The impact of the COVID-19 pandemic on people who use drugs in three Canadian cities: a cross-sectional analysis.

Background: The COVID-19 pandemic had a disproportionate impact on the health and wellbeing of people who use drugs (PWUD) in Canada. However less is known about jurisdictional commonalities and differences in COVID-19 exposure and impacts of pandemic-related restrictions on competing health and social risks among PWUD living in large urban centres.

Methods: Between May 2020 and March 2021, leveraging infrastructure from ongoing cohorts of PWUD, we surveyed 1,025 participants from Vancouver (n = 640), Toronto (n = 158), and Montreal (n = 227), Canada to describe the impacts of pandemic-related restrictions on basic, health, and harm reduction needs.

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.

Re-incarceration and associated social, structural and behavioural factors among people who use drugs in an urban Canadian setting.

Background: People who use drugs (PWUD) are disproportionately incarcerated, however little is known about specific substance use, social and structural factors associated with re-incarceration among PWUD. We aimed to identify the socio-structural and substance use factors associated with re-incarceration among structurally-marginalized PWUD.

Methods: We used longitudinal data from two prospective cohorts of PWUD in Vancouver, Canada.

Implications of Cannabis Legalization on Substance-Related Benefits and Harms for People Who Use Opioids: A Canadian Perspective.

In 2018, Canada enacted the , becoming only the second country (after Uruguay) to legalize the recreational consumption of cannabis. Although there is ongoing global disagreement on the risk-benefit profile of cannabis with increasing legalization in many parts of the world, the evidence of rising cannabis use prevalence postlegalization has been consistent. In contrast, postlegalization changes in various cannabis-related metrics have been inconsistent in Canada and other parts of the world.

Shifts in substance use patterns among a cohort of people who use opioids after delisting of OxyContin in BC, Canada: An interrupted time series study.

Background: OxyContin was delisted from Canadian provincial drug formularies in March 2012 and replaced with a reformulated tamper-resistant form of oxycodone (i.e., OxyNeo).

Use of Cannabis as a Harm Reduction Strategy Among People Who Use Drugs: A Cohort Study.

While substance use contributes to a substantial burden of disease, access to evidence-based harm reduction interventions remains limited or inaccessible. Preliminary research suggests that some individuals use cannabis to reduce the harms associated with their use of other substances, including opioids and stimulants. This study examines factors associated with the self-reported use of cannabis for harm reduction among people who use drugs (PWUD).

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.

Assessing the Temporality Between Transitions onto Opioid Agonist Therapy and Engagement with Antiretroviral Therapy in a Cohort of HIV-Positive People Who Use Opioids Daily.

A robust evidence-base describes the beneficial association between opioid agonist therapy (OAT) and HIV-related outcomes among people living with HIV and opioid use disorder. While some evidence suggests the stabilizing effect of OAT on antiretroviral therapy (ART) treatment engagement, less is understood about the potential for an inverse relationship. We sought to examine the relationship between transitions in ART engagement and transitions onto OAT.

The Cannabis-Dependent Relationship Between Methadone Treatment Dose and Illicit Opioid Use in a Community-Based Cohort of People Who Use Drugs.

Methadone maintenance treatment (MMT) is an effective treatment for opioid use disorder. However, subtherapeutic dosing may lead to continued opioid use by failing to suppress opioid withdrawal and craving. Preclinical and pilot experimental research suggests that cannabinoids may reduce opioid withdrawal and craving.

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).

The use of diverted pharmaceutical opioids is associated with reduced risk of fentanyl exposure among people using unregulated drugs in Vancouver, Canada.

Background: Although non-medical use of pharmaceutical opioids (POs) is associated with a number of risks, in the context of the opioid-overdose crisis, it may have the secondary benefit of decreasing the risk of exposure to more potent opioids from unregulated sources. The aim of this study was to assess the effects of using diverted POs on fentanyl exposure.

Methods: Using data from two prospective community-recruited cohorts of people who use drugs (PWUD) in Vancouver, Canada, we estimated the independent relationship between using diverted POs and fentanyl exposure (assessed through urine drug test [UDT]) between 2016 and 2018.

Greater Pain Severity is Associated with Inability to Access Addiction Treatment Among a Cohort of People Who Use Drugs.

Aim: Given that co-occurring pain is prevalent among people who use drugs (PWUD), we sought to explore the effect of pain severity on accessing addiction treatment.

Methods: Data were derived from two prospective cohort studies of PWUD in Vancouver, Canada from June 2014 to May 2016. Multivariable generalized linear mixed-effects multiple regression (GLMM) analyses were used to investigate the association between average pain severity and self-reported inability to access addiction treatment.

Assisted injection within supervised injection services: Uptake and client characteristics among people who require help injecting in a Canadian setting.

Background: People who require help injecting illicit drugs experience elevated rates of a range of health-related harms, including overdose and acquisition of blood-borne pathogens. In response, some supervised injection services (SIS) in Canada have begun to permit clients to be physically injected by fellow clients or staff members. However, little is known about uptake and characteristics of clients who engage in this practice.

Long term pre-treatment opioid use trajectories in relation to opioid agonist therapy outcomes among people who use drugs in a Canadian setting.

Background: Opioid agonist therapy (OAT) models are generally provided without consideration of how pre-treatment characteristics may be associated with outcome. Therefore, we aimed to first characterize longitudinal trajectories of opioid use before initiating OAT. Then we explored the impact of OAT on opioid use across these pre-treatment trajectories.

Changes in substance use in relation to opioid agonist therapy among people who use drugs in a Canadian setting.

Background: Although previous studies have shown that opioid agonist therapy (OAT) is linked to reductions in illicit opioid use, less is known about how OAT impacts the use of other psychoactive substances. We aimed to examine the changes in use of different substances by comparing patterns before and after initiating OAT.

Methods: Data for this study was derived from three ongoing prospective cohorts involving people who use drugs in Vancouver, Canada from 1996 to 2018.

Supervised injection facility use and exposure to violence among a cohort of people who inject drugs: A gender-based analysis.

Background: Supervised injection facilities (SIFs) have been established in many settings, in part to reduce risks associated with injecting in public, including exposure to violence. However, the relationship between SIF use and experiencing violence has not yet been thoroughly evaluated. We sought to longitudinally examine the gender-specific relationship between SIF use and exposure to violence among people who inject drugs (PWID) in a Canadian setting.

The impact of methadone maintenance therapy on access to regular physician care regarding hepatitis C among people who inject drugs.

Background & Aims: People who inject drugs (PWID) living with hepatitis C virus (HCV) infection often experience barriers to accessing HCV treatment and care. New, safer and more effective direct-acting antiviral-based therapies offer an opportunity to scale-up HCV-related services. Methadone maintenance therapy (MMT) programs have been shown to be effective in linking PWID to health and support services, largely in the context of HIV.

Prevalence and predictors of facing a legal obligation to disclose HIV serostatus to sexual partners among people living with HIV who inject drugs in a Canadian setting:a cross-sectional analysis.

Background: In October 2012, the Canadian Supreme Court ruled that people living with HIV must disclose their HIV status before sex that poses a "realistic possibility" of HIV transmission, clarifying that in circumstances where condom-protected penile-vaginal intercourse occurred with a low viral load (< 1500 copies/mL), the realistic possibility of transmission would be negated. We estimated the proportion of people living with HIV who use injection drugs who would face a legal obligation to disclose under these circumstances.

Methods: : We used cross-sectional survey data from a cohort of people living with HIV who inject drugs.

Benzodiazepine Use and Hepatitis C Seroconversion in a Cohort of Persons Who Inject Drugs.

Objectives: To examine the relationship between benzodiazepine (BZD) use and HCV seroconversion in 2 linked prospective cohorts of persons who inject drugs (PWID).

Methods: We examined prospective cohorts of 440 PWID (baseline BZD users: n = 102; 23.2%) from the AIDS Care Cohort to Evaluate Access to Survival Services (ACCESS) and the Vancouver Injection Drug Users Study (VIDUS) cohorts, followed-up from 1996 to 2013 in Vancouver, Canada.

Gender differences in access to methadone maintenance therapy in a Canadian setting.

Introduction And Aims: Methadone maintenance therapy (MMT) is an evidence-based treatment for opioid addiction. While gender differences in MMT pharmacokinetics, drug use patterns and clinical profiles have been previously described, few studies have compared rates of MMT use among community-recruited samples of persons who inject drugs (PWID).

Design And Methods: The present study used prospective cohorts of PWID followed between May 1996 and May 2013 in Vancouver, British Columbia, Canada.

Injection drug use and HIV antiretroviral therapy discontinuation in a Canadian setting.

We investigated whether drug-related behaviors predicted antiretroviral therapy (ART) discontinuation among a cohort of injection drug users (IDU) in a Canadian setting. Cox regression analyses were used to investigate the impact of drug use patterns on rates of ART discontinuation among a sample of HIV-positive IDU in Vancouver, Canada between May 1996 and April 2008. In total, 408 HIV-positive IDU initiated ART during the study period, among whom 257 (63.

Estimated drug overdose deaths averted by North America's first medically-supervised safer injection facility.

Background: Illicit drug overdose remains a leading cause of premature mortality in urban settings worldwide. We sought to estimate the number of deaths potentially averted by the implementation of a medically supervised safer injection facility (SIF) in Vancouver, Canada.

Methodology/principal Findings: The number of potentially averted deaths was calculated using an estimate of the local ratio of non-fatal to fatal overdoses.