Drugs In Vancouver Research Articles

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

BackgroundPeople who require help injecting illicit drugs experience elevated rates of a range of health-related harms, including overdose and acquisition of blood-borne pathogens. In response, some supervised injection services (SIS) in Canada have begun to permit clients to be physically injected by fellow clients or staff members. However, little is known about uptake and characteristics of clients who engage in this practice. We therefore sought to examine factors associated with receiving injection assistance at SIS among people who require help injecting drugs in Vancouver, Canada. MethodsData were drawn from two community-recruited prospective cohort studies of people who inject drugs (PWID). We used multivariable generalized estimating equation (GEE) analyses with time-updated covariates to identify factors associated with self-reported receipt of injection assistance at SIS. ResultsBetween June 2017 and December 2018, 319 individuals who reported having recently required help injecting were included in the study. Of these, 160 (51.0%) were women and the median age was 42 years at baseline. In total, 54 (16.9%) participants reported receiving injection assistance at a SIS at least once over an average of 3.3 months of follow-up. In multivariable GEE analyses, recent homelessness (Adjusted Odds Ratio [AOR] = 2.04; 95% confidence interval [CI]: 1.13 – 3.66), fentanyl injection (AOR = 3.45; 95% CI: 1.42 – 8.41), non-fatal overdose (AOR = 1.86; 95% CI: 1.02 – 3.38) and enrolment in methadone maintenance therapy (AOR = 1.89; 95% CI: 1.03 – 3.47) were associated with increased odds of receiving injection assistance at SIS. ConclusionAlthough uptake of assisted injection at SIS was relatively low among this sample of people who require help injecting, this practice was associated with several indicators of structural vulnerability and drug-related risk. These findings suggest that accommodating assisted injection within SIS may be providing opportunities to engage and reduce harms among higher-risk subpopulations of PWID in this setting.

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

BackgroundOpioid 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. MethodsData 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. Results464 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. ConclusionsDistinct 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.

Long-term benefits of providing transitional services to youth aging-out of the child welfare system: Evidence from a cohort of young people who use drugs in Vancouver, Canada

BackgroundYouth aging-out of the child welfare system (CWS) experience numerous vulnerabilities including, elevated rates of substance use and substance use disorders. Calls to improve services to transition youth to independence are common; however, evidence of the long-term impacts associated with transitional service utilization is scarce. Further, existing services frequently lack appropriate supports for substance using youth and it is unknown if youth are able to access such services. In the present study, we assess the relationship between transitional service utilization and health and social outcomes among a cohort of people who use drugs (PWUD) that aged-out of the CWS. MethodsData were obtained from two harmonized cohorts of PWUD in Vancouver, Canada. Those who reported aging-out were asked about service utilization, availability, barriers, and interest across seven categories of transitional services. Multivariable logistic regression analyses were conducted to assess the relationship between having previously utilized transitional services and current health and social outcomes. ResultsBetween December 2014 and November 2017, 217 PWUD reported having previously aged-out of the CWS. Across service categories, reported service utilization prevalence ranged from 16.6-61.8% while unmet demand ranged from 64.8-78.4%. In multivariable analyses, compared to individuals who utilized ≤1 service while aging-out, having utilized 4-7 services was significantly associated with reduced odds of current homelessness (adjusted odds ratio [AOR]=0.29) and engaging in daily drug use (AOR=0.35) (both p<0.05). ConclusionFindings suggest that this understudied high-risk population of PWUD and aged-out of the CWS experience long-term benefits associated with transitional service utilization and are interested and willing to engage in these services. However, given high unmet demand, findings also highlight considerable gaps in service delivery and support calls for extending the age of emancipation for all youth in the CWS and in particular, for additional harm reduction and substance use supports embedded into service models.

Withdrawal-associated injury site pain prevalence and correlates among opioid-using people who inject drugs in Vancouver, Canada

BackgroundPain can return temporarily to old injury sites during opioid withdrawal. The prevalence and impact of opioid withdrawal-associated injury site pain (WISP) in various groups is unknown. MethodsUsing data from observational cohorts, we estimated the prevalence and correlates of WISP among opioid-using people who inject drugs (PWID). Between June and December 2015, data on WISP and opioid use behaviours were elicited from participants in three ongoing prospective cohort studies in Vancouver, Canada, who were aged 18 years and older and who self-reported at least daily injection of heroin or non-medical presciption opioids. ResultsAmong 631 individuals, 276 (43.7 %) had a healed injury (usually pain-free), among whom 112 (40.6 %) experienced WISP, representing 17.7 % of opioid-using PWID interviewed. In a multivariable logistic regression model, WISP was positively associated with having a high school diploma or above (Adjusted Odds Ratio [AOR] = 2.23, 95 % Confidence Interval [CI]: 1.31−3.84), any heroin use in the last six months (AOR = 2.00, 95 % CI: 1.14−3.57), feeling daily pain that required medication (AOR = 2.06, CI: 1.18−3.63), and negatively associated with older age at first drug use (AOR = 0.96, 95 % CI: 0.93−0.99). Among 112 individuals with WISP, 79 (70.5 %) said that having this pain affected their opioid use behaviour, of whom 57 (72.2 %) used more opioids, 19 (24.1 %) avoided opioid withdrawal, while 3 (3.8 %) no longer used opioids to avoid WISP. ConclusionsWISP is prevalent among PWID with a previous injury, and may alter opioid use patterns. Improved care strategies for WISP are warrented.

Perspectives of HIV-positive and -negative people who use drugs regarding the criminalization of HIV non-disclosure in Canada: a qualitative study

BackgroundWhile previous research has identified how criminalization of HIV non-disclosure can have deleterious effects on those living with HIV, the perspectives of people who use drugs – a population disproportionately affected by HIV– should be more meaningfully considered in these discussions.MethodsUsing constant comparative techniques, data from 60 interviews with men and women living with and without HIV and who use drugs in Vancouver were analyzed to explore their perceptions about Canada’s HIV non-disclosure legal framework.ResultsParticipants’ perspectives on the framework involved three themes: understandings of HIV risk; HIV-related stigma; and their own experiences with HIV. While several participants favored the punitive character of the legal framework, these arguments were premised on misinformed and stigmatized assumptions regarding HIV.ConclusionsThe paper concludes by discussing the challenges and opportunities for resisting HIV stigma and misconceptions about HIV within the context of personal accounts that, at times, support criminalization of non-disclosure.

The Cedar Project - Mobile Phone Use and Acceptability of Mobile Health Among Young Indigenous People Who Have Used Drugs in British Columbia, Canada: Mixed Methods Exploratory Study.

BackgroundIndigenous leaders continue to be concerned about high rates of HIV and barriers to HIV treatment among young Indigenous people involved in substance use. Growing evidence suggests that using mobile phones for health (mHealth) may be a powerful way to support connection with health services, including HIV prevention and treatment.ObjectiveThis study examined the patterns of mobile phone ownership and use among young Indigenous people who have used drugs living with or vulnerable to HIV and explored the acceptability of mHealth to support access to health care in this population.MethodsThe Cedar Project is a cohort study involving young Indigenous people who have used drugs in Vancouver and Prince George, British Columbia. This mixed methods exploratory study involved 131 Cedar Project participants enrolled in our WelTel mHealth program. At enrollment, participants completed a questionnaire related to mobile phone use and interest in mHealth. Data were linked to Cedar Project questionnaires and serodata. We present comparative statistics (quantitative) and results of a rapid thematic analysis (qualitative) related to mobile phone patterns and interest in receiving mHealth.ResultsLess than half of the participants (59/130; 45.4%) reported owning a phone. Among those with a phone, the majority owned a smartphone (46/59; 78%). Most participants with a phone reported having an unlimited texting plan (39/55; 71%), using the internet on their phone (44/59; 75%), and texting daily (44/55; 80%). A majority reported that using a mobile phone for health would be invaluable (120/130; 92.3%). There were no differences in mHealth acceptance between participants who owned a phone and those who did not (P>.99). All but one participant living with HIV felt using a mobile phone would be helpful for their health, while a small proportion of HIV-negative participants remained unsure (1.9% vs 11.7%; P=.047). In response to open-ended questions asking why using a mobile phone may be helpful for health, participants identified a diverse set of anticipated benefits: (1) connection for emotional, mental, and spiritual support, (2) connection to family, (3) staying in touch and/or being reachable, (4) overcoming current barriers to phone use, (5) convenience, privacy, and safety, and (6) access to health care and emergency services.ConclusionsWe observed high acceptance and interest in using mobile phone technology for health despite low rates of personal mobile phone connectivity among young Indigenous people who have used drugs living with and vulnerable to HIV in British Columbia, Canada. Mobile phones were viewed as a way to support connections and relationships that are seen as critical to health and well-being among young Indigenous people in this study. Findings may be useful for health care providers preparing to scale up mHealth programs to support HIV prevention and treatment in this population.

Elevated prevalence of self-reported unintentional exposure to fentanyl among women who use drugs in a Canadian setting: A cross-sectional analysis

BackgroundThe United States and Canada are in the midst of an overdose epidemic, fueled by illicitly manufactured fentanyl. While marked differences in vulnerability to drug-related harm between men and women who use drugs is well characterized, the extent to which gender differences manifest in the present overdose crisis remains understudied. We examined differences in self-reported unintentional exposure to fentanyl between men and women who use drugs. MethodologyData were derived from three prospective cohorts of people who use drugs in Vancouver, Canada. Survey data were extracted on individuals who self-reported having used drugs known or believed to contain fentanyl in the past 30 days between December 2016 and November 2017. We used multivariable logistic regression (MLR) to examine the relationship between self-identified gender (woman vs. man) and self-reported unintentional exposure to fentanyl. As a sub-analysis, correlates of self-reported unintentional exposure to fentanyl were identified using MLR, stratified by gender. ResultsOf 578 eligible participants, including 219 (37.9%) women, 200 (33.2%) perceived their exposure to fentanyl as unintentional (40.2% among women and 29.0% among men). In the MLR, being a woman was positively associated with self-reported unintentional fentanyl exposure (adjusted odds ratio = 2.11; 95% confidence interval: 1.45–3.09). Among women at least daily heroin use was negatively associated with self-reported unintentional fentanyl exposure, while perceiving a high or moderate risk of overdosing on fentanyl was positively associated with outcome. Among men older age was positively associated with self-reported unintentional fentanyl exposure, while injection drug use and at least daily heroin use was negatively associated with the outcome (all p<0.05). ConclusionsWomen were more than two times as likely to self-report they were unintentionally exposed to fentanyl compared to men. These findings highlight the urgent need to further understand experiences of gender-based risk differences and develop gender-focused interventions and policies aimed at preventing drug-related harm.

Changes in drug use behaviors coinciding with the emergence of illicit fentanyl among people who use drugs in Vancouver, Canada

ABSTRACT Background: With the emergence of illicitly-manufactured fentanyl, drug overdose deaths have risen in unprecedented numbers. In this context, there is an urgent need to characterize potential changes in drug use behaviors among people who use drugs (PWUD). Objective: To examine changes in drug use behaviors following the emergence of illicit fentanyl among people who use drugs (PWUD). Methods: Data for this cross-sectional analysis was derived from three prospective cohorts of PWUD between December 2016 and May 2017 in Vancouver, Canada. Multivariable logistic regression was used to determine factors associated with self-reported behavior changes (binary variable “yes” or “no”) following the emergence of illicit fentanyl. Results: Among 999 participants [363 (36.3%) females], 388 (38.8%) reported some behavior change. The remaining 611 (61.2%) reported no change in behavior; 240 (39.3%) of these individuals had recently been exposed to fentanyl. In multivariable analyses, factors independently associated with behavior change included recent non-fatal overdose (Adjusted Odds Ratio [AOR] = 2.28), active injection drug use (AOR = 1.96), being on opioid agonist therapy (AOR = 1.80), and urine drug screen positive for fentanyl (AOR = 1.45), (all p < .05). Conclusion: The majority of PWUD in our sample did not change their drug use behavior despite a high prevalence of fentanyl exposure, indicating a need for targeted behavior change messaging and overdose prevention efforts such as naloxone and addiction treatment for this sub-population of PWUD. Further, the high fentanyl exposure observed in our sample suggests a need to address upstream structural factors shaping the overdose risk in addition to individual behavioral change.

Characterising the increasing prevalence of crystal methamphetamine use in Vancouver, Canada, from 2006-2017: A gender-based analysis.

Methamphetamine use is increasing in North America and is associated with numerous negative health effects and social harms. As drug-related harms are often gendered, this study sought to examine the differential impacts of gender on the trends, risk factors and health implications of crystal methamphetamine use among a Canadian cohort of people with high rates of injection polysubstance use. Data were collected from two prospective cohorts of people who inject drugs in Vancouver, Canada. We examined trends in reported crystal methamphetamine use from 2006-2017 using the Cochrane-Armitage test for trend. We used multivariable generalised estimating equations, stratified by gender, to determine independent risk factors and health outcomes associated with crystal methamphetamine use. In total, 1984 participants were included in the study, including 694 (35%) women. The prevalence of reported crystal methamphetamine use within the previous 6 months rose from 19% in 2006 to 36% in 2017, with a rise seen in both genders (P < 0.001). Reported crystal methamphetamine use was associated with numerous risk behaviours and drug-related harms in both genders, and in women it was associated with an increase in experiences of sexual violence (adjusted odds ratio 1.64, 95% confidence interval 1.18, 2.27). These findings demonstrate the rising prevalence of reported crystal methamphetamine use in Vancouver in a cohort with high rates of polysubstance use. This work highlights drug and sex-related risk behaviours associated with crystal methamphetamine use for both genders, and underscores the need to develop strategies to address the growing use of crystal methamphetamine.

Acceptability of a hypothetical preventative HIV vaccine among people who use drugs in Vancouver, Canada

BackgroundAs research on HIV vaccines continues to advance, studies exploring the feasibility of this intervention are necessary to inform uptake and dissemination strategies with key populations, including people who use drugs (PWUD).MethodsWe conducted 25 in-depth qualitative interviews examining HIV vaccine acceptability among PWUD in Vancouver, Canada. Participants were recruited from an ongoing prospective cohort of HIV-negative PWUD. Data were coded using NVivo, and analyzed thematically.ResultsAcceptability was framed by practical considerations such as cost and side effects, and was influenced by broader trust of government bodies and health care professionals. While an HIV vaccine was perceived as an important prevention tool, willingness to be vaccinated was low. Results suggest that future vaccine implementation must consider how to minimize the burden an HIV vaccine may place on PWUD. Centering the role of health care providers in information dissemination and delivery may assist with uptake.ConclusionsOur findings suggest improvements in care and improved patient-provider relationships would increase the acceptability of a potential HIV vaccine among this population.

Overdose Risk and Acquiring Opioids for Nonmedical Use Exclusively from Physicians in Vancouver, Canada

Background A primary response to the alarming rise in overdose and mortality due to nonmedical prescription opioid (PO) use has been to restrict opioid prescribing; however, little is known about the relationship between obtaining opioids from a physician and overdose risk among people who use POs nonmedically and illicit street drugs. Objectives: Investigate the relationship between non-fatal overdose and acquiring POs exclusively from physicians for the purposes of engaging in nonmedical PO use. Methods: Data were collected between 2013 and 2016 among participants in two harmonized prospective cohort studies of people who use drugs in Vancouver: the At-Risk Youth Study (ARYS) and the Vancouver Injection Drug Users Study (VIDUS). Analyses were restricted to participants who engaged in nonmedical PO use and used generalized estimating equations. Results: Among 599 participants who used POs nonmedically, 82 (14%) individuals reported acquiring POs exclusively from a physician and 197 (33%) experienced a non-fatal overdose at some point over the study period. Acquiring POs exclusively from physicians was significantly and negatively associated with non-fatal overdose in the bivariate analysis (Odds Ratio = 0.60, 95% Confidence Interval (CI): 0.39–0.94) but not the final multivariate analysis (Adjusted Odds Ratio =0.87, 95% CI: 0.53–1.44). Conclusions: Compared to individuals who acquired POs from friends or the streets, participants who acquired POs exclusively from a physician were not at an increased risk of non-fatal overdose. Although responsible opioid prescribing is an important priority, additional strategies to address nonmedical PO use are urgently needed to reduce overdose and related morbidity and mortality.

Impact of migration from an illicit drug scene on hospital outcomes among people who use illicit drugs in Vancouver, Canada.

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. 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. 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). 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.

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

BackgroundAlthough 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. MethodsData 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. ResultsThe 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). ConclusionsWe 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.

Factors Associated With the Use of Supervised Consumption Facilities Among Women Who Inject Drugs in a Canadian Setting.

Supervised consumption facilities (SCFs) are evidence-based harm reduction interventions that have been shown to reduce the risk of social and health-related harms associated with injection drug use. Previous qualitative studies have highlighted important motivations for SCF use among women who use drugs. However, factors associated with SCF use among women have not previously been evaluated. Data were obtained from 2 longitudinal community-recruited cohorts of people who use drugs in Vancouver, Canada between 2003 and 2017. Multivariable generalized estimating equations were used to calculate the odds of SCF use associated with social and structural risk factors for drug-related harm among women who reported injection drug use in the preceding 6-months. A total of 795 participants were included in the study, contributing to 6302 interviews, with 602 participants (76%) reporting SCF use in at least one interview. Multivariable analysis demonstrated daily heroin and crystal methamphetamine injection (Adjusted Odds Ratio [AOR] = 1.32 and 1.65, respectively), injecting in public (AOR = 1.77), binge injection (AOR = 1.22) and lack of housing (AOR = 1.74) to be associated with SCF use. The current study demonstrates higher intensity patterns of drug use, including daily heroin and crystal methamphetamine injection, injecting in public and binge injection, as well as homelessness to be associated with SCF use among women. Future research should identify barriers to SCF use among women to minimize the risk of overdose and other drug-related harms.

Effect of witnessing an overdose on the use of drug checking services among people who use illicit drugs in Vancouver, Canada

ABSTRACT Background Since 2013, fentanyl-contaminated drugs have been driving North America’s opioid-overdose epidemic. Drug checking, which enables people who use illicit drugs (PWUD) to test and receive feedback regarding the contents of their drugs, is being considered as a potential tool to address the toxic drug supply. While some PWUD witness overdoses, little is known about the impact of these experiences on subsequent risk reduction practices. Objective The purpose of this study was to examine the effect of witnessing an overdose on drug checking service use. Methods Data were derived from prospective cohorts of PWUD in Vancouver, Canada, a setting with a community-wide fentanyl overdose crisis, between June 1, 2018 and December 1, 2018. Multivariable logistic regression was used to estimate the effect of witnessing an overdose on drug checking service use. Results 1,426 participants were eligible for the study, including 530 females; 767 (53.8%) participants reported witnessing an overdose and 196 (13.7%) reported using drug checking services in the last 6 months. In multivariable analyses, after adjusting for a range of confounders including the use of fentanyl, witnessing an overdose was positively associated with drug checking service use (adjusted odds ratio = 2.32; 95% confidence interval: 1.57–3.49). Conclusion Our findings suggest that witnessing an overdose may motivate PWUD to use drug checking services. Given that only a small proportion of PWUD in the study reported using drug checking services, our findings highlight the need to continue to scale-up a range of overdose prevention interventions.

Supervised injection's positive impact transcends reduced OD risk alone

Not only do the supervised injection facilities (SIFs) that have not yet made it to the United States reduce harms directly associated with injection drug use, but they also appear to decrease the risk of mortality from any cause, results of a new cohort study from Canada suggest. The study title is Supervised injection facility use and all‐cause mortality among people who inject drugs in Vancouver, Canada: A cohort study and the authors are Mary Clare Kennedy and colleagues.

Supervised injection facility use and all-cause mortality among people who inject drugs in Vancouver, Canada: A cohort study.

BackgroundPeople who inject drugs (PWID) experience elevated rates of premature mortality. Although previous studies have demonstrated the role of supervised injection facilities (SIFs) in reducing various harms associated with injection drug use, including accidental overdose death, the possible impact of SIF use on all-cause mortality is unknown. Therefore, we examined the relationship between frequent SIF use and all-cause mortality among PWID in Vancouver, Canada.Methods and findingsData were derived from 2 prospective cohort studies of PWID in Vancouver, Canada, between December 2006 and June 2017. Every 6 months, participants completed questionnaires that elicited information regarding sociodemographic characteristics, substance use patterns, social-structural exposures, and use of health services including SIFs. These data were confidentially linked to the provincial vital statistics database to ascertain mortality rates and causes of death. We used multivariable extended Cox regression analyses to estimate the independent association between frequent (i.e., at least weekly) SIF use and all-cause mortality. Of 811 participants, 278 (34.3%) were women, and the median age was 39 years (IQR 33–46) at baseline. In total, 432 (53.3%) participants reported frequent SIF use at baseline, and 379 (46.7%) did not. At baseline, frequent SIF users were on average younger than nonfrequent users, and a higher proportion of frequent SIF users than nonfrequent users were unstably housed, resided in the Downtown Eastside neighbourhood, injected in public, had a recent non-fatal overdose, used prescription opioids at least daily, injected heroin at least daily, injected cocaine at least daily, and injected crystal methamphetamine at least daily. A lower proportion of frequent SIF users than nonfrequent users were HIV positive and enrolled in addiction treatment at baseline. The median duration of follow-up among study participants was 72 months (IQR 24–123). In total, 112 participants (13.8%) died during the study period, yielding a crude mortality rate of 22.7 (95% CI 18.7–27.4) deaths per 1,000 person-years. The median years of potential life lost per death was 34 (IQR 27–42) years. In a time-updated multivariable model, frequent SIF use was inversely associated with risk of all-cause mortality after adjusting for potential confounders, including age, sex, HIV seropositivity, unstable housing, at least daily cocaine injection, public injection, incarceration, enrolment in addiction treatment, and calendar year of interview (adjusted hazard ratio 0.46, 95% CI 0.26–0.80, p = 0.006). The main study limitations are the limited generalizability of findings due to non-random sampling, the potential for reporting biases due to reliance on some self-reported information, and the possibility that residual confounding influenced findings.ConclusionsWe observed a high burden of premature mortality among a community-recruited cohort of PWID. Frequent SIF use was associated with a lower risk of death, independent of relevant confounders. These findings support efforts to enhance access to SIFs as a strategy to reduce mortality among PWID. Further analyses of individual-level data are needed to determine estimates of, and potential causal pathways underlying, associations between SIF use and specific causes of death.

Moving into an urban drug scene among people who use drugs in Vancouver, Canada: Latent class growth analysis.

BackgroundUrban drug scenes are characterized by high prevalence of illicit drug dealing and use, violence and poverty, much of which is driven by the criminalization of people who use illicit drugs (PWUD) and the associated stigma. Despite significant public health needs, little is understood about patterns of moving into urban drug scenes among PWUD. Therefore, we sought to identify trajectories of residential mobility (hereafter ‘mobility’) among PWUD into the Downtown Eastside (DTES), an urban neighbourhood with an open drug scene in Vancouver, Canada, as well as characterize distinct trajectory groups among PWUD.MethodsData were derived from three prospective cohort studies of community-recruited PWUD in Vancouver between 2005 and 2016. We used latent class growth analysis (LCGA) to identify distinct patterns of moving into the DTES among participants residing outside of DTES at baseline. Multivariable multinomial logistic regression was used to determine baseline factors associated with each trajectory group.ResultsIn total, 906 eligible participants (30.9% females) provided 9,317 observations. The LCGA assigned four trajectories: consistently living outside of DTES (52.8%); early move into DTES (11.9%); gradual move into DTES (19.5%); and move in then out (15.8%). Younger PWUD, those of Indigenous ancestry, those who were homeless or living in a single-room occupancy hotel (SRO), and those injecting drugs daily were more likely to move in then out of DTES (all p<0.05). Living in an SRO, daily injection drug use, and recent incarceration were also positively associated with early mobility (all p<0.05).ConclusionsNearly half of the participants moved into the DTES. Younger PWUD and Indigenous peoples appeared to have particularly high mobility, as did those with markers of social-structural vulnerability and high intensity drug use. These findings indicate a need to tailor existing social and health services within the DTES and expand affordable housing options outside the DTES.

Willingness to take buprenorphine/naloxone among people who use opioids in Vancouver, Canada

ObjectivesOpioid agonist therapy is the cornerstone of treatment of opioid use disorder. In Canada, buprenorphine/naloxone has recently been adopted as the first line agonist therapy given its comparable effectiveness to methadone and superior safety profile. This study examines factors associated with willingness to take buprenorphine/naloxone among opioid users. MethodsData were derived from two prospective cohorts of high-risk individuals who use drugs in Vancouver, Canada. Multivariable logistic regression analyses were used to determine factors associated with willingness to use buprenorphine/naloxone among people who use opioids and were not currently accessing this treatment option. Participants who were unwilling to use buprenorphine/naloxone were invited to provide reason(s) and their responses were examined in a sub-analysis. ResultsBetween December 2014 and May 2018, 1103 participants were interviewed. Overall, 194 (17.6%) respondents indicated that they would be willing to take buprenorphine/naloxone. Variables independently associated with willingness were previous buprenorphine/naloxone treatment (adjusted odds ratio [AOR] = 2.04), having ever used methadone treatment (AOR = 1.87), and age (AOR = 0.98, per year older) (all p < 0.05). Satisfaction with current agonist therapy (25.4%), not knowing what buprenorphine/naloxone is (25.1%), and wanting more information about buprenorphine/naloxone (15.1%) were the most commonly cited reasons for unwillingness. A low rate of willingness to use buprenorphine/naloxone (15.1%) was also observed among the sub-set of participants not using methadone. ConclusionsWhile an overall low level of willingness to take buprenorphine/naloxone was observed, this appeared to be largely driven by satisfaction with other agonists and a low prevalence of community knowledge about buprenorphine/naloxone.

Longitudinal migration patterns from an open illicit drug scene among people who use illicit drugs in Vancouver, Canada

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.