Cannabis use and illicit opioid cessation among people who use drugs living with chronic pain.

Introduction: Amidst the opioid overdose crisis, there is interest in cannabis use for pain management and harm reduction. We investigated the relationship between cannabis use and cessation of unregulated opioid use among people who use drugs (PWUD) living with chronic pain.

Method: Data for analyses were collected from three prospective cohort studies in Vancouver, Canada.

Examining the association between fentanyl use and perceived adequacy of methadone dose: A retrospective cohort study.

Background: People exposed to fentanyl may report that the dose of methadone in the commonly accepted therapeutic range feels too low. We examined self-reported methadone dose adequacy.

Methods: We conducted a retrospective cohort study of individuals prescribed methadone at a dose of at least 60mg daily using data from three community-recruited prospective cohort studies of people who use drugs in Vancouver, Canada from December 2016 through March 2020.

Road to Recovery: protocol for a mixed-methods prospective cohort study evaluating the impact of a new model of substance use care in a Canadian setting.

Introduction: The Road to Recovery (R2R) Initiative is an innovative model of substance use care that seeks to increase treatment capacity by creating approximately 100 new addiction treatment beds to provide on-demand addiction care in Vancouver, British Columbia, for patients with substance use disorders. The new model also coordinates the region's existing clinical substance use services to support patients across a care continuum that includes traditional office-based addiction treatment and harm reduction services, early withdrawal management and more intensive abstinence-based treatment programming. To understand the impact of offering on-demand and coordinated substance use care, an observational cohort of individuals who access any R2R clinical service will be created to examine health and social outcomes over time.

Initiation and/or re-initiation of drug use among people who use drugs in Vancouver, Canada from 2021 to 2022: a prospective cohort study.

Objectives: Widespread health service disruptions resulting from the COVID-19 pandemic coincided with a dramatic increase in overdose deaths among people who use drugs (PWUD) in Vancouver, Canada. Those with a history of injection drug use are known to be at heightened risk of substance-associated harms. Drug use patterns and associated sociodemographic and health care utilization trends have been understudied in this population since the pandemic onset.

Preferred pharmaceutical-grade opioids to reduce the use of unregulated opioids: A cross-sectional analysis among people who use unregulated opioids in Vancouver, Canada.

Objectives: Many people who use drugs in the United States and Canada continue to access the contaminated unregulated drug supply, resulting in the ever-escalating overdose epidemic. In Canada, even in areas where healthcare providers are authorized to prescribe alternatives to the unregulated supply (e.g.

Barriers and Facilitators to Accessing Opioid Agonist Therapy for Street-involved Adolescents and Young Adults in Vancouver.

Objective: Opioid agonist therapy (OAT) remains the first-line therapy for people with opioid use disorder. Whereas overdose rates among adolescents and young adults (AYAs) remain high, little is known about their access to OAT. Therefore, we sought to evaluate factors that shape access to OAT among AYAs aged 14 to 26 years.

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.

Receipt of COVID-19 emergency funds and engagement in sex work during COVID-19 among people who use drugs: evidence from Vancouver, Canada.

Background: During the early period of the COVID-19 pandemic, public health orders disrupted income generation in numerous sectors and many governments provided emergency financial support. Access to government support and changes in engagement in sex work during the early period of the pandemic among people who use drugs (PWUD) are not well described. In the present study, we investigate the prevalence and correlates of engaging in sex work during the COVID-19 pandemic, among PWUD in Vancouver, Canada.

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.

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.

Longitudinal polysubstance use patterns and non-fatal overdose: A repeated measures latent class analysis.

Background: Polysubstance use (PSU) is common among people who use opioids (PWUO) and has been associated with drug-related harms. We aimed to identify latent longitudinal PSU classes among a cohort of PWUO and characterize non-fatal overdose risks among different sub-classes over time.

Methods: We used longitudinal data (2005-2018) from three ongoing prospective cohorts of people who use drugs in Vancouver, Canada.

Evaluating the agreement between different substance use recall periods in multiple HIV cohorts.

Background: This study aims to evaluate the agreement in substance use on both binary and ordinal scales between 3-month and 6-month recall periods with samples from different communities, demographic backgrounds, and HIV status.

Methods: We administered the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) to 799 participants from three different North American cohorts focused on substance use and HIV. We conducted a within-person agreement analysis by calculating the agreement levels and Kappa statistic between data collected using the 3-month recall ASSIST and 6-month custom substance use surveys as well as different terminology for each substance in multiple cohorts.

Uptake of SARS-CoV-2 vaccination among structurally-marginalized people who use drugs in Vancouver, Canada.

We sought to evaluate the rates and predictors of SARS-CoV-2 vaccination among members of a structurally-marginalized population of people who use drugs (PWUD) during a targeted, community-wide, vaccination campaign in Vancouver, Canada. Interviewer-administered data were collected from study participants between June 2021 and March 2022. Generalized estimating equation analysis was used to identify factors associated with SARS-CoV-2 vaccine uptake, ascertained through a province-wide vaccine registry.

Cannabis use to manage stimulant cravings among people who use unregulated drugs.

Background: We sought to analyze the association between cannabis use to manage stimulant cravings and self-reported changes in stimulant use among structurally marginalized people who use unregulated drugs (PWUD).

Methods: The data for this secondary analysis was collected from a cross-sectional questionnaire administered to people who concurrently use cannabis and unregulated stimulants in Vancouver, Canada. We used logistic regression models to analyze the association between cannabis use to manage stimulant cravings and self-reported changes in the frequency of stimulant use.

Police seizure of drugs without arrest among people who use drugs in Vancouver, Canada, before provincial 'decriminalization' of simple possession: a cohort study.

Background: Several jurisdictions in Canada have recently considered decriminalizing possession of illicit drugs for personal use (henceforth, simple possession) as part of their responses to the ongoing drug toxicity/overdose crisis. In this context, we sought to examine an early implementation case of a de facto depenalization policy of simple possession offences in Vancouver, Canada, that was enacted in 2006. Specifically, we characterized experiences of people who use drugs (PWUD) whose drugs were discretionally seized by police without arrest.

Cannabis use to manage opioid cravings among people who use unregulated opioids during a drug toxicity crisis.

Background: Accumulating evidence has indicated that cannabis substitution is often used as a harm reduction strategy among people who use unregulated opioids (PWUO) and people living with chronic pain. We sought to investigate the association between cannabis use to manage opioid cravings and self-reported changes in opioid use among structurally marginalized PWUO.

Methods: The data were collected from a cross-sectional questionnaire administered to PWUO in Vancouver, Canada.

Decriminalization thresholds for drug possession: A multi-criteria policy analysis framework.

Background: Decriminalization of personal possession of drugs has been proposed as an approach to mitigate the harms of drug prohibition. Despite growing interest, particularly in Canadian settings, analyses of approaches to defining the parameters of what constitutes personal possession within decriminalization models are lacking. Using the Province of British Columbia, Canada, as a case study, we undertook an evidence-based multi-criteria policy analysis of three models for defining personal possession: 1) a model that defines personal possession as the absence of evidence of drug trafficking; 2) a cumulative threshold of 15 grams; and 3) a cumulative threshold of 2.

First-line opioid agonist treatment as prevention against assisting others in initiating injection drug use: A longitudinal cohort study of people who inject drugs in Vancouver, Canada.

Background: Among people who inject drugs, frequent injecting and experiencing withdrawal are associated with facilitating others' first injections. As these factors may reflect an underlying substance use disorder, we investigated whether first-line oral opioid agonist treatment (OAT; methadone or buprenorphine/naloxone) reduces the likelihood that people who inject drugs help others initiate injecting.

Methods: We used questionnaire data from semi-annual visits between December 2014-May 2018 on 334 people who inject drugs with frequent non-medical opioid use in Vancouver, Canada.

Food insecurity during the COVID-19 pandemic who use drugs in Vancouver, Canada.

Objective: To examine prevalence and factors associated with food insecurity among people who use drugs (PWUD) during the first year of the COVID-19 pandemic and the overdose crisis.

Design: This cross-sectional study employs multivariable logistic regression to identify factors associated with self-reported food insecurity.

Participants: PWUD who are part of three community-recruited cohorts.

Latent polydrug use patterns and the provision of injection initiation assistance among people who inject drugs in three North American settings.

Introduction: We sought to identify latent profiles of polysubstance use patterns among people who inject drugs in three distinct North American settings, and then determine whether profile membership was associated with providing injection initiation assistance to injection-naïve persons.

Methods: Cross-sectional data from three linked cohorts in Vancouver, Canada; Tijuana, Mexico; and San Diego, USA were used to conduct separate latent profile analyses based on recent (i.e.

Longitudinal latent polysubstance use patterns among a cohort of people who use opioids in Vancouver, Canada.

Introduction: Polysubstance use (PSU) practices are increasing among people who use opioids (PWUO). However, several aspects of longitudinal PSU patterns among PWUO remain understudied. This study aims to identify person-centred longitudinal patterns of PSU among a cohort of PWUO.

Impacts of the COVID-19 pandemic on enrollment in medications for opioid use disorder (MOUD) in Vancouver, Canada: An interrupted time series analysis.

Background: In anticipation of COVID-19 related disruptions to opioid use disorder (OUD) care, new provincial and federal guidance for the management of OUD and risk mitigation guidance (RMG) for prescription of pharmaceutical opioids were introduced in British Columbia, Canada, in March 2020. This study evaluated the combined impacts of the COVID-19 pandemic and counteracting OUD policies on enrollment in medications for OUD (MOUD).

Methods: Using data from three cohorts of people with presumed OUD in Vancouver, we conducted an interrupted time series analysis to estimate the combined effects impact of the COVID-19 pandemic and counteracting OUD policies on the prevalence of enrollment in MOUD overall, as well as in individual MOUDs (methadone, buprenorphine/naloxone, slow-release oral morphine) between November 2018 and November 2021, controlling for pre-existing trends.