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. RESULTS: Among participants, awareness of COVID-19 protective measures was high; however, between 10 and 24% of participants in each city-specific sample reported being unable to self-isolate. Overall, 3-19% of participants reported experiencing homelessness after the onset of the pandemic, while 20-41% reported that they went hungry more often than usual. Furthermore, 8-33% of participants reported experiencing an overdose during the pandemic, though most indicated no change in overdose frequency compared the pre-pandemic period. Most participants receiving opioid agonist therapy in the past six months reported treatment continuity during the pandemic (87-93%), however, 32% and 22% of participants in Toronto and Montreal reported missing doses due to service disruptions. There were some reports of difficulty accessing supervised consumption sites in all three sites, and drug checking services in Vancouver. CONCLUSION: Findings suggest PWUD in Canada experienced difficulties meeting essential needs and accessing some harm reduction services during the COVID-19 pandemic. These findings can inform preparedness planning for future public health emergencies.

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. METHODS: Data derived from three harmonized cohorts of PWUD. Using multivariable logistic regression, we characterized factors associated with engaging in sex work in the last month between July 17 and November 30, 2020. Reports of changes in frequency of engagement in sex work since the pandemic were also collected. RESULTS: Of the 864 individuals included in this analysis, 55 (6.4%) reported sex work engagement in the last month. Among these participants, 40.7% reported receiving COVID-19 income support in the past month vs. 52.7% of the rest of the sample, though receipt of income support in the past six months was similar between the two groups (72.2% vs. 75.7%, p = 0.624). In multivariable analysis, receipt of financial support in the last month was negatively associated with engagement in sex work in the last month (adjusted odds ratio [AOR] = 0.44 [95% confidence interval [CI]: 0.24-0.81]). Among 69 participants who responded to a question regarding changes in engagement in sex work, 38 (55.1%) reported a decrease, 11 (15.9%) reported an increase, 19 (27.5%) reported no change, and 1 (1.4%) reported cessation. CONCLUSIONS: Findings document that engagement in sex work appears to have declined early in the pandemic. Participants who received income support in the past month were less likely to report recent engagement in sex work. Findings suggest that recent receipt of income support may have contributed to reductions in engagement in sex work. Additional investigation is warranted.

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.

Perceptions of provider awareness of traditional and cultural treatments among Indigenous people who use unregulated drugs in Vancouver, Canada.

INTRODUCTION: Indigenous people who use unregulated drugs (IPWUD) face significant barriers to care, including sparse availability of culturally safe health services. Integrating Indigenous traditional and cultural treatments (TCT) into health service delivery is one way to enhance culturally safe care. In a Canadian setting that implemented cultural safety reforms, we sought to examine the prevalence and correlates of client perceptions of primary care provider awareness of TCT among IPWUD. METHODS: Data were derived from two prospective cohort studies of PWUD in Vancouver, Canada between December 2017 and March 2020. A generalized linear mixed model with logit-link function was used to identify longitudinal factors associated with perceived provider awareness of TCT. RESULTS: Among a sample of 507 IPWUD who provided 1200 survey responses, a majority (n = 285, 56%) reported their primary care provider was aware of TCT. In multiple regression analyses, involvement in treatment decisions always (Adjusted Odds Ratio [AOR] = 3.6; 95% confidence interval [CI]: 1.6-7.8), involvement in treatment decisions most or some of the time (AOR = 3.3; 95% CI: 1.4-7.7), comfort with provider or clinic (AOR = 2.7; 95% CI: 1.5-5.0), and receiving care from a social support worker (AOR = 1.5; 95% CI: 1.0-2.1) were positively associated with provider awareness of TCT. CONCLUSION: We found high levels of perceived provider awareness of TCT and other domains of culturally safe care within a cohort of urban IPWUD. However, targeted initiatives that advance culturally safe care are required to improve healthcare and health outcomes for IPWUD, who continue to bear a disproportionate burden of substance use harms.

Patterns of Socioeconomic Marginalization among People Who Use Drugs: A Gender-Stratified Repeated Measures Latent Class Analysis.

Socioeconomic factors are important correlates of drug use behaviors and health-related outcomes in people who use drugs (PWUD) residing in urban areas. However, less is known about the complex overlapping nature of socioeconomic conditions and their association with a range of individual, drug use, and health-related factors in men and women who use drugs. Data were obtained from two community-recruited prospective cohorts of PWUD. Using a gender-stratified approach, we conducted repeated measures latent class analyses (RMLCA) to identify discrete latent socioeconomic subgroups. Multivariable generalized estimating equations were then used to identify correlates of class membership. Between June 2014 and December 2018, RMLCA of 9844 observations from 1654 participants revealed five distinct patterns of socioeconomic status for both men and women. These patterns were primarily distinguished by variations in income, material and housing security, income generation activity, exposure to violence, criminal justice involvement, and police contact. Across gender, progressive increases in exposure to multiple dimensions of socioeconomic disadvantage were found to be associated with frequent use of opioids and stimulants, accessing social services, and being hepatitis C virus antibody-positive. Similar but less congruent trends across gender were observed for age, binge drug use, engagement with opioid agonist therapy, and living with HIV. Gendered patterns of multiple and overlapping dimensions of socioeconomic adversity aligned with patterns of frequent drug use and health-related concerns, highlighting priority areas for gender-inclusive, multilevel responses to mitigate health disparities and meet the diverse socioeconomic needs of urban-dwelling men and women who use drugs.

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.

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. The primary outcome of interest was self-reported non-fatal overdose during the past six months. The primary exposure of interest was longitudinal PSU patterns among PWUO, obtained from repeated measures latent class analysis (RMLCA) of weekly substance use-related outcome indicators. Multivariable generalized estimating equations models were built to assess the association between latent PSU class membership and non-fatal overdose, adjusting for potential sociodemographic, behavioural, and structural confounders. RESULTS: 2627 PWUO were included in the analysis, and 1094 (41.6 %) had experienced at least one non-fatal overdose during the study period. RMLCA revealed five distinct latent longitudinal PSU classes, including low/infrequent use (Class 1; 30 %), primarily opioid and methamphetamine use (Class 2; 22 %), primarily cannabis use (Class 3; 15 %), primarily opioid and crack use (Class 4; 29 %), and frequent PSU (Class 5; 4 %). In comparison with Class 1 (low), membership in all latent PSU classes except Class 3 (cannabis) was associated with increased odds of non-fatal overdose: Class 2 (opioids + meth) vs. Class 1 (Adjusted odds ratios [aOR] = 2.20, 95 % confidence intervals [CI]: 1.51-3.22), Class 4 (opioids + crack) vs. Class 1 (aOR = 1.06, 95 % CI: 0.85-1.33), and Class 5 (frequent) vs. Class 1 (aOR = 2.39, 95 % CI: 1.92-2.97). CONCLUSION: Our findings highlighted the heterogeneous characteristics of PWUO in terms of patterns of PSU and non-fatal overdose risk. The diverse nature of PWUO and the potential additive or multiplicative impact of using several substances on overdoses should be reflected across the substance use treatment continuum and care provision.

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. RESULTS: For all drugs studied, the agreement on the binary use or ordinal frequency of use metrics showed a high agreement level between 80.4% and 97.9% and an adequate adjusted kappa value between 0.61 and 0.96, suggesting substantial agreement. According to the agreement criteria we proposed, substance use data collected using different recall periods and with variation in drug names can be harmonized across cohorts. CONCLUSIONS: This study is the first to evaluate the feasibility of data harmonization of substance use by demonstrating high level of agreement between different recall periods in different cohorts. The results can inform data harmonization efforts in consortia where data are collected from cohorts using different questions and recall periods.

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. RESULTS: In total, 297 individuals were included in the present study. Cannabis use to manage stimulant cravings was reported by 134 (45.1 %) participants and 104 (77.6 %) of these participants reported decreasing their stimulant use during periods of cannabis use. In the multivariable logistic regression analysis, cannabis use to manage stimulant cravings (adjusted Odds Ratio [aOR] = 0.24, 95 % confidence interval [CI]: 0.10, 0.56) was significantly associated with self-reported reductions in stimulant use. In the sub-analyses, cannabis use to manage stimulant cravings was significantly associated with reduced stimulant use among people who used crystal methamphetamine daily (aOR = 0.08, 95 % CI: 0.02-0.37) and was not significantly associated with reduced stimulant use among people who used crack/cocaine daily (aOR = 0.33, 95 % CI: 0.04-2.86). CONCLUSIONS: These findings indicate that cannabis use to manage stimulant cravings is a common harm reduction strategy and suggest that this may be an effective strategy to reduce stimulant use among some PWUD.

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. Among 223 PWUD, 107 (48.0%) reported receipt of at least two SARS-CoV-2 vaccine doses at baseline and this increased to 151 (67.7%) by the end of the study period. Using social media as a source of vaccine information was negatively associated with SARS-CoV-2 vaccine uptake (Adjusted odds ratio [AOR] 0.27, 95% confidence interval [CI] 0.09-0.81) and HIV seropositivity (AOR 2.68, 95% CI 1.12-6.39) and older age (AOR 1.27, 95% CI 1.07-1.51) were positively associated with SARS-CoV-2 vaccine uptake. These findings suggest that the targeted vaccination campaign in Vancouver may be an effective model to promote SARS-CoV-2 vaccination in other jurisdictions. However, using social media as a source of vaccine information likely reduced SARS-CoV-2 vaccine uptake in PWUD arguing for further efforts to promote accessible and evidence-based vaccine information among marginalized populations.

Evaluating the effectiveness and cost-effectiveness of a digital, app-based intervention for depression (VMood) in community-based settings in Vietnam: Protocol for a stepped-wedge randomized controlled trial.

The COVID-19 pandemic has amplified mental health problems and highlighted inequitable gaps in care worldwide. In response there has been an explosion of digital interventions such as smartphone applications ("apps") to extend care. The objective of this trial is to evaluate the effectiveness and cost-effectiveness of a digital depression intervention (VMood), delivered via a smartphone app. VMood is adapted from an in-person intervention that was delivered by non-specialist providers and shown to be effective in the Vietnamese context in our previous trial (2016-2019). A stepped-wedge, randomized controlled trial will be conducted across eight provinces in Vietnam. Adults aged 18 years and over will be recruited through community-based primary care centres and screened for depression using the embedded Patient Health Questionnaire-9 (primary outcome measure). Participants scoring 10-19, indicating depression caseness, will be randomly allocated to the intervention or control group until the target of 336 is reached. Secondary outcome measures will examine the effect of the intervention on commonly co-occuring anxiety, quality of life and work productivity, along with use of alcohol and tobacco products. Assessments will be administered through an online survey platform (REDCap) at baseline, and at every 3 months until 3 months post-intervention. Intervention-group participants will receive VMood for a 3-month period, with online support provided by social workers. Control-group participants will receive a limited version of the app until they cross into the intervention group. Generalized Linear Mixed-effect Models for clustered measures will be used for all outcomes data. We will conduct a cost-effectiveness analysis alongside the trial to capture VMood's costs and benefits. This trial will provide evidence on the effectiveness and cost-effectiveness of a digital mental health intervention adapted from an in-person intervention. This trial will also contribute important information to the growing and promising field of digital mental health. Trail regulation. Registered at ClinicalTrials.gov, identifier [NCT05783531].

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. METHODS: Data were derived from three prospective cohorts of community-recruited PWUD in Vancouver over 16 months in 2019-2021. We conducted multivariable generalized estimating equations analyses to determine the prevalence of and factors associated with drug seizure. Sub-analyses used data collected in 2009-2012 and examined the trends over time. RESULTS: Among 995 participants who were interviewed in 2019-2021, 63 (6.3%) had their drugs seized by police at least once in the past 6 months. In multivariable analyses, factors significantly associated with drug seizure included: homelessness (adjusted odds ratio [AOR]: 1.98; 95% confidence interval [CI] 1.09-3.61), working in the unregulated drug market (AOR: 4.93; 95% CI 2.87-8.49), and naloxone administration (AOR: 2.15; 95% CI 1.23-3.76). In 2009-2012, 67.8% reported having obtained new drugs immediately after having their drugs seized by police. Odds of drug seizure were not significantly different between the two time periods (2019-2021 vs. 2009-2012) (AOR: 0.93; 95% CI: 0.64-1.35). CONCLUSIONS: Despite the depenalization policy, the Vancouver Police Department has continued to seize illicit drugs from PWUD, even in cases where no arrest occurred. This policing practice may create health and safety risks for PWUD as it forces PWUD to increase the engagement with the unregulated illicit drug market. Our findings support calls for abolishing this often-undocumented discretionary policing practice that may exacerbate ongoing health inequities and interfere with peer-based overdose prevention efforts.

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. We estimated the effect of current first-line OAT on subsequent injection initiation assistance provision (i.e., helped someone initiate injecting in the following six months) using inverse-probability-weighted estimation of repeated measures marginal structural models to reduce confounding and informative censoring by time-fixed and time-varying covariates. Results: By follow-up visit, 54-64% of participants reported current first-line OAT whereas 3.4-6.9% provided subsequent injection initiation assistance. Per the primary weighted estimate (n = 1114 person-visits), participants currently on first-line OAT (versus no OAT) were 50% less likely, on average, to subsequently help someone initiate injecting (relative risk [RR]=0.50, 95% CI=0.23-1.11). First-line OAT was associated with reduced risk of subsequent injection initiation assistance provision in participants who, at baseline, injected opioids less than daily (RR=0.15, 95% CI=0.05-0.44) but not in those who injected opioids daily (RR=0.86, 95% CI=0.35-2.11). Conclusions: First-line OAT seemingly reduces the short-term likelihood that people who inject drugs facilitate first injections. However, the extent of this potential effect remains uncertain due to imprecise estimation and observed heterogeneity by baseline opioid injecting frequency.

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. Binary logistic regression was used to analyze the association between cannabis use to manage opioid cravings and self-reported changes in unregulated opioid use. RESULTS: A total of 205 people who use cannabis and opioids were enrolled in the present study from December 2019 to November 2021. Cannabis use to manage opioid cravings was reported by 118 (57.6%) participants. In the multivariable analysis, cannabis use to manage opioid cravings (adjusted Odds Ratio [aOR] = 2.13, 95% confidence interval [CI]: 1.07, 4.27) was significantly associated with self-reported reductions in opioid use. In the sub-analyses of pain, cannabis use to manage opioid cravings was only associated with self-assessed reductions in opioid use among people living with moderate to severe pain (aOR = 4.44, 95% CI: 1.52, 12.97). In the sub-analyses of males and females, cannabis use to manage opioid cravings was only associated with self-assessed reductions in opioid use among females (aOR = 8.19, 95% CI: 1.20, 55.81). CONCLUSIONS: These findings indicate that cannabis use to manage opioid cravings is a prevalent motivation for cannabis use among PWUO and is associated with self-assessed reductions in opioid use during periods of cannabis use. Increasing the accessibility of cannabis products for therapeutic use may be a useful supplementary strategy to mitigate exposure to unregulated opioids and associated harm during the ongoing drug toxicity crisis.

Associations between Drug Use and Sexual Risk Behaviours among Men Who Have Sex with Men in Japan: Results from the Cross-Sectional LASH Study.

This study assessed drug use patterns among men who have sex with men (MSM) in Japan, and evaluated their potential associations with sexual risk behaviours. Between September and October 2016, study subjects were recruited through a cross-sectional survey (LASH: Love Life and Sexual Health) using a geosocial networking application for MSM. Of the participants, 25.4% (1756/6921) reported ever having used drugs, and 11.3% (780/6921) reported having done so in the past six months. Those who used drugs were more likely to have greater knowledge of HIV/sexually transmitted infections (STIs). Drug use in the past six months was independently associated with each of the following sexual risk behaviours in the same period: (i) six or more sexual partners (adjusted odds ratio [aOR] = 2.70, 95% confidence interval [CI]: 2.30-3.17); (ii) condomless anal intercourse (aOR = 2.88, 95% CI: 2.43-3.42); (iii) group sex (aOR = 2.60, 95% CI: 2.22-3.05); and (iv) sex work (aOR = 2.30, 95% CI: 1.67-3.16). These results suggest that MSM in Japan who use drugs are more likely to report sexual risk behaviours, while also having greater knowledge of HIV/STIs. Supporting MSM to minimise the harm from drug use may be helpful in reducing HIV transmission among this priority population.

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.

Substance use and other factors associated with COVID-19 vaccine uptake among people at risk for or living with HIV: Findings from the C3PNO consortium.

Objective: We describe the prevalence of COVID-19 vaccine uptake, substance use, and other factors associated with vaccine hesitancy among participants from nine North American cohort studies following a diverse group of individuals at risk for or living with HIV. Methods: Between May 2021 and January 2022, participants completed a survey related to COVID-19 vaccination. Participants included those with and without substance use. Those responding as 'no' or 'undecided' to the question "Do you plan on getting the COVID-19 vaccine?" were categorized as vaccine hesitant. Differences between groups were evaluated using chi-square methods and multivariable log-binomial models were used to calculate prevalence ratios (PR) of COVID-19 vaccine hesitancy with separate models for each substance. Results: Among 1,696 participants, COVID-19 vaccination was deferred or declined by 16%. Vaccine hesitant participants were younger, with a greater proportion unstably housed (14.8% vs. 10.0%; p = 0.02), and not living with HIV (48.% vs. 36.6%; p <.01). Vaccine hesitant participants were also more likely to report cannabis (50.0% vs. 42.4%; p = 0.03), methamphetamine (14.0% vs. 8.2%; p <.01), or fentanyl use (5.5% vs. 2.8%; p = 0.03). Based on multivariable analyses methamphetamine or fentanyl use remained associated with COVID-19 vaccine hesitancy (Adjusted PR = 1.4; 95% CI 1.1-1.9 and Adjusted PR = 1.6; 95% CI 1.0-2.6, respectively). Conclusion: As new COVID-19 vaccines and booster schedules become necessary, people who use drugs (PWUD) may remain vaccine hesitant. Strategies to engage hesitant populations such as PWUD will need to be tailored to include special types of outreach such as integration with substance use programs such as safe injection sites or recovery programs.

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. METHODS: Using longitudinal data (2005-2018) from three prospective cohort studies including people who use drugs in Vancouver, Canada, we used repeated measures latent class analysis to identify different PSU classes among PWUO. Multivariable generalised estimating equations models weighted by the respective posterior membership probabilities were applied to identify covariates of membership in different PSU classes over time. RESULTS: Overall, 2627 PWUO (median age at baseline: 36 [quartile 1-3: 25-45]) were included between 2005 and 2018. We found five distinct PSU patterns, including low/infrequent probability of regular substance use (Class 1; 30%), primarily opioid and methamphetamine use (Class 2; 22%), primarily cannabis use (Class 3; 15%), primarily opioid and crack use (Class 4; 29%) and frequent PSU (Class 5; 4%). Membership in Class 2, 4 and 5 was positively associated with several behavioural and socio-structural adversities. DISCUSSION AND CONCLUSIONS: Findings of this longitudinal study suggest PSU is the norm among PWUO and highlights the heterogeneous characteristics of PWUO. The diversities within the population of PWUO need to be recognised in addiction care and treatment as well as optimising resource allocation in the response to the overdose crisis.

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. In sub-analysis we considered RMG opioids together with MOUD. RESULTS: We included 760 participants with presumed OUD. In the post-COVID-19 period, MOUD and slow-release oral morphine prevalence rates showed an estimated immediate increase in level (+7.6%, 95% CI: 0.6%, 14.6% and 1.8%, 95% CI: 0.3%, 3.3%, respectively), followed by a decline in the monthly trend (-0.8% per month, 95% CI: -1.4%, -0.2% and -0.2% per month, 95% CI: -0.4, -0.1, respectively). There were no significant changes in the prevalence trends of enrollment in methadone, buprenorphine/naloxone, or when RMG opioids were considered together with MOUD. CONCLUSIONS: Despite immediate improvements in MOUD enrollment in the post-COVID-19 period, this beneficial trend reversed over time. RMG opioids appeared to have provided additional benefits to sustain retention in OUD care.

Characterizing changes in drug use behaviour following supply shortages of 5-MeO-DIPT, alkyl nitrites and new psychoactive substances among men living with HIV in Japan.

BACKGROUND: Since 2005, Japan has incrementally banned a range of new psychoactive substances (NPS), including 5-MeO-DIPT (5MO; foxy) and alkyl nitrites (AN; rush, poppers) that have commonly been used among men who have sex with men (MSM). After the largest ban in 2014, these drugs were reported to have disappeared from the domestic market. Given that 5MO/AN/NPS use has been prevalent among men living with HIV in Japan, a population largely comprised of MSM, we sought to characterize changes in their drug use behavior following the supply shortages. METHODS: Using data from two waves of a nationwide survey of people living with HIV in Japan in 2013 and 2019-20 (n = 1042), we employed multivariable modified Poisson regression to identify correlates of self-reported reactions to the 5MO/AN/NPS shortages and changes in drug use behavior in 2019-20 vs. 2013. RESULTS: Among 391 men (96.7% MSM) surveyed in 2019-20, following the supply shortages, 234 (59.8%) stopped using 5MO/AN/NPS, 52 (13.3%) retained access to the supply, and 117 (29.9%) used substitute drugs: most commonly, methamphetamine (60.7%). Individuals who used substitutes were more likely to report unprotected sex (adjusted relative risk [ARR]=1.67; 95% confidence interval [CI]: 1.13-2.47) as well as low (ARR=2.35; 95% CI: 1.46-3.79) and lower middle (vs. upper middle to high) socioeconomic status (ARR=1.55; 95% CI: 1.00-2.41). The prevalence of past-year methamphetamine use (ARR=1.93; 95% CI: 1.11-3.35) and self-reported uncontrollable drug use (ARR=1.62; 95% CI: 1.07-2.53) were significantly higher in 2019-20 compared to 2013. CONCLUSION: Following the supply shortages, approximately one-fifth of our participants used methamphetamine as a substitute for 5MO/AN/NPS. Methamphetamine use and perceived uncontrollable drug use also appeared to have increased at the population level after the supply shortages. These findings suggest a potentially harmful substance displacement effect of the aggressive ban. Harm reduction interventions are needed in this population.