Search

Background and Aims: Although the Netherlands, Canada and Australia were early adopters of harm reduction for people who inject drugs (PWID), their respective HIV and hepatitis C (HCV) epidemics differ. We measured the pooled effect of needle and syringe program (NSP) and opioid agonist therapy (OAT) participation on HIV and HCV incidence in these settings. Design: For each cohort, we emulated the design and statistical analysis of a target trial using observational data. Setting and Participants: We included PWID at risk of HIV or HCV infection from the Amsterdam Cohort Studies (1985–2013), Vancouver Injection Drug Users Study (1997–2009) and Melbourne Injecting Drug User Cohort Study (SuperMIX) (2010–2021). Measurements: Separately for each infection and cohort (only HCV in SuperMIX), marginal structural models were used to compare the effect of comprehensive (on OAT and 100% NSP coverage or on OAT only if no recent injection drug use) versus no/partial NSP/OAT (no OAT and/or

Objective Retaining adolescents and young adults (AYA) in medications for opioid use disorder (MOUD), like methadone maintenance treatment (MMT), is critical to reducing toxic drug fatalities. This analysis sought to identify factors associated with MMT discontinuation among AYA. Method Data were derived from the At-Risk Youth Study, a prospective cohort study of street-involved AYA in Vancouver, Canada, between December 2005 and June 2018. Multivariable extended Cox regression identified factors associated with time to MMT discontinuation among AYA who recently initiated MMT. In subanalysis, multivariable extended Cox regression analysis identified factors associated with time to “actionable” MMT discontinuation, which could be addressed through policy changes. Results A total of 308 participants reported recent MMT during the study period. Participants were excluded if they reported MMT in the past 6 months at baseline and were retained in MMT ( n = 94, 30.5%); were missing MMT status data ( n = 43, 14.0%); or completed an MMT taper ( n = 11, 3.6%). Of the remaining 160 participants who initiated MMT over the study period, 102 (63.8%) discontinued MMT accounting for 119 unique discontinuation events. In multivariable extended Cox regression, MMT discontinuation was positively associated with recent weekly crystal methamphetamine use (adjusted hazard ratio [AHR] = 1.67, 95% confidence interval [CI]: 1.19 to 2.35), but negatively associated with age of first “hard” drug use (per year older) (AHR = 0.95, 95% CI: 0.90 to 1.00) and female sex (AHR = 0.66, 95% CI: 0.44 to 0.99). In subanalysis, recent weekly crystal methamphetamine use (AHR = 4.61, 95% CI: 1.78 to 11.9) and weekly heroin or fentanyl use (AHR = 3.37, 95% CI: 1.21 to 9.38) were positively associated with “actionable” MMT discontinuation, while older age (AHR = 0.87, 95% CI: 0.76 to 0.99) was negatively associated. Conclusions Efforts to revise MMT programming; provide access to a range of MOUD, harm reduction, and treatments; and explore coprescribing stimulants to AYA with concurrent stimulant use may improve treatment retention and reduce toxic drug fatalities.

Optimal dosing of opioid agonist therapy (OAT) is essential for treatment success. However, initiation and maintenance of OAT in hospital settings can be challenging given differing levels of opioid tolerance, withdrawal, and intoxication among patients.The objective of this study was to characterize the prevalence and factors associated with in-hospital patient perceived suboptimal OAT dosing among people who use illicit drugs (PWUD) in Vancouver, Canada.Data were derived from three prospective cohorts of PWUD in Vancouver, Canada. Bivariable and multivariable logistic regression models were used to examine factors associated with patient perceived suboptimal in-hospital OAT dose.273 study participants were prescribed OAT while in hospital: 83 (30.4%) participants perceived their OAT dose to be suboptimal. In a multivariable model, factors positively associated with a perceived suboptimal OAT dose included: homelessness (adjusted odds ratio [AOR] = 2.85; 95% CI: 1.53-5.28), daily stimulant use (AOR = 2.03; 95% CI: 1.14-3.63) and illicit drug use while in hospital (AOR = 2.33; 95% CI: 1.31-4.16).Almost one third of participants perceived receiving a suboptimal OAT dose while in hospital. These observed correlations indicate that a patient's perception of suboptimal OAT dosing in hospital may be more prevalent for patients who are homeless, report polysubstance use with stimulants and opioids and who obtain illicit drugs while hospitalized. While cautious prescribing of

A managed alcohol program (MAP) is a harm reduction strategy that provides regularly, witnessed alcohol to individuals with a severe alcohol use disorder. Although community MAPs have positive outcomes, applicability to hospital settings is unknown. This study describes a hospital-based MAP, characterizes its participants, and evaluates outcomes.A retrospective chart review of MAP participants was conducted at an academic hospital in Vancouver, Canada, between July 2016 and October 2017. Data included demographics, alcohol/substance use, alcohol withdrawal risk, and MAP indication. Outcomes after MAP initiation included the change in mean daily alcohol consumption and liver enzymes.Seventeen patients participated in 26 hospital admissions: 76% male, mean age of 54 years, daily consumption prehospitalization of a mean 14 alcohol standard drinks, 59% reported previous nonbeverage alcohol consumption, and 41% participated in a community MAP. Most participants were high risk for severe, complicated alcohol withdrawal and presented in moderate withdrawal. Continuation of community MAP was the most common indication for hospital-based MAP initiation (38%), followed by a history of leaving hospital against medical advice (35%) and hospital illicit alcohol use (15%). Hospital-based MAP resulted in a mean of 5 fewer alcohol standard drinks daily compared with preadmission (P = 0.002; 95% confidence interval, 2-8) and improvement in liver enzymes, with few adverse events.Participation in a hospital-based MAP may be an effective safe approach to reduce harms for some individuals with severe alcohol use disorder. Further study is needed to understand who benefits most from hospital-MAP and potential benefits/harms following hospital discharge.

Objectives: Driven by an increasingly toxic drug supply, drug toxicity deaths in the United States and Canada have risen to unprecedented levels during the COVID-19 pandemic. This study aimed to characterize the prevalence of and the factors associated with a perceived decline in the quality of drugs during the COVID-19 pandemic among community-recruited cohorts of PWUD in Vancouver, Canada. Methods: Data collection took place between July and November 2020. In adherence with COVID-19 safety protocols, questionnaires were administered by interviewers through remote means (e.g., phone or videoconference). Using multivariable logistic regression, we characterized the prevalence of and factors associated with a perceived decline in drug quality during the start of the COVID-19 pandemic in Vancouver, Canada. Results: Of the 738 individuals included in this analysis, 272 (36.9%) reported that the quality of drugs declined during the COVID-19 pandemic. In multivariable analysis, perceived decline in the quality of drugs was significantly associated with: recent non-fatal overdose (adjusted odds ratio [AOR]=2.01, 95% Confidence Interval [CI]: 1.29-3.15), at least weekly injection drug use (AOR=1.94, 95% CI: 1.40-2.71), at least weekly crack use (AOR=1.61, 95%CI: 1.10-2.36), and at least weekly crystal methamphetamine use (AOR=1.46, 95%CI: 1.03-2.08). Discussion: Over a third of PWUD perceived that the quality of drugs declined during the COVID-19 pandemic and these individuals were significantly more likely to report experiencing a recent non-fatal overdose, engaging in frequent injection drug and stimulant use. Study findings indicate the need for interventions to address the toxic drug supply, including providing a regulated supply.

Introduction and Aims: Illicitly-manufactured fentanyl continues to fuel the opioidoverdose crisis throughout the United States and Canada. However, little is known about factors associated with knowingly or unknowingly using fentanyl. Therefore, we sought to identify the prevalence and correlates of suspected/known and unknown exposure to fentanyl (excluding the prescribed one) among people who inject drugs (PWID), including associated overdose risks. Design and Methods: Data were derived from three prospective cohort studies of community-recruited people who use drugs in Vancouver, Canada in 2016–2017. Multivariable logistic regression was used to identify correlates of suspected/known exposure (i.e., urine drug screen positive [UDS+] and self-reporting past three-day exposure) and unknown exposure to fentanyl (i.e., UDS+ and self-reporting no past three day exposure), respectively. Results: Among 590 PWID, 296 (50.2%) tested positive for fentanyl. Of those, 143 (48.3%) had suspected/known and 153 (51.7%) had unknown exposure to fentanyl. In multivariable analyses, using supervised injection sites and possessing naloxone were associated with both suspected/known and unknown exposure (all p

Introduction Retention in opioid agonist therapy consistently has been linked with improved outcomes among people with opioid use disorder. However, less is known about the links between patterns of engagement in opioid agonist therapy over the long term and overdose risk. This study assesses the association of opioid agonist therapy retention trajectories with nonfatal overdose. Methods Data were drawn from 2 community-recruited prospective cohorts of people who use drugs in Vancouver, Canada. Latent class growth analysis was used to identify trajectories of opioid agonist therapy retention among people with opioid use disorder initiating therapy, and generalized estimating equations assessed the association of these trajectories with nonfatal overdose events after opioid agonist therapy initiation. Results Between 2005 and 2018, among 438 opioid agonist therapy initiators, 4 retention trajectories were identified: consistently high (35.6%), increasing (26.0%), consistently low (23.3%), and decreasing (15.1%) opioid agonist therapy engagement. During the study period, there were 371 nonfatal overdose events, with 179 (40.1%) participants reporting ≥1. In adjusted analysis, the consistently low (AOR=1.73, 95% CI=1.10, 2.71) and decreasing (AOR=1.87, 95% CI=1.18, 2.95) retention trajectories were positively associated with increased odds of nonfatal overdose compared with the consistently high opioid agonist therapy retention class. Conclusions Suboptimal trajectories of opioid agonist therapy retention were associated with an increased likelihood of nonfatal overdose. These findings suggest that reducing the barriers to sustained engagement in opioid agonist therapy will be critical to address North America's overdose epidemic.

BACKGROUND: To evaluate how an international one-year intensive research training program for addiction medicine physicians contributed to subsequent research involvement and productivity. METHODS: We prospectively compared addiction medicine physician fellows admitted to a one-year training program with non-admitted controls, using baseline questionnaire and peer-reviewed publication data. Participants’ publication activity was assessed from fellowship application date onwards using biomedical databases (e.g., PubMed, Embase). RESULTS: Between July 2014 and June 2020, which is six years of cohorts, 56 (39 women) physicians, both fellows (n = 25) and non-admitted applicants (n = 31), were observed and included in the study, contributing 261 person-years of observation. At baseline, in the fellows’ cohort: 76% of participants (19/25) reported past research involvement, 24% (6/25) had one or more advanced graduate degrees (e.g., MPH), and the median number of peer-reviewed, first author publications was one (Interquartile Range [IQR] = 0–2). At baseline, in the controls’ cohort: 84% of participants (26/31) reported past research involvement, 39% (12/31) had one or more advanced graduate degrees, and the median number of peer-reviewed, first author publications was zero. The physicians’ training included internal medicine (n = 8), family medicine (n = 33), psychiatry (n = 5) and others (n = 4). At follow up, there was a significant difference between fellows (n = 25) and controls (n = 31) in total number of publications (Rate Ratio [RR] = 13.09, 95% Confidence Interval [CI], 5.01 − 34.21, p < 0.001), as well as first author publications (RR = 5.59, 95% CI, 2.23 − 14.06, p < 0.001). CONCLUSION: In the six-year observation period, fellows’ productivity indicates undertaking this fellowship was associated with significant research outputs in comparison to controls, signaling successful training of addiction physicians to help recruit addiction medicine physicians to participate in addiction research.

OBJECTIVES Gaps in addiction medicine training are a reason for poor substance use care in North America. Hospital addiction medicine consult services (AMCS) provide critical medical services, including screening and treatment of substance use disorders. Although these programs often feature an educational component for medical learners, the impact of AMCS teaching on objective knowledge and career aspirations in addiction medicine has not been well described. METHODS The authors report findings from two sequential studies conducted at a large academic hospital in Vancouver, Canada. The first study assessed the impact of an AMCS clinical rotation on medical trainee addiction medicine objective knowledge using an online survey of 6 true/false questions before and after the rotation. The second study examined the impact of an AMCS rotation on career aspirations using 4 seven-point Likert-type questions. One-sample t tests on mean differences (MD) with Benjamini-Hochberg adjustment for multiple comparisons were employed for statistical analyses. RESULTS Between May 2017 and June 2018, knowledge scores were significantly higher postrotation (MD = 4.78, standard deviation [SD] = 19.5, P = 0.034) among 115 medical trainees. Between July 2018 and July 2019, aspirations to practice addiction medicine were significantly more favorable postrotation (MD = 3.48, SD = 3.15, P

BACKGROUND AND AIMS Income assistance is critical to the health and wellbeing of socio-economically marginalized people who use illicit drugs (PWUD). However, past literature paradoxically identifies unintended increases in drug-related harm coinciding with synchronized payments that may magnify signals for drug use. The scope of such harm has not been fully characterized among non-institutionalized populations. This study examined socio-demographic, health and drug use-related correlates of payment-coincident drug-related harm. DESIGN This observational study uses data from prospective community-based longitudinal cohorts of PWUD between December 2013 and May 2018. SETTING Vancouver, British Columbia, Canada. PARTICIPANTS A total of 1604 PWUD receiving monthly income assistance. Our sample included 586 (36.5%) women, 861 (53.7%) non-white participants and 685 (42.7%) people living with HIV. MEASUREMENTS The primary outcome was a self-reported composite measure of drug-related harm in the past 6 months coinciding with income assistance, including higher-frequency substance use, non-fatal overdose and service barriers or interruptions. Subanalyses disaggregated this outcome. FINDINGS Payment-coincident drug-related harm was reported among 77.7% of participants during the study period. In multivariable models, key correlates positively and significantly associated with payment-coincident harm included: street-based income generation [adjusted odds ratio (aOR) = 1.48, 95% confidence interval (CI) = 1.26-1.74, P

BACKGROUND: People who use injection drugs (PWID) experience high rates of HIV acquisition and, as a result of lower rates of optimal access and adherence to combination antiretroviral therapy (ART), experience worse HIV treatment outcomes compared to other key affected populations. However, the incidence and risk factors for the development of AIDS among HIV-positive PWID have not been completely described. METHODS: We used data from a community-recruited prospective cohort of HIV-positive PWID in Vancouver, Canada, a setting with universal no-cost ART and a comprehensive clinical monitoring registry. We used multivariable extended Cox models to identify factors associated with time to AIDS. RESULTS: Between 1996 and 2017, 396 participants, including 140 (35.4%) women, were followed for a median of 39.0 months (interquartile range: 16.6 - 76.2), among whom 165 (41.7%) developed AIDS. In a multivariable model, homelessness (Adjusted Hazard Ratio [AHR] = 1.76 (1.18-2.61) and injection drug use within the preceding six months (AHR = 1.74 (1.17-2.58) were independently associated with higher risk of developing AIDS. CONCLUSIONS: Despite widespread scale-up of programs to improve ART utilization, significant risk factors for development of AIDS remain among HIV-positive PWID in this setting.

The objective of this study was to identify migration patterns from an open illicit drug scene (the Downtown Eastside [DTES] neighborhood) and describe factors associated with these migration patterns. Data were derived from three cohorts of people who use illicit drugs in Vancouver, Canada. Defined using latent class growth analysis, we identified four distinct migration trajectory groups: 1) consistently living in the DTES (47.8%); 2) early migration out, with a median time of migrating out of DTES of 5.3 months (21.5%); 3) late migration out, with a median time of migrating out of DTES of 38.0 months (20.1%); and 4) frequent revisit back-and-forth to DTES (10.6%). In a multivariable model, compared to the “consistently living in the DTES” group, factors associated with the “frequent revisit” group included being enrolled in non-pharmacological addiction treatment and having an HCV-positive serostatus. Factors associated with the “early migration out” group included being enrolled in detoxification or in other non-pharmacological addiction treatment, later calendar year, being on income assistance, living in a single room occupancy hotel, and having an HCV-positive serostatus. These findings point to the need for appropriate distribution of services in order to meet the needs of this population.

To explore the clinical characteristics, genetic basis and clinical treatment of seven neonates with congenital nephrogenic diabetes insipidus (NDI).Clinical data of the patients were collected. High-throughput sequencing was carried out to detect potential variants. Sanger sequencing was used to verify the results.The patients were all males, with the age of onset being 10 to 21 days. All patients were admitted to the hospital for intermittent fever as the first symptom during the neonatal period. Additional symptoms had included polydipsia and polyuria. After the treatment, 5 patients had recovered, the remainders still had NDI symptoms and developmental retardation. Five children were found to harbor pathogenic variants of the AVPR2/AQP2 gene, which included one in-frame mutation of c.645_646insGCACCTACCCTGGGTATCGCC, two missense mutations of c.541CT and c.419CA, and two hemizygous deletions of the AVPR2/AQP2 gene. Among these, two were unreported previously. Cases 6 and 7 were a pair of twins. Both had carried homozygous missense variants of c.538GA of the AVPR2/AQP2 gene, which was known to be pathogenic.AVPR2/AQP2 is the main pathogenic gene for congenital NDI, for which two novel pathogenic variants have been discovered in this study. Above results have provided a basis for clinical diagnosis and genetic counseling for the affected pedigrees.

Objectives: High levels of morbidity and mortality associated with injection drug use continue to represent a significant public health challenge in many settings worldwide. Previous studies have shown an association between cannabis use and decreased risk of some drug-related harms. We sought to evaluate the association between high-intensity cannabis use and the frequency of injection drug use among people who inject drugs (PWID). Methods: The data for this analysis were collected from three prospective cohorts of PWID in Vancouver, Canada, between September 2005 and May 2018. Generalized linear mixed-effects models were used to analyze the association between daily cannabis use and the frequency of injecting illegal drugs (i.e., self-reported average number of injections per month). Results: Among the 2,619 active PWID, the frequency of injection drug use was significantly lower among people who use cannabis daily compared with people who use it less than daily (adjusted odds ratio [AOR]=0.84, 95% confidence interval [CI]: 0.73–0.95). Sub-analyses indicated that this effect was restricted to the frequency of illegal opioid injection (AOR=0.78, 95% CI: 0.68–0.90); the association between daily cannabis use and the frequency of illegal stimulant injection was not significant (AOR=1.08, 95% CI 0.93–1.25). Discussion: The findings from these prospective cohorts suggest that people who use cannabis daily were less likely to report daily injection of illegal drugs compared with people who use it less than daily. These results suggest the potential value of conducting experimental research to test whether controlled administration of cannabinoids impacts the frequency of illegal opioid injection among PWID.

OBJECTIVES: Methamphetamine use is rising globally and we have limited treatments for this. Subgroups within the diverse methamphetamine-using population may have distinct treatment needs. Among a community-recruited sample of people who use crystal methamphetamine, we aimed to identify subgroups and characterize their overdose risk and access to addiction care. METHODS: Data from prospective cohorts of people who use drugs in Vancouver, Canada from 2014 to 2018 were used to conduct a repeated measures latent class analysis among participants who used crystal methamphetamine. Multivariable generalized estimating equations models were fit to determine the associated factors. RESULTS: Among 824 eligible participants, a five-class model was identified as the best fit: (1) primary stimulant use (15.7%); (2) women engaged in sex work and opioid use (21.4%); (3) street income generation and opioid use (31.6%); (4) opioid agonist therapy (OAT) patients (22.3%); and (5) men who have sex with men (9.0%). In multivariable analyses, compared to the primary stimulant use group, non-fatal overdose was positively associated with street income generation (adjusted odds ratio [AOR] = 1.49, 95% confidence interval [95% CI]=1.30–1.71), sex work (AOR = 1.38, 95% CI=1.20–1.59) and OAT (AOR = 1.22, 95% CI=1.06–1.41) subgroups; engagement in non-OAT addiction care was negatively associated with street income generation (AOR = 0.81, 95% CI=0.68–0.97) and sex work (AOR = 0.78, 95% CI=0.63–0.98) subgroups. DISCUSSION: Socioeconomically marginalized subgroups with opioid and crystal methamphetamine co-use were at highest risk of non-fatal overdose and had poorer access to addiction care, highlighting the need for tailored interventions.

Background Settings throughout the United States and Canada are contending with high rates of drug-related overdose. This in turn has prompted efforts to more effectively engage people who use drugs (PWUD) in treatment and care. However, while co-morbid mental disorders are prevalent among PWUD and can undermine access to services, the impact of post-traumatic stress disorder (PTSD) on service access is not known. Therefore, we sought to assess whether PTSD is associated with difficulties accessing health and social services among PWUD in Vancouver, Canada. Methods Survey data was derived from two prospective cohorts of PWUD in Vancouver, Canada for the period of April 2017 to November 2018. PTSD was assessed using the PTSD Checklist for the DSM-V (PCL-5). Generalized estimating equations (GEE) was used to estimate the relationship between PTSD and self-reported inability to access health and social services, after adjustment for confounders. Results Among 810 participants included in our analysis, 316 (39.0%) participants qualified for a provisional PSTD diagnosis, and 117 (14.4%) reported difficulties accessing services. In a multivariable GEE analysis, a PTSD diagnosis (adjusted odds ratio = 1.69, 95% confidence interval: 1.12–2.55) was independently associated with difficulties accessing services. Conclusions We found high rates of PTSD and self-reported difficulties accessing services among PWUD in Vancouver, as well as a positive association between PTSD and difficulties with service access. These findings highlight the need for trauma-informed approaches to service delivery for PWUD, as well as enhanced provider training specific to PTSD.

BACKGROUND: People living with HIV who use illicit drugs continue to experience high rates of suboptimal treatment outcomes from antiretroviral therapy (ART). Although previous studies have identified important behavioural, social and structural barriers to ART adherence, the effects of patient-level factors have not been fully evaluated. Thus, we sought to investigate the prevalence and correlates of reporting ART was difficult to take among a cohort of illicit drug users in Vancouver, Canada. METHODS: We accessed data from the AIDS Care Cohort to evaluate Exposure to Survival Services (ACCESS), an ongoing prospective cohort of HIV-positive illicit drug users linked to comprehensive HIV clinical monitoring records. We used generalized linear mixed-effects modeling to identify factors longitudinally associated with periods in which individuals reported they found ART difficult to take. RESULTS: Between December 2005 and May 2014, 746 ART-exposed illicit drug users were recruited and contributed at least one study interview. Finding ART hard to take was reported by 209 (28.0%) participants at baseline, and 460 (61.7%) participants throughout the study period. Patients ingesting a greater daily pill count (Adjusted Odds Ratio [AOR] = 1.12 per pill, 95% Confidence Interval [CI]: 1.08–1.17) and experiencing barriers to healthcare (AOR = 1.64, 95% CI: 1.34–2.01) were more likely to report difficulty taking ART. Patients less likely to report satisfaction with their HIV physician (AOR = 0.76, 95% CI: 0.58–1.00) and achieve a non-detectable HIV viral load (AOR = 0.62, 95% CI: 0.51–0.74) were more likely to report finding ART hard to take. CONCLUSION: In this community-recruited cohort of ART-exposed illicit drug users, a substantial proportion reported they found HIV treatment hard to take, which was clearly linked to higher dissatisfaction with healthcare experiences and, most importantly, a lower likelihood of experiencing optimal virologic outcomes. Our findings reveal a number of opportunities to improve HIV treatment experiences and outcomes for people who use illicit drugs, including the use of treatment regimens with lower pill burdens, as well as reducing barriers to healthcare access.

People who use illicit drugs (PWUD) experience various adverse health outcomes leading to increased healthcare service utilization. PWUD are also a highly mobile population which poses challenges to healthcare delivery. The objective of this study was to identify migration patterns from the Downtown Eastside (DTES), an urban illicit drug scene in Vancouver and to estimate the impact of different migration patterns on two outcomes: a) emergency department (ED) visits and b) ED visits resulting in inpatient admission among PWUD.Three prospective cohorts of PWUD in Vancouver were linked with regional ED data. We defined the optimal number of trajectory groups that best represented distinct patterns of migration from Vancouver's DTES using a latent class growth analysis. Then, generalized estimating equations were used to estimate the effect of migration patterns on the two ED outcomes.Four distinct migration trajectory patterns were identified among the 1210 included participants: PWUD who consistently lived in the DTES, those who migrated out of DTES early, those who migrated out of DTES late, and those who frequently revisited the DTES. Participants who frequently revisited the DTES had higher odds of an ED visit (adjusted odds ratio = 1.62; 95% confidence interval: 1.28-2.06). There was no significant association between migration patterns and inpatient admission.We found that PWUD who frequently revisited the DTES were more likely to have utilized the ED, suggesting that there may be a subgroup of PWUD who are at increased risk of experiencing negative health outcomes.Supplemental data for this article is available online at 10.1080/10826084.2021.1958849.

Objectives. To evaluate the impact of frequent cannabis use on injection cessation and injection relapse among people who inject drugs (PWID). Methods. Three prospective cohorts of PWID from Vancouver, Canada, provided the data for these analyses. We used extended Cox regression analysis with time-updated covariates to analyze the association between cannabis use and injection cessation and injection relapse. Results. Between 2005 and 2018, at-least-daily cannabis use was associated with swifter rates of injection cessation (adjusted hazard ratio [AHR] = 1.16; 95% confidence interval [CI] = 1.03, 1.30). A subanalysis revealed that this association was only significant for opioid injection cessation (AHR = 1.26; 95% CI = 1.12, 1.41). At-least-daily cannabis use was not significantly associated with injection relapse (AHR = 1.08; 95% CI = 0.95, 1.23). Conclusions. We observed that at-least-daily cannabis use was associated with a 16% increase in the hazard rate of injection cessation, and this effect was restricted to the cessation of injection opioids. This finding is encouraging given the uncertainty surrounding the impact of cannabis policies on PWID during the ongoing opioid overdose crisis in many settings in the United States and Canada.

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. Methods Data were derived from three prospective cohort studies involving people who use drugs in Vancouver, Canada. Latent class growth analysis was applied to identify opioid use trajectories based on individual-level observations three years before starting OAT. Multivariable generalized linear mixed model was used to examine whether engaging in OAT was associated with lower risk of illicit opioid use among participants with different pre-treatment opioid use trajectories. Results 464 participants were included in the study between September 2005 and November 2018. Two pre-treatment opioid use trajectories were identified: high frequency users (246, 53.0%) and gradually increasing frequency users (218, 47.0%). We observed different strengths of association between OAT engagement and illicit opioid use among high frequency users (adjusted odds ratio [AOR] = 0.36, 95% Confidence Interval [CI]: 0.20 – 0.63) and gradually increasing frequency users (AOR = 0.91, 95% CI: 0.53 – 1.56). Unstable housing, any stimulant use, experiencing violence, drug dealing, sex work involvement, and incarceration were independently and positively associated with ongoing illicit opioid use. Conclusions Distinct pre-treatment opioid use trajectories are likely to influence treatment outcomes. Research is required to determine if tailored strategies specific to people with different pre-treatment opioid use patterns have potential to improve outcomes of OAT.

INTRODUCTION AND AIMS: People who use illicit drugs (PWUD) are vulnerable to an array of negative health outcomes, and increased hospital services utilisation. PWUD are also a transient population which poses challenges to the provision of optimal health care. The objective of this study was to identify out-migration patterns from Vancouver’s Downtown Eastside (DTES), a neighbourhood where services for PWUD are concentrated, and to estimate the impact of these patterns on hospitalisation events among PWUD. DESIGN AND METHODS: Data were collected through three prospective cohorts of PWUD in Vancouver, which were linked with health administrative data. Latent class growth analysis was used to define migration trajectory groups. Poisson regression was used to estimate the effect of migration patterns on hospitalisation events. RESULTS: A total of 1180 participants were included in the study. Four latent classes were identified: early migration out (243, 20.6%); frequent revisit (112, 9.5%); late migration out (219, 18.6%); and consistently living in the DTES (606, 51.4%). Compared with those who consistently lived in the DTES, participants in the early migration out group had lower hospitalisation events (adjusted rate ratio = 0.65; 95% confidence interval: 0.48–0.90). DISCUSSION AND CONCLUSION: We found that PWUD who migrated out of the DTES early had lower hospitalisation events compared to those who consistently lived in the DTES, which may be a function of lesser addiction severity among this trajectory group. These findings underscore a need to provide transitional health and social service supports for other trajectory groups in an effort to minimise hospitalisation for preventable causes.

Background North America is facing an unprecedented public health crisis of opioid-related morbidity and mortality, increasingly as a result of the introduction of illicitly manufactured fentanyl into the street drug market. Although the treatment of opioid use disorder (OUD) is a key element in the response to the opioid overdose epidemic, currently available pharmacotherapies (e.g., methadone, buprenorphine) may not be acceptable to or effective in all patients. Available evidence suggests that slow-release oral morphine (SROM) has similar efficacy rates as methadone with respect to promoting abstinence, and with improvements in a number of patient-reported outcomes among persons using heroin. However, little is known about the relative effectiveness and acceptability of SROM compared to methadone in the context of fentanyl use. This study aims to address this research gap. Methods pRESTO is a 24-week, open-label, two arm, non-inferiority, randomized controlled trial comparing SROM versus methadone for the treatment of OUD. Participants will be 298 clinically stable, non-pregnant adults with OUD, recruited from outpatient clinics in Vancouver, Canada, where the majority of the illicit opioids are contaminated with fentanyl. The primary outcome is suppression of illicit opioid use, measured by bi-weekly urine drug screens. Secondary outcomes include: treatment retention, medication safety, overdose events, treatment satisfaction, psychological functioning, changes in drug-related problems, changes in quality of life, opioid cravings, other substance use, and cost-effectiveness. Discussion pRESTO will be among the first studies to evaluate treatment options for individuals primarily using synthetic street opioids, providing important evidence to guide treatment strategies for this population.

Throughout the world, Indigenous populations experience a disproportionate burden of HIV infection. Maximally-assisted therapy (MAT) is an interdisciplinary care intervention that includes ART dispensation to support individuals with a history of addiction and homelessness. This study sought to longitudinally evaluate the relationship between engagement in MAT and achieving optimal adherence using data from an ongoing cohort of HIV-positive individuals who use drugs in Vancouver, Canada, where HIV/AIDS treatment is offered at no cost. Between December 2005 and November 2016, 354 HIV-positive Indigenous participants were enrolled and data were analyzed using generalized mixed-effects (GLMM) and marginal structural modeling. In both multivariable analyses, engagement in MAT was independently associated with optimal adherence to ART (GLMM: AOR = 4.92, 95% CI 3.18-7.62; marginal structural model: AOR = 5.76, 95% CI 3.34-9.96). MAT-based programmes could be a part of a renewed evidence-base to elevated levels of preventable HIV/AIDS-associated morbidity, mortality and viral transmission among Indigenous peoples in Canada.

INTRODUCTION AND AIMS People who use illicit drugs (PWUD) often engage in drug use during hospitalisation. Adverse outcomes may arise from efforts to conceal inpatient drug use, especially in hospital settings that rely on abstinence-based policies. Harm reduction interventions, including supervised drug consumption services, have not been well studied in hospital settings. This study examines factors associated with willingness to use an in-hospital supervised inhalation room (SIR) among people who smoke crack cocaine in Vancouver, Canada. DESIGN AND METHODS Cross-sectional data from two open prospective cohorts of PWUD involving people who smoke crack cocaine were collected between June 2013 and May 2014. Multivariable logistic regression analyses were used to identify factors associated with willingness to use an in-hospital SIR. RESULTS Among 539 participants, 320 (59.4%) reported willingness to use an in-hospital SIR. Independent factors positively associated with willingness included: ever used drugs in hospital [adjusted odds ratio (AOR) = 1.89], and daily non-injection crack use (AOR = 1.63). Difficulty accessing new crack pipes (AOR = 0.51) was negatively associated with willingness (all P

Childhood traumatic experiences can disrupt attachment, influence personality development, and precipitate chronic disease. Although the repercussions of these experiences may also pose a barrier to healthcare, few studies have examined the association between childhood trauma and access to healthcare. Therefore, we sought to investigate whether a history of childhood trauma is associated with self-reported inability to access hospital care among persons who inject drugs (PWID). Data were derived from two prospective cohorts of PWID in Vancouver, Canada. We used multivariable generalized estimating equations to examine associations between five types of childhood trauma and self-reported inability to access hospital care, both overall and specifically due to perceived mistreatment by hospital staff. In total, 300 participants (18.3%) reported having tried but being unable to access hospital care in the previous 6 months at some point during the study period; the primary reason was perceived mistreatment by hospital staff (32.1%). In multivariable analyses, childhood emotional abuse was independently associated with self-reported inability to access hospital care, adjusted odds ratio (AOR) = 1.51, 95% CI [1.03, 2.20]. Childhood physical neglect was also independently associated with inability to access care due to perceived mistreatment by hospital staff, AOR = 1.80, 95% CI [1.11, 2.93]. This suggests potentially damaging consequences of early trauma in adult PWID populations. Further, this study emphasizes the need for trauma-informed models of care as well as the need to improve therapeutic alliances with survivors of childhood trauma in the PWID population.

Introduction and aims Street-involved youth are known to be at elevated risk of initiating injection drug use. However, the impact of so-called 'gateway' drugs, such as cannabis, on injection initiation is unknown. The objective of this study was to examine the association between cannabis use and initiation of injection drug use among a prospective cohort of street-involved youth in Vancouver, Canada. Design and methods Data for this study were collected from the At-Risk Youth Study. From September 2005 to May 2015, participants aged 14-26 who reported illicit drug use were recruited into this open prospective cohort study. An extended Cox regression model with time-updated covariates was used to identify factors independently associated with injection initiation. Results During the study period, 481 street-involved youth were included in this study. Of these, 228 (47.4%) reported at least daily cannabis use, and 103 (21.4%) initiated injection drug use. In a multivariable analysis, ≥daily cannabis use was associated with slower rates of injection initiation (adjusted relative hazard 0.66, 95% confidence interval 0.45-0.98; P = 0.038). Sub-analyses revealed that cannabis use was negatively associated with initiation of injection stimulants but not initiation of injection opioids. Discussion and conclusions Given the expansion of cannabis legalisation throughout North America, it is encouraging that cannabis use was associated with slower time to initiation of injection drug use in this cohort. This finding challenges the view of cannabis as a gateway substance that precipitates the progression to using harder and more addictive drugs.

Background and objectives Alcohol is a major contributor to premature disability and death among youth, often due to physical trauma, violence, and suicide. The purpose of this study was to longitudinally examine the association between hazardous alcohol use and experiences of violence among a cohort of street-involved youth. Methods Data were derived from the At-Risk Youth Study (ARYS), a prospective cohort of street-involved youth who use illicit substances in Vancouver, Canada. The outcome of interest was hazardous alcohol use defined by the US National Institute on Alcohol Abuse and Alcoholism as >14 drinks/week or >5 drinks on one occasion for men, and >7 drinks/week or >4 drinks on one occasion for women. We used Generalized Estimating Equations (GEE) analyses to examine factors independently associated with hazardous alcohol use. Results Between 2005 and 2014, 1,149 drug-using youth were recruited and 423 (36.8%) reported hazardous alcohol use in the previous 6 months at study baseline. In multivariable GEE analyses, intimate partner violence (Adjusted Odds Ratio [AOR] = 1.53, 95% Confidence Interval [95%CI] = 1.12-2.10), and non-partner physical assault (AOR = 1.39, 95%CI = 1.21-1.59) were independently associated with hazardous alcohol use after adjusting for multiple potential confounders. Discussion and conclusions A considerable proportion of youth in this setting reported hazardous alcohol use, which was independently associated with experiencing recent intimate and non-partner violence. Scientific significance Combined interventions for violence and hazardous alcohol use should be integrated into service provision programs for street-involved youth. (Am J Addict 2017;26:852-858).

Background and Aims Injecting illicit drugs in public settings has been linked to a higher risk of a range of drug-related harms, including overdose and HIV infection. However, the factors associated with public injecting among HIV-positive individuals have not been previously explored. We investigated the links between public drug injecting, drug-related harm, and HIV treatment measures among a cohort of HIV-positive persons who inject drugs (PWID) in a Canadian setting. Methods We used data from a prospective cohort of HIV-positive PWID recruited from community settings in Vancouver, Canada, linked to comprehensive clinical monitoring data in the context of an ongoing Treatment-as-Prevention (TasP) initiative to examine harms associated with public injecting. We used generalized linear mixed-effects analyses to identify longitudinal factors associated with self-reported public drug injection. Results Between 2005 and 2014, 626 HIV-seropositive PWID were recruited, of whom 213 (34%) reported public injection in the preceding 180 days. In a longitudinal multivariable model, public injection was positively associated with daily heroin injection (Adjusted Odds Ratio [AOR] = 2.63), incarceration (AOR = 1.78), and detectable plasma HIV-1 RNA viral load (VL, AOR = 1.42). Conclusions Public injecting was linked to numerous drug-related harms among HIV-seropositive PWID in this setting. Given its link with detectable VL, an important marker of poor HIV treatment outcomes, our findings support prioritizing individuals engaged in public injecting with harm reduction strategies as well as clinical and social supports as a part of TasP-based efforts to prevent HIV-related morbidity and mortality, and HIV transmission.

BACKGROUND: While exposure to traumatic events and subsequent post-traumatic stress disorder (PTSD) are common among people who use drugs (PWUD), little is known about gender-based differences associated with PTSD in this population. We explore gender-based differences in factors associated with a probable PTSD diagnosis in a cohort of PWUD from Vancouver, Canada. METHODS: Data were collected through the Vancouver Injection Drug Users Study (VIDUS) and the AIDS Care Cohort to Evaluate Exposure to Survival Services (ACCESS), two community-recruited cohorts of PWUD. Participants were administered the PTSD Checklist for DSM-5. Multivariable logistic regression was used to investigate social-structural factors and substance use patterns and behaviours associated with a probable PTSD diagnosis, stratified by self-identified gender. PTSD symptom clusters and brief descriptions of the worst traumatic event experienced were also reported. RESULTS: Between December 2016 and December 2018, of 797 eligible participants, 295 (37.0%) identified as women. PTSD was more commonly reported in women compared to men (53.2% vs. 31.5%, p

Objectives:Although take-home naloxone (THN) programs are integral in strategies to prevent overdose deaths among opioid users, the uptake of THN among people who use drugs (PWUD) (including non-opioid users) is unknown. The objectives of this study were to determine awareness, possession, and use of THN among PWUD in Vancouver, Canada, and identify barriers to adopting this strategy.Methods:From December 1, 2014, to May 29, 2015, participants in 2 prospective cohort studies of PWUD in Vancouver completed a standardized questionnaire, which asked about awareness, possession, and use of THN; sociodemographic characteristics; and drug use patterns. We conducted multivariable logistic regression analyses to determine factors independently associated with awareness and possession of THN.Results:Of 1137 PWUD, 727 (64%) reported at least 1 previous overdose ever, and 220 (19%) had witnessed an overdose in the previous 6 months. Although 769 (68%) participants overall reported awareness of THN, only 88 of 392 (22%) opioid users had a THN kit, 18 (20%) of whom had previously administered naloxone. Factors that were positively associated with awareness of THN included witnessing an overdose in the previous 6 months (adjusted odds ratio [aOR] = 2.23; 95% confidence interval [CI], 1.49-3.34; P < .001), possession of THN (aOR = 1.85; 95% CI, 1.11-3.06; P = .02), younger age (aOR = 1.02; 95% CI, 1.01-1.04; P = .003), white race (aOR = 1.67; 95% CI, 1.27-2.19; P < .001), hepatitis C infection (aOR = 1.63; 95% CI, 1.13-2.36; P = .01), residing in Vancouver’s Downtown Eastside neighborhood (aOR = 1.93; 95% CI, 1.47-2.53; P < .001), and at least daily heroin injection (aOR = 1.69; 95% CI, 1.09-2.62; P < .02).Conclusion:Efforts to improve knowledge of and participation in the THN program may contribute to reduced opioid overdose mortality in Vancouver.

Introduction and Aims Compared to the general population of youth, health-related disparities experienced by youth exposed to the child welfare system are well documented. Amongst these vulnerabilities are elevated rates of substance use, including injection drug use; however, less is known about when these youth transition to this high-risk behaviour. We sought to assess whether having a history of government care is associated with initiating injection drug use before age 18. Design and Methods Between September 2005 and May 2014, data were derived from the At-Risk Youth Study, a cohort of street-involved youth who use illicit drugs in Vancouver, Canada. Multivariable logistic regression analysis was employed to examine the relationship between early initiation of injection drug use and having a history of being in government care. Results Among the 581 injecting street-involved youth included, 229 (39%) reported initiating injection drug use before 18 years of age. In multivariable analysis, despite controlling for a range of potential confounders, having a history of government care remained significantly associated with initiating injection drug use before age 18 (adjusted odds ratio = 1.69; 95% confidence interval: 1.15–2.48). Discussion and Conclusions Youth with a history of being in government care were significantly more likely to initiate injection drug use before age 18 than street-involved youth without a history of being in care. These findings imply that youth in the child welfare system are at higher risk and suggest that interventions are needed to prevent transitions into high-risk substance use among this population.

OBJECTIVES HIV treatment-as-prevention campaigns emphasize early diagnosis and immediate access to care and antiretroviral therapy for HIV-positive individuals in order to increase levels of plasma HIV RNA viral load (VL) suppression. However, the possible role of harm reduction-based programmes in this objective has not yet been well evaluated. The objective of the study was to examine the relationship between being a client of the Dr. Peter Centre (DPC; an HIV/AIDS-focused adult integrated health programme) and VL suppression among highly active antiretroviral therapy (HAART)-exposed HIV-positive people who use illicit drugs (PWUD) in Vancouver, Canada. METHODS Data were derived from the AIDS Care Cohort to Evaluate Exposure to Survival Services (ACCESS) study, a study of a community-recruited cohort of HIV-positive PWUD. A marginal structural model using inverse probability of treatment weights was used to estimate the longitudinal relationship between being a DPC client and exhibiting a VL < 50 HIV-1 RNA copies/mL plasma. RESULTS Between 2005 and 2014, 746 HAART-exposed participants were included in the study, of whom 269 (36.1%) reported being a DPC client at some time during the study period. A marginal structural model estimated a 1.54 greater odds of achieving VL suppression (95% confidence interval 1.20-1.99) among DPC clients. CONCLUSIONS Our findings demonstrate that participating in an innovative HIV/AIDS-focused adult integrated health programme that provides a broad range of clinical, harm reduction, and support services may contribute to optimizing the benefits of HAART in terms of morbidity, mortality and viral transmission among PWUD, and as a result help to fulfill the goals of the treatment-as-prevention strategy.

OBJECTIVES Despite the high burden of hepatitis C virus (HCV)-related morbidity and mortality among HIV-positive people who use illicit drugs (PWUD), uptake of interferon-based treatments for HCV infection has been negligible among this group. Direct-acting antiviral (DAA) therapies offer an opportunity to expand treatment access among this population. The aim of this study was to explore willingness to use DAA-based regimens among HIV/HCV-coinfected PWUD in Vancouver, Canada. METHODS Data were drawn from the AIDS Care Cohort to evaluate Exposure to Survival Services (ACCESS), a prospective cohort of HIV-positive PWUD. Using logistic regression analyses, we investigated factors associated with willingness to use DAA-based regimens among HIV/HCV-coinfected participants. RESULTS Of 418 HIV/HCV-coinfected PWUD surveyed between June 2014 and May 2015, 295 (71%) were willing to use DAA-based regimens. In multivariable analysis, participants enrolled in methadone maintenance therapy [adjusted odds ratio (AOR) 1.61; 95% confidence interval (CI) 1.04-2.51], those with a recent assessment by an HCV specialist (AOR 2.02; 95% CI 1.28-3.19) and those who perceived that HCV infection was affecting their health (AOR 2.49; 95% CI 1.41-4.37) were more likely to be willing to use DAA-based regimens. CONCLUSIONS Overall, this study found a high prevalence of willingness to use DAA-based regimens among HIV/HCV-coinfected PWUD in Vancouver. Importantly, enrolment in methadone maintenance therapy was positively associated with willingness, suggesting that integrated models of HIV, HCV and addiction care should be explored as a way to address HCV-related morbidity and mortality among HIV/HCV-coinfected PWUD.

Introduction Socioeconomically marginalized people who use illicit drugs (PWUD) often engage in alternative income generating activities to meet their basic needs. These activities commonly carry a number of health and social risks, which may prompt some PWUD to consider addiction treatment to reduce their drug use or drug-related expenses. We sought to determine whether engaging in certain forms of income generation was independently associated with self-reported need for addiction treatment among a cohort of PWUD in Vancouver, Canada. Methods Data from two prospective cohorts of PWUD in Vancouver were used in generalized estimating equations to identify factors associated with self-reported need for addiction treatment, with a focus on income generating activities. Results Between June 2013 and May 2014, 1285 respondents participated in the study of whom 483 (34.1%) were female and 396 (30.8%) indicated that they needed addiction treatment. In final multivariate analyses, key factors significantly and positively associated with self-reported need for addiction treatment included engaging in illegal income generating activities (adjusted odds ratio [AOR] = 1.96, 95% confidence interval [CI}: 1.11–3.46); sex work (AOR = 1.61, 95% CI: 1.05–2.47), homelessness (AOR = 1.65, 95% CI: 1.22–2.25); and recent engagement in counselling (AOR = 1.85, 95% CI: 1.40–2.44). Discussion Our results suggest that key markers of socioeconomic marginalization are strongly linked with a stated need for addiction treatment. These findings underscore the need to provide appropriate and accessible addiction treatment access to marginalized PWUD and to consider alternative approaches to reduce socioeconomic disadvantage.

Objectives Prescription opioid (PO) injection among people who use illicit drugs (PWUD) is an ongoing concern, yet little is known about drug use trajectories associated with initiating PO injection, including potential associations with heroin use. This study aimed to identify predictors of PO injection initiation among PWUD, and examine trends in heroin use before and after initiating PO injection. Methods Data were merged from three cohorts of PWUD recruited between September 2005 and November 2015. Predictors of PO injection initiation were identified using extended Cox regression models. Trends in heroin use pre- and post-initiation were examined with McNemar’s test and compared to matched controls with linear growth curve models. Results Among 1580 participants, 247 initiated PO injection yielding an incidence density of 3.9 (95% Confidence Interval [CI]: 3.4–4.4) per 100 person-years. In a multivariable analysis, independent predictors of PO injection initiation included heroin injection (Adjusted Hazard Ratio [AHR] = 4.39, 95% CI: 3.24–5.95) and non-injection PO use (AHR = 1.99, 95% CI: 1.25–3.17). In a sub-analysis, compared to matched controls, PO injection corresponded with elevated heroin use post-initiation ( p ≤ 0.05). Discussion In this study, heroin use and non-injection PO use strongly predicted PO injection initiation. Those who initiated PO injecting had elevated heroin use patterns post-initiation compared to controls. These findings suggest that transitioning to PO injection does not appear to be a substitute for heroin use among PWUD. These findings highlight the importance of addressing PO injection in harm reduction and treatment settings.

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. We assessed use patterns for heroin, illicit prescription opioid, cocaine, crack cocaine, crystal methamphetamine, cannabis, daily alcohol use, and benzodiazepines. Segmented regression was conducted to compare the trends of substance use between pre-treatment and post-treatment periods. Results The study included 1107 participants. After OAT engagement, we observed an immediate decline in the proportion as well as a decreasing trend for heroin (Adjusted Odds Ratio (AOR): 0.80, 95% confidence interval (CI): 0.77, 0.83), illicit prescription opioid (AOR: 0.87, 95% CI: 0.83, 0.90), and benzodiazepines (AOR: 0.73, 95 % CI: 0.67, 0.80). There was no significant difference comparing the pre-treatment and post-treatment trends for cocaine, crack cocaine, crystal methamphetamine, and cannabis. However, higher growth slope was noted during the post-treatment period for daily alcohol use (P = 0.016). Conclusions We observed significant reduction in illicit opioids use following OAT initiation, but not for stimulant and cannabis. The increasing problematic use of alcohol may pose challenges to the safety and effectiveness of OAT. Development of comprehensive and tailored treatment strategies is needed for poly-substance users accessing OAT.

Although the health and community benefits of supervised injection facilities are well documented, little is known about long-term patterns of utilization of this form of health service. The present study seeks to longitudinally characterize discontinuation of use of a supervised injection facility in Vancouver, Canada.Data were drawn from 2 community-recruited prospective cohorts of people who inject drugs between December 2005 and December 2016. In 2018, extended Cox regression for recurrent events was used to examine factors associated with time to cessation of supervised injection facility use during periods of active injection.Of 1,336 people who inject drugs that were followed for a median of 50 months, 847 (63.4%) participants reported 1,663 6-month periods of supervised injection facility use cessation while actively injecting drugs (incidence density of 26.6 events per 100 person-years). An additional 2,282 (57.8%) of the total 3,945 6-month periods of supervised injection facility use cessation occurred during periods of injection cessation. In multivariable analyses, enrollment in methadone maintenance therapy (adjusted hazard ratio=1.41) and HIV seropositivity (adjusted hazard ratio=1.23) were positively associated with supervised injection facility use cessation during periods of active injection, whereas homelessness (adjusted hazard ratio=0.59), at least daily heroin injection (adjusted hazard ratio=0.70), binge injection (adjusted hazard ratio=0.68), public injection (adjusted hazard ratio=0.67), nonfatal overdose (adjusted hazard ratio=0.73), difficulty accessing addiction treatment (adjusted hazard ratio=0.69), and incarceration (adjusted hazard ratio=0.70) were inversely associated with this outcome (all p0.05). The most commonly reported reasons for supervised injection facility use cessation were injection drug use cessation (42.3%) and a preference for injecting at home (30.7%).These findings suggest that this supervised injection facility successfully retains people who inject drugs at elevated risk of drug-related harms and indicate that many supervised injection facility clients neither use this service nor inject drugs perpetually.

Background: Despite the enormous burden of disease attributable to drug and alcohol addiction, there remain major challenges in implementing evidence-based addiction care and treatment modalities. This is partly because of a persistent lack of accessible, specialized training in addiction medicine. In response, a new online certificate in addiction medicine has been established in Vancouver, Canada, free of charge to participants globally. Objective: The objective of this study was to evaluate and examine changes in knowledge acquisition among health care professionals before and after the completion of an online certificate in addiction medicine. Methods: Learners enrolled in a 17-module certificate program and completed pre- and postknowledge tests using online multiple-choice questionnaires. Knowledge acquisition was then evaluated using a repeated measures t test of mean test scores before and after the online course. Following the certificate completion, a subset of learners completed the online course evaluation form. Results: Of the total 6985 participants who registered for the online course between May 15, 2017 and February 22, 2018, 3466 (49.62%) completed the online pretest questionnaire. A total of 1010 participants completed the full course, achieving the required 70% scores. TThe participants self-reported working in a broad range of health-related fields, including nursing (n=371), medicine (n=92), counseling or social work (n=69), community health (n=44), and pharmacy (n=34). The median graduation year was 2010 (n=363, interquartile range 2002-2015). Knowledge of the addiction medicine increased significantly postcertificate (mean difference 28.21; 95% CI 27.32 to 29.10; P