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.

Determinants of psychological distress during the COVID-19 pandemic among people who use drugs in Montreal, Canada.

INTRODUCTION: Limited data exists on psychological impacts of the COVID-19 pandemic among people who use drugs (PWUD). This study aimed to determine the prevalence and correlates of severe psychological distress (PD) among PWUD in Montreal around the beginning of the pandemic. METHODS: We conducted a rapid assessment study from May to December 2020 among PWUD recruited via a community-based cohort of people who inject drugs in Montreal (Hepatitis C cohort [HEPCO], N = 128) and community organisations (N = 98). We analysed self-reported data on changes in drug use behaviours and social determinants since the declaration of COVID-19 as a public health emergency, and assessed past-month PD using the Kessler K6 scale. Multivariable logistic regression was conducted to examine correlates of PD distress (score ≥13). RESULTS: Of 226 survey participants, a quarter (n = 56) were screened positive for severe PD. In multivariable analyses, age (1-year increment) (adjusted odds ratio = 0.94, 95% confidence interval [0.90, 0.98]) and a decrease in non-injection drug use versus no change (0.26 [0.07, 0.92]) were protective against severe PD, while positive associations were found for any alcohol use in the past 6 months (3.73 [1.42, 9.78]), increased food insecurity (2.88 [1.19, 6.93]) and both moving around between neighbourhoods more (8.71 [2.63, 28.88]) and less (3.03 [1.18, 7.74]) often compared to no change. DISCUSSION AND CONCLUSIONS: This study documented a high prevalence of severe PD among PWUD during the COVID-19 pandemic compared with pre-COVID-19 data. Social determinants such as food insecurity and mobility issues, alongside demographic and substance use-related factors, were linked to distress. Evidence-based risk mitigation strategies for this population could reduce negative consequences in future pandemics or disruptions.

Sex and gender differences in hepatitis C virus risk, prevention, and cascade of care in people who inject drugs: systematic review and meta-analysis.

Background: People who inject drugs (PWID) are a priority population in HCV elimination programming. Overcoming sex and gender disparities in HCV risk, prevention, and the cascade of care is likely to be important to achieving this goal, but these have not yet been comprehensively reviewed. Methods: Systematic review and meta-analysis. We searched Pubmed, EMBASE and the Cochrane Database of Systematic Reviews 1 January 2012-22 January 2024 for studies of any design reporting sex or gender differences among PWID in at least one of: sharing of needles and/or syringes, incarceration history, injection while incarcerated, participation in opioid agonist treatment or needle and syringe programs, HCV testing, spontaneous HCV clearance, direct-acting antiviral (DAA) treatment initiation or completion, and sustained virological response (SVR). Assessment of study quality was based on selected aspects of study design. Additional data were requested from study authors. Data were extracted in duplicate and meta-analysed using random effects models. PROSPERO registration CRD42022342806. Findings: 9533 studies were identified and 92 studies were included. Compared to men, women were at greater risk for receptive needle and syringe sharing (past 6-12 months: risk ratio (RR) 1.12; 95% confidence interval (CI) 1.01-1.23; <6 months: RR 1.38; 95% CI 1.09-1.76), less likely to be incarcerated (lifetime RR 0.64; 95% CI 0.57-0.73) more likely to be tested for HCV infection (lifetime RR 1.07; 95% CI 1.01, 1.14), more likely to spontaneously clear infection (RR1.58; 95% CI 1.40-1.79), less likely to initiate DAA treatment (0.84; 95% CI 0.78-0.90), and more likely to attain SVR after completing DAA treatment (RR 1.02; 95% CI 1.01-1.04). Interpretation: There are important differences in HCV risk and cascade of care indicators among people who inject drugs that may impact the effectiveness of prevention and treatment programming. Developing and assessing the effectiveness of gender-specific and gender-responsive HCV interventions should be a priority in elimination programming. Funding: Réseau SIDA-MI du Québec.

High COVID-19 vaccine uptake following initial hesitancy among people in Australia who inject drugs.

BACKGROUND: Previous studies have reported high COVID-19 vaccine hesitancy among people who inject drugs. We aimed to examine COVID-19 vaccine coverage, motivations and barriers to vaccination, and factors associated with uptake among this population in Australia, 1.5 years after vaccine rollout commenced. METHODS: In June-July 2022, 868 people (66.0 % male, mean age 45.6 years) who regularly inject drugs and reside in an Australian capital city reported the number of COVID-19 vaccine doses they had received and their primary motivation (if vaccinated) or barrier (if unvaccinated) to receive the vaccine. We compared vaccine uptake to Australian population estimates and used logistic regression to identify factors associated with ≥ 2 dose and ≥ 3 dose uptake. RESULTS: Overall, 84.1 % (n = 730) had received at least one COVID-19 vaccine dose, 79.6 % (n = 691) had received ≥ 2 doses, and 46.1 % (n = 400) had received ≥ 3 doses. Participants were less likely to be vaccinated than the Australian general population (prevalence ratio: 0.82, 95 % confidence interval [CI]: 0.76-0.88). Key motivations to receive the vaccine were to protect oneself or others from COVID-19, while barriers pertained to vaccine or government distrust. Opioid agonist treatment (adjusted odds ratio [aOR]: 2.49, 95 % CI: 1.44-4.42), current seasonal influenza vaccine uptake (aOR: 6.76, 95 % CI: 3.18-16.75), and stable housing (aOR: 1.58, 95 % CI: 1.02-2.80) were associated with receipt of at least two vaccine doses. Participants aged ≥ 40 years (versus < 40 years; aOR: 1.66, 95 % CI: 1.10-2.53) or who reported a chronic health condition (aOR: 1.71, 95 % CI: 1.18-2.47) had higher odds of receiving at least three vaccine doses. CONCLUSION: We observed higher COVID-19 vaccine uptake than expected given previous studies of vaccine acceptability among people who inject drugs. However, it was lower than the general population. People who inject drugs and reside in unstable housing are a subpopulation that require support to increase vaccine uptake.

Associations Between Supported Accommodation and Health and Re-offending Outcomes: a Retrospective Data Linkage Study.

Following release from prison, housing and health issues form a complex and mutually reinforcing dynamic, increasing reincarceration risk. Supported accommodation aims to mitigate these post-release challenges. We describe the impact of attending Rainbow Lodge (RL), a post-release supported accommodation service for men in Sydney, Australia, on criminal justice and emergency health outcomes. Our retrospective cohort study using linked administrative data includes 415 individuals referred to RL between January 2015 and October 2020. Outcomes of interest were rates of criminal charges, emergency department (ED) presentations and ambulance attendance; and time to first reincarceration, criminal charge, ED presentation and ambulance attendance. The exposure of interest was attending RL; covariates included demographic characteristics, release year and prior criminal justice and emergency health contact. Those who attended RL (n = 170, 41%) more commonly identified as Aboriginal or Torres Strait Islander (52% vs 41%; p = 0.025). There was strong evidence that attending RL reduced the incidence criminal charges (adjusted rate ratio [ARR] = 0.56; 95% confidence interval [CI] 0.340.86; p = 0.009). Absolute rates indicate a weak protective effect of RL attendance on ED presentation and ambulance attendance; however, adjusted analyses indicated no evidence of an association between attending RL and rates of ED presentations (ARR = 0.88; 95% CI = 0.65-1.21), or ambulance attendance (ARR = 0.82; 95% CI = 0.57-1.18). There was no evidence of an association between attending RL and time to first reincarceration, charge, ED presentation or ambulance attendance. Greater detail about reasons for emergency health service contact and other self-report outcome measures may better inform how supported accommodation is meeting its intended aims.

Prescription opioid use among people with opioid dependence and concurrent benzodiazepine and gabapentinoid exposure: An analysis of overdose and all-cause mortality.

BACKGROUND: Studies investigating mortality risk associated with use of opioid analgesics, benzodiazepines, gabapentinoids, and opioid agonist treatment (OAT) among people with opioid dependence (PWOD) are lacking. This study addresses this gap using a cohort of 37,994 PWOD initiating opioid analgesics between July 2003 and July 2018 in New South Wales, Australia. METHODS: Linked administrative records provided data on dispensings, sociodemographics, clinical characteristics, OAT, and mortality. Cox proportional hazards models assessed associations between time-varying measures of individual and concurrent medicine use and OAT with all-cause mortality, accidental opioid overdose, non-drug induced accidents, and non-drug-induced suicide. Opioid analgesic dose effects, expressed as oral morphine equivalents (OMEs) per day, were also examined. OUTCOMES: During the study period, 3167 individuals died. Compared with no use, all medicines of interest were associated with increased accidental opioid overdose risk; hazard ratios (HR) ranged from 1.33 (95 % CI: 1.05-1.68) for opioid analgesic use to 6.10 (95 % CI: 4.11-9.06) for opioid analgesic, benzodiazepine and gabapentinoid use. Benzodiazepine use was associated with increased non-drug-induced accidents and non-drug-induced suicides. For all-cause mortality, all combinations of benzodiazepines and gabapentinoids with opioid analgesics were associated with increased risk (aHRs ranged from 1.35 to 2.73). For most medicines/medicine combinations, all-cause mortality risk was reduced when in OAT compared to out of OAT. Higher opioid analgesic doses were associated with increased all-cause mortality (e.g., 90-199 mg vs 1-49 mg OME per day: HR 1.90 [95 % CI: 1.52-2.40]). INTERPRETATION: The increased mortality risk associated with benzodiazepines and gabapentinoids among PWOD appear to be reduced when engaged in OAT. A greater focus on encouraging OAT engagement, providing overdose prevention education, and access and coverage of overdose antidotes is necessary to minimise the unintended consequences of medicines use in this population.

Modeling as Visioning: Exploring the Impact of Criminal Justice Reform on Health of Populations with Substance Use Disorders.

In the context of historic reckoning with the role of the criminal-legal system as a structural driver of health harms, there is mounting evidence that punitive drug policies have failed to prevent problematic drug use while fueling societal harms. In this explainer article, we discuss how simulation modeling provides a methodological framework to explore the potential outcomes (beneficial and harmful) of various drug policy alternatives, from incremental to radical. We discuss potential simulation modeling opportunities while calling for a more active role of simulation modeling in visioning and operationalizing transformative change. Highlights: This article discusses opportunities for simulation modeling in projecting health and economic impacts (beneficial and harmful) of drug-related criminal justice reforms.We call on modelers to explore radical interventions to reduce drug-related harm and model grand alternative futures in addition to more probable scenarios, with a goal of opening up policy discourse to these options.

Gender, sexual orientation identity, and initiation of amphetamine injecting among people who inject drugs: Examination of an expanding drug era in Montreal, Canada, 2011-19.

BACKGROUND: Amphetamine injection is expanding in North America and has been associated with male homosexuality among people who inject drugs (PWID). Applying subcultural evolution theory, we examined overall and gender-stratified trends in amphetamine injection and assessed sexual orientation as a gender-specific predictor of initiation among PWID in Montreal, Canada. METHODS: Data were from HEPCO, an open prospective cohort of PWID. Gender and sexual orientation were self-identified at enrolment. Interviewer-administered questionnaires at three-monthly (HCV RNA-negative participants) or yearly (RNA-positive) intervals captured past three-month amphetamine injection and covariates. Annual prevalence and linear trends in amphetamine injection were estimated using GEE. Incidence was computed among naïve individuals and hazard ratios for initiation estimated using gender-stratified, time-varying Cox regression models. RESULTS: 803 participants contributed 8096 observations between March 2011 and December 2019. Annual prevalence of amphetamine injecting increased from 3.25% [95%CI: 2.06-4.43%] to 12.7% [9.50-16.0] (trend p<0.001). Bivariate Cox regression models suggested similar and divergent predictors of initiation by gender. Incidence was 3.27 per 100 person-years [95%CI: 2.51-4.18] among heterosexual men, 7.18 [3.50-13.2] among gay/bisexual men, 1.93 [0.78-4.02] among heterosexual women and 5.30 [1.69-12.8] among gay/bisexual women. Among men, gay/bisexual identity doubled risk of initiation after adjusting for age, ethnicity, calendar year (aHR 2.16 [1.07-4.36]) and additional covariates (2.56 [1.24-5.30]). Among women, evidence for an association with gay/bisexual identity was inconclusive (aHR 2.63 [0.62-11.2]) and sample size precluded further adjustment CONCLUSIONS: Prevalence of amphetamine injection among PWID increased four-fold from 2011 to 2019, with elevated risk of initiation in gay and bisexual men.

Five-Year Trajectories of Prescription Opioid Use.

Importance: There are known risks of using opioids for extended periods. However, less is known about the long-term trajectories of opioid use following initiation. Objective: To identify 5-year trajectories of prescription opioid use, and to examine the characteristics of each trajectory group. Design, Setting, and Participants: This population-based cohort study conducted in New South Wales, Australia, linked national pharmaceutical claims data to 10 national and state data sets to determine sociodemographic characteristics, clinical characteristics, drug use, and health services use. The cohort included adult residents (aged ≥18 years) of New South Wales who initiated a prescription opioid between July 1, 2003, and December 31, 2018. Statistical analyses were conducted from February to September 2022. Exposure: Dispensing of a prescription opioid, with no evidence of opioid dispensing in the preceding 365 days, identified from pharmaceutical claims data. Main Outcomes and Measures: The main outcome was the trajectories of monthly opioid use over 60 months from opioid initiation. Group-based trajectory modeling was used to classify these trajectories. Linked health care data sets were used to examine characteristics of individuals in different trajectory groups. Results: Among 3 474 490 individuals who initiated a prescription opioid (1 831 230 females [52.7%]; mean [SD] age, 49.7 [19.3] years), 5 trajectories of long-term opioid use were identified: very low use (75.4%), low use (16.6%), moderate decreasing to low use (2.6%), low increasing to moderate use (2.6%), and sustained use (2.8%). Compared with individuals in the very low use trajectory group, those in the sustained use trajectory group were older (age ≥65 years: 22.0% vs 58.4%); had more comorbidities, including cancer (4.1% vs 22.2%); had increased health services contact, including hospital admissions (36.9% vs 51.6%); had higher use of psychotropic (16.4% vs 42.4%) and other analgesic drugs (22.9% vs 47.3%) prior to opioid initiation, and were initiated on stronger opioids (20.0% vs 50.2%). Conclusions and relevance: Results of this cohort study suggest that most individuals commencing treatment with prescription opioids had relatively low and time-limited exposure to opioids over a 5-year period. The small proportion of individuals with sustained or increasing use was older with more comorbidities and use of psychotropic and other analgesic drugs, likely reflecting a higher prevalence of pain and treatment needs in these individuals.

The impact of supported accommodation on health and criminal justice outcomes of people released from prison: a systematic literature review.

BACKGROUND: Supported accommodation intends to address challenges arising following release from prison; however, impact of services, and of specific service components, is unclear. We describe key characteristics of supported accommodation, including program components and outcomes/impact; and distil best-evidence components. METHODS: We conducted a systematic review, searching relevant databases in November 2022. Data were synthesised via effect direction plots according to the Synthesis Without Meta-analysis guidelines. We assessed study quality using the McGill Mixed Methods Appraisal Tool, and certainty in evidence using the GRADE framework. RESULTS: Twenty-eight studies were included; predominantly cross-sectional. Program components which address life skills, vocational training, AOD use, and mental health appear to positively impact criminal justice outcomes. Criminal justice outcomes were the most commonly reported, and while we identified a reduction in parole revocations and reincarceration, outcomes were otherwise mixed. Variable design, often lacking rigour, and inconsistent outcome reporting limited assessment of these outcomes, and subsequently certainty in findings was low. CONCLUSION: Post-release supported accommodation may reduce parole revocations and reincarceration. Despite limitations in the literature, the findings presented herein represent current best evidence. Future studies should clearly define program components and measure their impact; use analyses which reflect the high risk of adverse outcomes, such as time-to-event analyses; and consider outcomes which reflect the range of challenges faced by people leaving prison. REGISTRATION: PROSPERO registration CRD42020189821.

Prevalence of opioid dependence in New South Wales, Australia, 2014-16: Indirect estimation from multiple data sources using a Bayesian approach.

AIMS: To estimate the prevalence of, and number of unobserved people with opioid dependence by sex and age group in New South Wales (NSW), Australia. DESIGN: We applied a Bayesian statistical modelling approach to opioid agonist treatment records linked to adverse event rate data. We estimated prevalence from three types of adverse event separately: opioid mortality, opioid-poisoning hospitalizations and opioid-related charges. We extended the model and produced prevalence estimates from a 'multi-source' model based on all three types of adverse event data. SETTING, PARTICIPANTS AND MEASUREMENTS: This study was conducted in NSW, Australia, 2014-16 using data from the Opioid Agonist Treatment and Safety (OATS) study, which included all people who had received treatment for opioid dependence in NSW. Aggregate data were obtained on numbers of adverse events in NSW. Rates of each adverse event type within the OATS cohort were modelled. Population data were provided by State and Commonwealth agencies. FINDINGS: Prevalence of opioid dependence among those aged 15-64 years in 2016 was estimated to be 0.96% (95% credible interval [CrI] = 0.82%, 1.12%) from the mortality model, 0.75% (95% CrI = 0.70%, 0.83%) from hospitalizations, 0.95% (95% CrI = 0.90%, 0.99%) from charges and 0.92% (95% CrI = 0.88%, 0.96%) from the multi-source model. Of the estimated 46 460 (95% CrI = 44 680, 48 410) people with opioid dependence in 2016 from the multi-source model, approximately one-third (16 750, 95% CrI = 14 960, 18 690) had no record of opioid agonist treatment within the last 4 years. From the multi-source model, prevalence in 2016 was estimated to be 1.24% (95% CrI = 1.18%, 1.31%) in men aged 15-44, 1.22% (95% CrI = 1.14%, 1.31%) in men 45-64, 0.63% (95% CrI = 0.59%, 0.68%) in women aged 15-44 and 0.56% (95% CrI = 0.50%, 0.63%) in women aged 45-64. CONCLUSIONS: A Bayesian statistical approach to estimate prevalence from multiple adverse event types simultaneously calculates that the estimated prevalence of opioid dependence in NSW, Australia in 2016 was 0.92%, higher than previous estimates.

Cohort profile: POPPY II - a population-based cohort examining the patterns and outcomes of prescription opioid use in New South Wales, Australia.

PURPOSE: The POPPY II cohort is an Australian state-based cohort linking data for a population of individuals prescribed opioid medicines, constructed to allow a robust examination of the long-term patterns and outcomes of prescription opioid use. PARTICIPANTS: The cohort includes 3 569 433 adult New South Wales residents who initiated a subsidised prescription opioid medicine between 2003 and 2018, identified through pharmacy dispensing data (Australian Pharmaceutical Benefits Scheme) and linked to 10 national and state datasets and registries including rich sociodemographic and medical services data. FINDINGS TO DATE: Of the 3.57 million individuals included in the cohort, 52.7% were female and 1 in 4 people were aged ≥65 years at the time of cohort entry. Approximately 6% had evidence of cancer in the year prior to cohort entry. In the 3 months prior to cohort entry, 26.9% used a non-opioid analgesic and 20.5% used a psychotropic medicine. Overall, 1 in 5 individuals were initiated on a strong opioid (20.9%). The most commonly initiated opioid was paracetamol/codeine (61.3%), followed by oxycodone (16.3%). FUTURE PLANS: The POPPY II cohort will be updated periodically, both extending the follow-up duration of the existing cohort, and including new individuals initiating opioids. The POPPY II cohort will allow a range of aspects of opioid utilisation to be studied, including long-term trajectories of opioid use, development of a data-informed method to assess time-varying opioid exposure, and a range of outcomes including mortality, transition to opioid dependence, suicide and falls. The duration of the study period will allow examination of population-level impacts of changes to opioid monitoring and access, while the size of the cohort will also allow examination of important subpopulations such as people with cancer, musculoskeletal conditions or opioid use disorder.

All-cause and cause-specific mortality in individuals with an alcohol-related emergency or hospital inpatient presentation: A retrospective data linkage cohort study.

BACKGROUND AND AIMS: Alcohol consumption is a leading risk factor for premature mortality globally, but there are limited studies of broader cohorts of people presenting with alcohol-related problems outside of alcohol treatment services. We used linked health administrative data to estimate all-cause and cause-specific mortality among individuals who had an alcohol-related hospital inpatient or emergency department presentation. DESIGN: Observational study using data from the Data linkage Alcohol Cohort Study (DACS), a state-wide retrospective cohort of individuals with an alcohol-related hospital inpatient or emergency department presentation. SETTING: Hospital inpatient or emergency department presentation in New South Wales, Australia, between 2005 and 2014. PARTICIPANTS: Participants comprised 188 770 individuals aged 12 and above, 66% males, median age 39 years at index presentation. MEASUREMENTS: All-cause mortality was estimated up to 2015 and cause-specific mortality (by those attributable to alcohol and by specific cause of death groups) up to 2013 due to data availability. Age-specific and age-sex-specific crude mortality rates (CMRs) were estimated, and standardized mortality ratios (SMRs) were calculated using sex and age-specific deaths rates from the NSW population. FINDINGS: There were 188 770 individuals in the cohort (1 079 249 person-years of observation); 27 855 deaths were recorded (14.8% of the cohort), with a CMR of 25.8 [95% confidence interval (CI) = 25.5, 26.1] per 1000 person-years and SMR of 6.2 (95% CI = 5.4, 7.2). Mortality in the cohort was consistently higher than the general population in all adult age groups and in both sexes. The greatest excess mortality was from mental and behavioural disorders due to alcohol use (SMR = 46.7, 95% CI = 41.4, 52.7), liver cirrhosis (SMR = 39.0, 95% CI = 35.5, 42.9), viral hepatitis (SMR = 29.4, 95% CI = 24.6, 35.2), pancreatic diseases (SMR = 23.8, 95% CI = 17.9, 31.5) and liver cancer (SMR = 18.3, 95% CI = 14.8, 22.5). There were distinct differences between the sexes in causes of excess mortality (all causes fully attributable to alcohol female versus male risk ratio = 2.5 (95% CI = 2.0, 3.1). CONCLUSIONS: In New South Wales, Australia, people who came in contact with an emergency department or hospital for an alcohol-related presentation between 2005 and 2014 were at higher risk of mortality than the general New South Wales population during the same period.

Does opioid agonist treatment reduce overdose mortality risk in people who are older or have physical comorbidities? Cohort study using linked administrative health data in New South Wales, Australia, 2002-17.

AIMS: To quantify the association between opioid agonist treatment (OAT) and overdose death by age group; test the hypothesis that across different age groups, opioid overdose mortality is lowest during OAT with buprenorphine compared with time out of treatment or OAT with methadone; and test associations between OAT and opioid overdose mortality in the presence of chronic circulatory, respiratory, liver and kidney diseases. DESIGN: Retrospective observational cohort study using linked administrative data. SETTING: New South Wales, Australia. PARTICIPANTS: A total of 37 764 people prescribed OAT, 1 August 2002 and 31 December 2017. MEASUREMENTS: OAT exposure, opioid overdose mortality and key confounders were measured using linked population data sets on OAT entry and exit, hospitalization, mental health care, incarceration and mortality. ICD-10 codes were used to define opioid overdose mortality and chronic disease groups of interest. FINDINGS: Relative to time out of treatment, time in OAT was associated with a lower risk of opioid overdose death across all age groups and chronic diseases. Among people aged 50 years and older, there was weak evidence that buprenorphine may be associated with greater protection against opioid overdose death than methadone [generalized estimating equation (GEE) adjusted incident rate ratio (aIRR) = 0.47; 95% confidence interval (CI) = 0.21, 1.02; marginal structural models (MSM) aIRR = 0.49; 95% CI = 0.17, 1.41]. Buprenorphine was associated with greater protection against overdose death than methadone for clients with circulatory (MSM aIRR = 0.27; 95% CI = 0.11, 0.67) or respiratory (MSM aIRR = 0.26; 95% CI = 0.07, 0.94) diseases, but not liver (MSM aIRR = 0.59; 95% CI = 0.14, 2.43) or kidney (MSM aIRR = 1.16; 95% CI = 0.31, 4.36) diseases. CONCLUSIONS: Opioid agonist treatment (OAT) appears to reduce mortality risk in people with opioid use disorder who are older or who have physical comorbidities. Opioid overdose mortality during OAT with buprenorphine appears to be lower and reduced in clients with circulatory and respiratory diseases compared with OAT with methadone.

HCV treatment initiation in the era of universal direct acting antiviral coverage - Improvements in access and persistent barriers.

BACKGROUND: Barriers to HCV treatment initiation persisted after the introduction of direct-acting antivirals (DAAs) in Canada among people who inject drugs (PWID); whether DAA universal coverage lifted these barriers remain unknown. We assessed the evolution of HCV treatment initiation and associated factors among PWID in Montreal, Canada, comparing eras of IFN-based regimens (2011-2013), of DAA restricted access (2014-02/2018), and universal coverage (03/2018-03/2020). METHODS: We included chronically HCV-infected participants followed in a community-based PWID cohort in Montreal, Canada between 2011 and 03/2020 and collected data at 3-month intervals. Time-updated Cox regressions were conducted to examine 9 variables of interest associated with treatment initiation overall and for each of the three eras. RESULTS: Of 276 participants, 126 initiated treatment during follow-up. Yearly initiation increased from 3% in 2011 to 19% in 2016, and 54% in 2018. PWID aged >40 (vs. ≤40) were twice as likely to initiate treatment in 2014-02/2018 (HR: 2.02 95%CI: [1.24-3.28]) but not in other periods (2011-2013: 0.55 [0.25-1.22]; 03/2018-03/2020: 1.14 [0.59-2.22])). Odds of initiation were lower for men than women in all periods, with women three times more likely to be treated under universal coverage (0.30 [0.11-0.77] vs 2011-2013: 0.67 [0.25-1.78] and 2014-02/2018: 0.75 [0.42-1.35]). Recent incarceration was negatively associated with initiation throughout all periods (2011-2013: 0.57 [0.13-2.43]; 2014-03/2018: 0.39 [0.17-0.91]; 03/2018-03/2020: 0.25 [0.07-0.83]). Barriers associated with high injection frequency appear to have diminished since DAA introduction (2014-02/2018: 0.71 [0.42-1.20]; 03/2018-03/2020: 1.05 [0.52-2.11] vs. 2011-2013: 0.26 [0.08-0.88]). Contact with a primary care physician and engagement in opioid agonist therapy were positively associated with treatment initiation, though estimates were attenuated under universal coverage relative to previous eras. CONCLUSION: Treatment initiation rates have increased since the introduction of universal DAA coverage, though barriers such as incarceration persist.

Associations between the prevalence of chronic hepatitis B among people who inject drugs and country-level characteristics: An ecological analysis.

INTRODUCTION: Globally, hepatitis B virus (HBV) is a leading cause of liver disease. People who inject drugs (PWID) are at greater risk than the general population of contracting HBV. This risk could depend on societal factors in different countries. We investigated the associations between country-level chronic HBV prevalence in PWID with national indicators of development and prevalence of HIV and hepatitis C virus (HCV). METHODS: We used global systematic review data on chronic HBV prevalence (hepatitis B surface antigen-positive) among PWID and country-level sociodemographic characteristics from online databases. National random-effects meta-analysis estimates of HBV prevalence were the outcome in linear regression models testing for associations with country-level characteristics. RESULTS: The study included 131,710 PWID from 304 estimates in 55 countries: the pooled HBV prevalence among PWID in the countries analysed was 4.5% (95% CI 3.9-5.1), the highest regional pooled prevalence was in East and Southeast Asia (17.6% [13.3-22.3]), and the lowest was in Western Europe (1.7% [1.4-2.1]). In multivariable models, no indicators of development were associated with HBV prevalence, but there was evidence of positive associations between HBV prevalence in the general population and among PWID, and evidence of HIV and HCV prevalence in PWID being associated with HBV prevalence in PWID: multivariable coefficients 0.03 (95% CI 0.01-0.04); p < 0.001, and 0.01 (95% CI 0.00-0.03); p = 0.01, respectively. DISCUSSION AND CONCLUSIONS: HBV prevalence among PWID was associated with HIV and HCV prevalence among PWID and background HBV prevalence in the general population, highlighting the need for improving harm reduction in PWID and implementation of HBV vaccination, especially where HBV is endemic.

Association Between Markers of Vulnerability for Cannabis-Related Harms and Source of Supply: Secondary Analysis of a Representative Population Survey.

OBJECTIVE: In 2018, the sale of non-medical cannabis was authorized in the province of Quebec in Canada, within a public monopoly under the Société Québécoise du Cannabis (SQDC). The objective of this study was to offer a description of the cannabis-using population regarding the sources of cannabis supply and to explore whether at-risk individuals are purchasing cannabis at SQDC. METHOD: We used data from a cross-sectional, representative population survey (age >18 years, n = 1799), the Enquête Québécoise sur le Cannabis, which was completed between February and June 2019. Analyses involved adjusted binary logistic regressions, incorporating population weights, to assess 7 potential indicators of harm. RESULTS: The vulnerability profiles of SQDC consumers (47.8%) and those acquiring their cannabis elsewhere (52.2%) were similar in terms of frequency of cannabis use (adjusted odds ratio [aOR] = 0.46; 95% confidence interval [CI] = 0.12-1.67), motivation to use (aOR = 0.62; 95% CI = 0.16-2.46), concomitant consumption of other substances (aOR = 0.80; 95% CI = 0.14-4.75), cannabis-impaired driving behaviours (aOR = 0.93; 95% CI = 0.26-3.36), psychological distress (aOR = 0.99; 95% CI = 0.26-3.79), and problematic cannabis use (aOR = 0.46; 95% CI = 0.13-1.64). However, SQDC consumers were more likely to be aware of the cannabinoid content of the product purchased compared to those who acquired their cannabis from other sources (aOR = 4.12; 95% CI = 1.10-15.40). CONCLUSIONS: No association was detected between the source of cannabis supply and potential vulnerability indicators of cannabis-related harms, but SQDC consumers were more aware of the cannabinoid content of the products purchased. These results suggest that the regulated government supply in Quebec is reaching a substantial portion of those with potential high vulnerability to harm. Whether this knowledge translates into a reduction in the negative consequences related to consumption is still to be determined.