Public Policy, School of

Receive updates for this collection

Patterns of Non-injection Drug Use Associated with Injection Cessation among Street-Involved Youth in Vancouver, Canada

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2018-01-16
Abstract: 

Although abstinence from drug use is often a key goal of youth substance use treatment, transitioning to less harmful routes and types of drug use is desirable from both a clinical and public health perspective. Despite this, little is known about the trajectories of youth who inject drugs including changes in patterns of non-injection drug use. The At-Risk Youth Study (ARYS) is a longitudinal cohort of street-involved youth who use drugs in Vancouver, Canada. We used linear growth curve modeling to compare changes in non-injection drug use among participants who ceased injecting drugs for at least one 6-month period between September 2005 and May 2015 to matched controls who continued injecting over the same period. Of 387 eligible participants, 173 (44.7%) reported ceasing drug injection at least once. Non-injection drug use occurred during 160 (79.6%) periods of injection cessation. In adjusted linear growth curve analyses, the only non-injection drug use pattern observed to decrease significantly more than controls following injection cessation was daily crack/cocaine use (p = 0.024). With the exception of frequent crack/cocaine use, transitions out of injection drug use did not appear to coincide with increased reductions in patterns of non-injection drug use. Our findings indicate that most (80%) of the observed injection cessation events occurred in the context of ongoing substance use. Given that transitioning out of drug injection represents a significant reduction in risk and harm, efforts supporting vulnerable youth to move away from injecting may benefit from approaches that allow for ongoing non-injection drug use.

 

Document type: 
Article

Nonmedical Prescription Opioid Use and Illegal Drug Use: Initiation Trajectory and Related Risks Among People Who Use Illegal Drugs in Vancouver, Canada

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2018-01-16
Abstract: 

Objective: We investigated the prevalence of and risk factors associated with initiating nonmedical prescription opioid use (NMPOU) before and after illegal drugs using data from two linked cohort studies of street youth and adults who use illegal drugs in Vancouver, Canada. All participants who attended a study visit between 2013-2016 were eligible for the primary analyses.

Results: Among 512 youth and 833 adult participants, the prevalence of NMPOU was extremely high (88% among street youth; 90% among adults), and over one-third of those who reported engaging in NMPOU had initiated NMPOU before illegal drug use (vs. transitioning from illegal drugs to NMPOU). Participants who reported either transitioning to or from NMPOU had higher risk profiles, particularly related to substance use, when compared with those who reported never engaging in NMPOU. Sub-analyses restricted to only those who engaged in NMPOU found few statistically significant differences between those who initiated NMPOU prior to illegal drugs versus those who initiated illegal drugs prior to NMPOU. Findings suggest that among people who use illegal drugs, early NMPOU trajectories do not appear to critically shape future patterns and practices.

Document type: 
Article

Increasing Availability of Illicit and Prescription Opioids among People who Inject Drugs in a Canadian Setting, 2010-2014

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2017-10
Abstract: 

Background: The increase over the past decade in the non-medical use of prescription opioids and illicit opioids in North America has resulted in significant health-related harms.Objective: We sought to examine temporal trends and correlates of the availability of illicit and prescription opioids among people who inject drugs (PWID) in Vancouver, Canada.Methods: Data were derived from three prospective cohort studies of PWID in Vancouver between 2010 and 2014. In semiannual interviews, participants reported the availability of five sets of illicit and prescription opioids: (1) heroin; (2) Percocet (oxycodone/acetaminophen), Vicodin (hydrocodone/acetaminophen) or Demerol (meperidine); (3) Dilaudid (hydromorphone); (4) Morphine; (5) oxycontin/OxyNEO (controlled-release oxycodone). We defined perceived availability as immediate (e.g., available within 10 minutes) vs. no availability/available after 10 minutes. The trend and correlation of immediate availability were identified by multivariable generalized estimating equations logistic regression.Results: Among 1584 participants, of which 564 (35.6%) were female, the immediate availability of all illicit and prescribed opioids (except for oxycontin/OxyNEO) increased over time, independent of potential confounders. The Adjusted Odds Ratios of immediate availability associated with every calendar year increase were between 1.09 (95% confidence interval 1.05-1.12) (morphine and Dilaudid) and 1.13 (95% confidence interval 1.09-1.17) (Percocet/Vicodin/Demerol) (all p-values <0.05).Conclusion: The availability of most prescription opioids had continued to increase in recent years among our sample of PWID in Vancouver. Concurrent increases in the availability of heroin were also observed, raising concerns regarding combination of both illicit and prescription opioids use among PWID that could potentially increase the risk of overdose.

Document type: 
Article

Between a Rock and a Hard Place: Prescription Opioid Restrictions in the Time of Fentanyl and Other Street Drug Adulterants

Author: 
Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2017-09
Abstract: 

Non-medical prescription opioid use (NMPOU) has increased alarmingly across Canada and resulted in strict prescribing restrictions on opioids. Despite a clear need to reduce opioid prescriptions in response to this crisis, few other policies have been implemented and this singular focus is incongruent with the known characteristics of substance use disorders, negative effects of supply reduction policies, and realities of pain management. Given the recent rise of fentanyl and other dangerous adulterants in street drugs, this commentary argues that a comprehensive response to NMPOU that includes improvements to addiction management and harm-reduction services is urgently needed.

Document type: 
Article
File(s): 

High School Incompletion and Childhood Maltreatment among Street-Involved Young People in Vancouver, Canada

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2015-12
Abstract: 

While the link between educational attainment and future health and wellness is well understood, little investigation has considered the potential impacts of distinct forms of childhood maltreatment on high school completion. In the present study, the relationship between five categories of childhood maltreatment (physical, emotional, and sexual abuse, and physical and emotional neglect) and completion of high school education were examined using the Childhood Trauma Questionnaire (CTQ). From September 2005 to May 2013, data were collected for the At-Risk Youth Study (ARYS), a cohort of street-involved young people who use illicit drugs in Vancouver, Canada. We used logistic regression to examine the relationship between childhood maltreatment and high school completion, while controlling for a range of potential confounding variables. Specifically, five separate models for each category of maltreatment and two combined models were employed to examine the relative associations between, and cumulative impact of, different forms of childhood maltreatment and educational attainment. Among 974 young people, 737 (76%) reported not completing high school. In separate multivariable analyses physical abuse, emotional abuse, physical neglect, and emotional neglect remained positively and independently associated with an incomplete high school education. In a combined multivariable model with all forms of childhood maltreatment considered together, emotional abuse (Adjusted Odds Ratio=2.08; 95% Confidence Interval: 1.51-2.86) was the only form of maltreatment that remained significantly associated with an incomplete high school education. The cumulative impact assessment indicated a moderate dose-dependent trend where the greater the number of different forms of childhood maltreatment the greater the risk of not completing a high school education. These findings point to the need for trauma informed interventions to improve educational attainment among vulnerable young people, as well as evidence-based prevention programmes, such as the Nurse-Family Partnership, aimed at supporting at-risk families before maltreatment occurs.

Document type: 
Article
File(s): 

Still "At Risk": An Examination of How Street-Involved Young People Understand, Experience, and Engage With "Harm Reduction" in Vancouver's Inner City

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2017-06
Abstract: 

Background: Vancouver is an international leader in implementing interventions to reduce harms related to drug use. However, street-involved young people who use drugs continue to be vulnerable to overdose death, hepatitis C (HCV) infection, and high rates of syringe sharing. In order to understand why young people in this setting continue to experience drug related harms despite an intensive public health response, we examined how young people understood, experienced and engaged with harm reduction in the context of drug scene involvement and marginalization.Methods: Twelve semi-structured interviews were conducted in 2013 with thirteen young people (ages 17-28) recruited from the At-Risk Youth Study, a prospective cohort of street-involved and drug-using young people. These interviews were embedded within a larger, eight-year program of ethnographic research and explored participants' understandings of harm reduction, their use of specific services, and their ideas about improving their day-to-day lives. Interviews were transcribed verbatim and a thematic analysis was performed.Results: Young peoples’ understandings of and ideas about harm reduction were diverse and expansive. Many young people articulated the limitations of existing programs, indicating that while they are positioned to reduce the risk of HIV and HCV transmission, they offer little meaningful support to improve young peoples’ broader life chances. Young people described strategies to mitigate risk and harm in their own lives, including transitioning to drugs deemed less harmful and attempts to access addiction treatment. Finally, young people indicated that spatial considerations (e.g., distance from Vancouver's Downtown Eastside) strongly determined access to services.Conclusions: In Vancouver, a large, well established harm reduction infrastructure seeks to reduce HIV and HCV transmission among street-involved young people. However, young peoples’ multiple understandings, experiences and engagements with harm reduction in this setting illustrate the limitations of the existing infrastructure in improving their broader life chances.

Document type: 
Article

The Association Between Residential Eviction and Syringe Sharing Among a Prospective Cohort of Street-Involved Youth

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2017-08-02
Abstract: 

Background: Syringe sharing is a high-risk practice associated with the transmission of infectious diseases, such as HIV and HCV. While youth who contend with housing instability are known to be more likely to engage in high risk substance use, the potential relationship between being evicted from housing and syringe sharing has not been examined. This study assessed whether residential eviction was associated with syringe sharing among street-involved youth in Vancouver, Canada.

Methods: Data were derived from the At-Risk Youth Study (ARYS), a prospective cohort of street-involved youth who use drugs age 14-26 in Vancouver, Canada. The study period was June 2007 to May 2014 and the potential relationship between residential eviction and syringe sharing was analyzed using multivariable generalized estimating equations (GEE) logistic regression.

Results: Among 405 street-involved youth who injected drugs, 149 (36.8%) reported syringe sharing, defined as borrowing or lending a syringe, at some point during the study period. In a multivariable GEE analysis, recent residential eviction remained independently associated with syringe sharing (Adjusted Odds Ratio [AOR] = 1.72, 95% Confidence Interval [CI]: 1.16–2.57), after adjusting for potential confounders.

Conclusions: Syringe sharing was significantly elevated among youth who had recently been evicted from housing. These findings indicate that policy and programmatic interventions that increase housing stability may help mitigate high risk substance use practices among vulnerable youth.

Document type: 
Article

Knowledge of Hepatitis C and Treatment Willingness Amongst People Who Inject Drugs in an Era of Direct Acting Antivirals

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2017-07-27
Abstract: 

Background: Knowledge of hepatitis C virus (HCV) is believed to be important in altering risk behaviour, improving engagement in care, and promoting willingness to initiate HCV treatment. We assessed factors associated with HCV knowledge and treatment willingness amongst people who inject drugs (PWID) in an era of direct acting antivirals.

Methods: Data were derived from three prospective cohort studies of PWID in Vancouver, Canada, between June 2014 and May 2015. HCV knowledge and treatment willingness were assessed using a Likert scale. Multivariable linear regression identified factors associated with higher HCV knowledge and treatment willingness.

Results: Amongst 630 participants, mean scores for HCV knowledge and treatment willingness were 25.41 (standard deviation [SD]: 2.52) out of 30, and 6.83 (SD: 1.83) out of 10, respectively. In multivariable analyses, Caucasian ancestry (adjusted linear regression model estimate [β] 0.50; 95% confidence interval [CI] 0.17, 0.82), employment (β 0.76; 95% CI: 0.38, 1.13), diagnosed mental health disorder (β 0.44; 95% CI: 0.11, 0.78) and previous HCV treatment (β 0.94; 95% CI: 0.46, 1.43) were independently associated with higher knowledge. Downtown Eastside (DTES) residence (i.e., epicenter of Vancouver’s drug scene) was independently associated with lower knowledge (β -0.48; 95% CI: -0.81, -0.15). Greater HCV knowledge (β 0.12; 95% CI: 0.07, 0.17) was independently associated with higher HCV treatment willingness. DTES residence (β -0.31; 95% CI: -0.56, -0.06) and daily crack cocaine smoking (β -0.52; 95% CI: -0.92, -0.13) were independently associated with lower treatment willingness.

Conclusion: Socioeconomic factors, such as neighborhood residence and employment, were associated with HCV knowledge. Higher HCV knowledge was associated with more HCV treatment willingness. Our findings suggest that increasing HCV knowledge amongst PWID may be an integral component of the HCV cascade of care and that efforts might be best targeted to individuals with greater socioeconomic disadvantage.

Document type: 
Article
File(s): 

Increasing Availability of Benzodiazepines Among People Who Inject Drugs in a Canadian Setting

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2017-07-27
Abstract: 

Background: Benzodiazepine misuse is associated with mortality and is common among people who inject drugs (PWID). This study aimed to examine the temporal trends in the availability of benzodiazepines among PWID in a Canadian setting, and to identify factors associated with more immediate access to benzodiazepines.

Methods: Data were derived from three prospective cohorts of PWID in Vancouver, Canada, between June 2012 and May 2015. The primary outcome was the perceived availability of benzodiazepines, measured in three levels: not available, delayed availability (available in ≥10 min), and immediate availability (available in <10 min). We used multivariable generalized estimating equations to identify factors associated with availability of benzodiazepines.

Results: In total, 1641 individuals were included in these analyses. In multivariable analyses, factors associated with immediate benzodiazepine availability included incarceration (adjusted odds ratio (AOR): 1.42, 95% CI1.06, 1.89) and participation in methadone maintenance therapy (MMT) (AOR: 1.35, 95% CI 1.14, 1.60). Factors associated with delayed benzodiazepine availability included incarceration (AOR: 1.45, 95% CI 1.02, 2.07) and MMT (AOR: 1.77, 95% CI 1.48, 2.12). Benzodiazepine availability increased throughout the study period for both immediate (AOR: 1.14, 95% CI 1.10, 1.18 per 6-month follow-up period) and delayed availability (AOR: 1.17, 95% CI 1.12, 1.22 per 6-month follow-up period).

Conclusions: Among our sample of PWID, benzodiazepine availability is increasing and was associated with health and criminal justice system characteristics. Our findings indicate a need to examine prescribing practices and educate both PWID and healthcare providers about the risks associated with benzodiazepine use.

Document type: 
Article

Intentional Cannabis Use to Reduce Crack Cocaine Use in a Canadian Setting: A Longitudinal Analysis

Peer reviewed: 
Yes, item is peer reviewed.
Date created: 
2017-07-25
Abstract: 

Background: No effective pharmacotherapies exist for the treatment of crack cocaine use disorders. Emerging data suggests that cannabinoids may play a role in reducing cocaine related craving symptoms. This study investigated the intentional use of cannabis to reduce crack use among people who use illicit drugs (PWUD).

Methods: Data were drawn from three prospective cohorts of PWUD in Vancouver, Canada. Using data from participants reporting intentional cannabis use to control crack use, we used generalized linear mixed-effects modeling to estimate the independent effect of three predefined intentional cannabis use periods (i.e., before, during and after first reported intentional use to reduce crack use) on frequency of crack use.

Results: Between 2012 and 2015, 122 participants reported using cannabis to reduce crack use, contributing a total of 620 observations. In adjusted analyses, compared to before periods, after periods were associated with reduced frequency of crack use (Adjusted Odds Ratio [AOR] = 1.89, 95% Confidence Interval [CI]: 1.02–3.45), but not the intentional use periods (AOR= 0.85, 95% CI: 0.51–1.41). Frequency of cannabis use in after periods was higher than in before periods (AOR = 4.72, 95% CI: 2.47–8.99), and showed a tendency to lower frequency than in intentional cannabis use periods (AOR = 0.56, 95% CI: 0.32–1.01).

Conclusions: A period of intentional cannabis use to reduce crack use was associated with decreased frequency of crack use in subsequent periods among PWUD. Further clinical research to assess the potential of cannabinoids for the treatment of crack use disorders is warranted.

Document type: 
Article