An age-based analysis of nonmedical prescription opioid use among people who use illegal drugs in Vancouver, Canada

Receipt of COVID-19 emergency funds and engagement in sex work during COVID-19 among people who use drugs: evidence from Vancouver, Canada

BACKGROUND

During the early period of the COVID-19 pandemic, public health orders disrupted income generation in numerous sectors and many governments provided emergency financial support. Access to government support and changes in engagement in sex work during the early period of the pandemic among people who use drugs (PWUD) are not well described. In the present study, we investigate the prevalence and correlates of engaging in sex work during the COVID-19 pandemic, among PWUD in Vancouver, Canada.

METHODS

Data derived from three harmonized cohorts of PWUD. Using multivariable logistic regression, we characterized factors associated with engaging in sex work in the last month between July 17 and November 30, 2020. Reports of changes in frequency of engagement in sex work since the pandemic were also collected.

RESULTS

Of the 864 individuals included in this analysis, 55 (6.4%) reported sex work engagement in the last month. Among these participants, 40.7% reported receiving COVID-19 income support in the past month vs. 52.7% of the rest of the sample, though receipt of income support in the past six months was similar between the two groups (72.2% vs. 75.7%, p = 0.624). In multivariable analysis, receipt of financial support in the last month was negatively associated with engagement in sex work in the last month (adjusted odds ratio [AOR] = 0.44 [95% confidence interval [CI]: 0.24-0.81]). Among 69 participants who responded to a question regarding changes in engagement in sex work, 38 (55.1%) reported a decrease, 11 (15.9%) reported an increase, 19 (27.5%) reported no change, and 1 (1.4%) reported cessation.

CONCLUSIONS

Findings document that engagement in sex work appears to have declined early in the pandemic. Participants who received income support in the past month were less likely to report recent engagement in sex work. Findings suggest that recent receipt of income support may have contributed to reductions in engagement in sex work. Additional investigation is warranted.

Characterizing Use of Supervised Consumption Services among Street-involved Youth and Young Adults in the Context of an Overdose Crisis

In response to an increase in overdose deaths, there was a rapid scale-up of supervised consumption services (SCS), including federally sanctioned SCS and low-barrier SCS known as overdose prevention sites (OPS), in Vancouver, Canada, beginning in December 2016. However, little is known about the use of such services among adolescents and young adults (AYA) in this context. We therefore sought to characterize factors associated with the use of federally sanctioned SCS and OPS among street-involved AYA who inject drugs in Vancouver during an overdose crisis. From December 2016 to March 2020, data were collected from a prospective cohort of street-involved AYA aged 14 to 26 at baseline. Using multivariable generalized estimating equation analyses, we identified factors associated with recent use of federally sanctioned SCS and OPS, respectively. Among 298 AYA who inject drugs, 172 (57.8%) and 149 (50.0%) reported using federally sanctioned SCS and OPS during the study period, respectively. In multivariable analyses, public injecting, negative police interactions, and residing or spending time ≥ weekly in the Downtown Eastside neighborhood were all positively associated with the use of federally sanctioned SCS and OPS, respectively. Additionally, ≥ daily unregulated opioid use and residential eviction were positively associated with federally sanctioned SCS use, while requiring help injecting was inversely associated. Self-identified female or non-binary gender was also positively associated with OPS use (all p < 0.05). Both federally sanctioned SCS and OPS successfully engaged AYA at heightened risk of adverse health outcomes. However, the lack of accommodation of AYA who require manual assistance with injecting at federally sanctioned SCS may be inhibiting service engagement.

Polypharmacy and Healthcare Service Use Among Prescription Opioid Poisoning Cases Age 50

Objectives: To examine relationships between polypharmacy and level of healthcare service use among prescription opioid poisoning cases age 50 and older. Methods: Data came from the American Association of Poison Control Center's National Poison Data System, 2015-2020. We used multinomial logistic regression to examine the study questions. Results: Of the 77 946 cases with prescription opioid exposures, 64.5% were managed at a healthcare facility (HCF). Of HCF-managed cases, 41.2% were treated/evaluated and released and 21.3% and 37.5% were admitted for noncritical care and critical care, respectively. Medications for cardiovascular disease, benzodiazepines, other types of sedatives/hypnotics, antipsychotics, muscle relaxants, acetaminophen, and gabapentin were associated with increased risk of admission to both noncritical and critical care compared to treatment/evaluation and release. Acetaminophen use had the highest relative risk ratios (RRRs) for noncritical care (1.70, 95% CI = 1.51-1.91) and critical care (1.56, 95% CI = 1.39-1.76). Each additional medication/substance used was associated with 1.14 (95% CI = 1.11-1.17) and 1.19 (95% CI = 1.16-1.22) greater risk of noncritical and critical care admissions, respectively. Conclusions: Among older-adult poison control center cases for prescription opioid exposures, co-use of several commonly prescribed/used medicines was associated with increased risk of admissions to both noncritical and critical care units. Careful monitoring of medication use among older adults who use prescription opioids may reduce the risk of unintentional and intentional opioid poisoning.

Interest in using buprenorphine-naloxone among a prospective cohort of street-involved young people in Vancouver, Canada

INTRODUCTION

Limited research examines buprenorphine-naloxone interest among adolescents and young adults (AYA). This longitudinal study examined factors associated with initial buprenorphine-naloxone interest and the time to a positive change in buprenorphine-naloxone interest or enrollment, in addition to identifying reasons for buprenorphine-naloxone disinterest.

METHODS

The study derived data from a cohort of street-involved AYA in Vancouver, Canada between December 2014 and June 2018. The analysis was restricted to AYA who reported weekly or daily illicit opioid use in the last six months but had not initiated buprenorphine-naloxone. The study examined factors associated with initial buprenorphine-naloxone interest using multivariable logistic regression, while multivariable Cox regression identified factors associated with the time to a positive change in buprenorphine-naloxone interest or actual enrollment over follow-up among AYA initially disinterested in buprenorphine-naloxone.

RESULTS

Of 281 participants who reported weekly illicit opioid use but were not on buprenorphine-naloxone, 52 (18.5 %) AYA reported initial buprenorphine-naloxone interest, while 68 (24.2 %) AYA who were initially disinterested in buprenorphine-naloxone reported interest or enrollment over follow-up. In multivariable logistic regression, initial interest was positively associated with older age (Adjusted Odds Ratio [AOR] = 1.09, 95 % Confidence Interval [CI]: 1.03-1.15), but negatively associated with self-reported Indigenous identity (AOR = 0.22, 95 % CI: 0.07-0.68). In multivariable Cox regression, recent detoxification program access (Adjusted Hazard Ratio [AHR] = 0.85, 95 % CI: 0.73-0.98) was positively associated with the time to a positive change in buprenorphine-naloxone interest or enrollment. Common reasons for buprenorphine-naloxone disinterest included not wanting opioid agonist treatments (OAT) (initial n = 67, follow-up n = 105); not wanting to experience precipitated withdrawal (initial n = 42, follow-up n = 54), being satisfied with or preferring other OAT (initial n = 33, follow-up n = 52), not knowing what buprenorphine-naloxone is (initial n = 27, follow-up n = 9), previous negative treatment experiences (initial n = 19, follow-up n = 20), and wanting to continue opioid use (initial n = 13, follow-up n = 9), among others.

CONCLUSIONS

We documented persistent disinterest in buprenorphine-naloxone among AYA, though participants' reasons for disinterest provide insight into the potential benefits of expanding micro-dosing induction; ensuring treatment is culturally safe; and communicating changes in buprenorphine-naloxone programming to AYA. Nevertheless, a need remains to improve the continuum of harm reduction and treatment supports for AYA.

Methadone Maintenance Treatment Discontinuation Among Young People who use Opioids in Vancouver, Canada

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.

Increasing preference for fentanyl among a cohort of people who use opioids in Vancouver, Canada, 2017-2018

Background: Despite increasing prevalence of illicit fentanyl use in the US and Canada, preference for fentanyl over other illicit opioids has not been fully characterized. Therefore, we sought to describe changes in illicit opioid preferences over time among people who inject drugs (PWID). Methods: Data were obtained from two prospective cohort studies between 2017 and 2018. Trends in opioid preference over time were examined using bivariable generalized estimating equation (GEE) analysis. Multivariable models were used to identify factors associated with fentanyl preference. Results: Among 732 eligible participants, including 425 (58%) males, the prevalence of preference for fentanyl increased from 4.4% in 2017 to 6.6% in 2018 (Odds Ratio [OR] = 1.27, 95% Confidence Interval [CI]: 1.05-1.52). In a multivariable analysis, younger age (Adjusted Odds Ratio [AOR] = 0.94, 95% CI: 0.92-0.96) and daily crystal methamphetamine injection (AOR = 1.68, 95% CI: 1.01-2.78) were independently associated with preference for fentanyl. The most common reasons for preferring fentanyl included "better high than other opioids" (45%), and "lasts longer than heroin" (27%). Conclusions: The current study has demonstrated that preference for fentanyl has been increasing over time among our sample of PWID who use opioids. Further work is needed to clarify risk factors surrounding transitions to illicit fentanyl.

Housing, opportunities, motivation and engagement (HOME) for homeless youth at-risk for opioid use disorder: study protocol for a randomized controlled trial

Background

Homeless youth experience high rates of substance use disorders, exposures to violence, mental and physical health conditions, and mortality. They have been particularly affected by the opioid crisis. However, no study to date has used a randomized controlled design to test preventive interventions of opioid and other drug use among this vulnerable population. Resolution of youth homelessness through housing and supportive services including prevention services, often referred to as “Housing First,” has great potential to reduce the likelihood for the development of an opioid use disorder as well as other problem behaviors associated with living on the streets. Housing First has been tested through randomized trials among homeless adults with mental health and substance use disorders, but has not been empirically tested for opioid prevention among homeless youth.

Methods

Homeless youth will be recruited from a drop-in shelter site frequented by disconnected youth; they will be screened for eligibility, including current homelessness, age 18–24 years, and not currently meeting criteria for opioid use disorder (OUD). In a controlled trial, 240 youth will then be randomized to one of two conditions, (1) housing + opioid and related risk prevention services, or (2) opioid and related risk prevention services alone. This project utilizes existing efficacious models of prevention to address opioid-related risks, including motivational interviewing, strengths-based outreach and advocacy, and an HIV risk preventive intervention. Follow-up will be conducted at 3, 6, 9 and 12-months post-baseline. The economic cost of each intervention will be determined to support implementation decisions with other providers and their funders.

Discussion

This study will provide essential information for researchers and providers on the efficacy of housing + opioid and related risk prevention services in an RCT for effects on opioid use and mechanisms underlying change. Because youth experiencing homelessness are at increased risk for a variety of adverse outcomes, the proposed intervention may produce substantial health care benefits to the youths and society at large.

Trial registration ClinicalTrials.gov, NCT04135703, Registered October 13, 2019, https://clinicaltrials.gov/ct2/show/NCT04135703?term=NCT04135703&draw=2&rank=1#contacts

Prescription medication use among Canadian children and youth, 2012 to 2017

BACKGROUND

Prescription medications are used throughout the life course, including among children and youth. Prescribing practices may be influenced by emerging medical conditions, the availability of new medications, changing clinical practices, and evolving knowledge of the safety and effectiveness of medications. The Canadian Health Measures Survey (CHMS) provides national-level information to help monitor the use of prescribed medications in the population.

DATA AND METHODS

Based on data from the CHMS (2012 to 2017), this article describes prescription medication use in the past month among those aged 3 to 19 years. Information on up to 45 prescription medications was recorded and classified according to Health Canada's Anatomical Therapeutic Chemical classification. Frequencies and bivariate analyses examined medication use by sociodemographic and health-related factors. The most common medication classes were identified for each age group.

RESULTS

An estimated 23% of Canadian children and youth (1.5 million) had used at least one prescription medication in the past month and 9% had used two or more prescription medications.Prescription medication use was more common among those who reported lower levels of general and mental health, as well as among those with asthma (51%), a mood disorder (71%), attention deficit disorder (60%) or a learning disability (43%). Medications for the respiratory and nervous systems were among those most commonly prescribed. Of youth aged 14 years or older, 4% had misused prescription medications for non-medicinal purposes, for the experience, for the feeling they cause or to get high.

DISCUSSION

Prescription medication use among children and youth is common in Canada. It is associated with lower levels of self-reported health and the presence of chronic conditions. The estimates provide a benchmark to help monitor prescription drug use in Canada.

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

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.

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

BACKGROUND

As 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).

METHODS

We 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.

RESULTS

Acceptability 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.

CONCLUSIONS

Our findings suggest improvements in care and improved patient-provider relationships would increase the acceptability of a potential HIV vaccine among this population.

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

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.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.