drug-related harm: a randomised controlled trial.

BACKGROUND: The synchronised monthly disbursement of income assistance, whereby all recipients are paid on the same day, has been associated with increases in illicit drug use and serious associated harms. This phenomenon is often referred to as the cheque effect. Because payment variability can affect consumption patterns, this study aimed to assess whether these harms could be mitigated through a structural intervention that varied income assistance payment timing and frequency. METHODS: This randomised, parallel group trial was done in Vancouver, Canada, and enrolled recipients of income assistance whose drug use increased around payment days. The recipients were randomly assigned 1:2:2 to a control group that received monthly synchronised income assistance payments on government payment days, a staggered group in which participants received single desynchronised monthly income assistance payments, or a split and staggered group in which participants received desynchronised income assistance payments split into two instalments per month, 2 weeks apart, for six monthly payment cycles. Desynchronised payments in the intervention groups were made on individual payment days outside the week of the standard government schedules. Randomisation was through a pre-established stratified block procedure. Investigators and statisticians were masked to group allocation, but participants and front-line staff were not. Complete final results are reported after scheduled interim analyses and the resulting early stoppage of recruitment. Under intention-to-treat specifications, generalised linear mixed models were used to analyse the primary outcome, which was escalations in drug use, predefined as a 40% increase in at least one of: use frequency; use quantity; or number of substances used during the 3 days after government payments. Secondary analyses examined analogous drug use outcomes coinciding with individual payments as well as exposure to violence. This trial is registered with ClinicalTrials.gov, NCT02457949. FINDINGS: Between Oct 27, 2015, and Jan 2, 2019, 45 participants were enrolled to the control group, 72 to the staggered group, and 77 to the split and staggered group. Intention-to-treat analyses showed a significantly reduced likelihood of increased drug use coinciding with government payment days, relative to the control group, in the staggered (adjusted odds ratio 0·38, 95% CI 0·20-0·74; p=0·0044) and split and staggered (0·44, 0·23-0·83; p=0·012) groups. Findings were consistent in the secondary analyses of drug use coinciding with individual payment days (staggered group 0·50, 0·27-0·96, p=0·036; split and staggered group 0·49, 0·26-0·94, p=0·030). However, secondary outcome analyses of exposure to violence showed increased harm in the staggered group compared with the control group (2·71, 1·06-6·91, p=0·037). Additionally, 51 individuals had a severe or life-threatening adverse event and there were six deaths, none of which was directly attributed to study participation. INTERPRETATION: Complex results indicate the potential for modified income assistance payment schedules to mitigate escalations in drug use, provided measures to address unintended harms are also undertaken. Additional research is needed to clarify whether desynchronised schedules produce other unanticipated consequences and if additional measures could mitigate these harms. FUNDING: Canadian Institutes of Health Research, Providence Health Care Research Institute, Peter Wall Institute for Advanced Research, Michael Smith Foundation for Health Research.

A paradox of need: Gaps in access to dental care among people who use drugs in Canada's publicly funded healthcare system.

In Canada, publicly funded healthcare provides no-cost access to a large but not comprehensive suite of services. Dental care is largely funded by private insurance or patients, creating employment- and income-dependent gaps in care access. Difficulties accessing dental care may be amplified among vulnerable populations, including people who use drugs (PWUD), who may experience greater dental need due to side effects of substance use and health comorbidities, as well as barriers to care. Using data collected between 2014 and 2018 from two ongoing prospective cohort studies of PWUD in Vancouver, Canada, the aim of this study was to explore factors associated with dental care access. Among 1,638 participants, 246 participants (15%) reported never or only occasionally accessing adequate dental care. In generalised linear mixed-effects models, results showed significant negative associations between accessing dental care and using opioids (Adjusted Odds Ratios [AOR] = 0.73, 95% Confidence Interval [CI] = 0.58-0.91), methamphetamine (AOR = 0.75, 95% CI = 0.59-0.95) and cannabis (AOR = 0.78, 95% CI = 0.63-0.97), as well experiencing homelessness (AOR = 0.54, 95% CI = 0.42-0.70) and street-based income generation (AOR = 0.75, 95% CI = 0.59-0.94). There were significant positive associations between adequate dental care and accessing opioid agonist treatment (OAT) for opioid dependence (AOR = 1.36, 95% CI = 1.07-1.72) and receiving income assistance (AOR = 1.70, 95% CI = 1.05-2.77). These results highlight specific substance use patterns and structural exposures that may hinder dental care access, as well as how direct and indirect benefits of income assistance and OAT may improve access. These findings provide support for recent calls to expand healthcare coverage and address dental care inequities.

Cannabis use is associated with reduced risk of exposure to fentanyl among people on opioid agonist therapy during a community-wide overdose crisis.

BACKGROUND: The ongoing opioid overdose crisis is driven largely by exposure to illicitly-manufactured fentanyl. Preliminary observational and experimental research suggests that cannabis could potentially play a role in reducing use of prescription opioids among individuals with chronic pain. However, there is limited data on the effects of cannabis on illicit opioid consumption, particularly fentanyl, especially among individuals on opioid agonist therapy (OAT). We sought to assess the longitudinal association between cannabis use and exposure to fentanyl among people on OAT. METHODS: Data were drawn from two community-recruited prospective cohorts of people who use drugs in Vancouver, Canada. We used generalized linear mixed-effects modeling, adjusted by relevant confounders, to investigate the relationship between cannabis use and recent fentanyl exposure (both assessed by urine drug testing) among participants on OAT between 2016 and 2018. RESULTS: Among the 819 participants on OAT who contributed 1989 observations over the study period, fentanyl exposure was common. At the baseline interview, fentanyl was detected in a majority of participants (431, 53 %), with lower prevalence among individuals with urine drug tests positive for tetrahydrocannabinol (47 vs. 56 %, p = 0.028). Over all study interviews, cannabis use was independently associated with reduced likelihood of being recently exposed to fentanyl (Adjusted Prevalence Ratio = 0.91, 95 % Confidence Interval: 0.83 - 0.99). CONCLUSIONS: Participants on OAT using cannabis had significantly lower risk of being exposed to fentanyl. Our findings reinforce the need for experimental trials to investigate the potential benefits and risks of controlled cannabinoid administration for people on OAT.

Detecting fentanyl using point-of-care drug checking technologies: A validation study.

OBJECTIVES: Point-of-care drug checking services, wherein individuals can check the content and purity of their drugs, have emerged as a public health intervention to address the fentanyl crisis; however, there have been no rigorous evaluations of the technologies against reference standard laboratory techniques. METHODS: Two point-of-care technologies, fentanyl immunoassay strips and Fourier-Transform Infrared (FTIR) spectroscopy, were implemented at two supervised injection sites in Vancouver, Canada. We calculated sensitivity, specificity, and false negative rate for both testing methods as compared to a laboratory reference standard. RESULTS: Between October 2017 and 2018, 331 samples were sent for confirmatory testing. Immunoassay strips had a sensitivity of 87.5% and specificity of 95.2%, with a false negative rate of 12.5%. FTIR spectroscopy had a sensitivity of 72.1% and specificity of 99.0%, with a false negative rate of 27.9%. CONCLUSION: As expected, while FTIR spectroscopy can quantify concentrations on a wide array of compounds, it can only do so above the detection limit. Using FTIR spectroscopy and immunoassay strips in combination has the potential to offset the limitations of each technology when used alone.