Estimating the total utilization of take home naloxone during an unregulated drug toxicity crisis: A Bayesian modeling approach

BACKGROUND

British Columbia (BC) Canada has a large take-home naloxone (THN) program, implemented as part of the provincial response to the ongoing toxic unregulated drug supply emergency. Ascertaining the rate of use of THN kits is vital to understanding the full impact of the program. However, this is a challenging problem due to under-reporting of kit distribution. This study aims to estimate the total number of THN kits used based on the number of THN kits shipped, the number of THN kits reported as distributed, and the number of THN kits reported as used.

METHODS

We used BC THN shipment and distribution records (February 2015 to August 2023) to inform a simple Bayesian model of naloxone kit distribution and use. A logistic regression term by health region and distribution site type was incorporated to account for variable under-reporting, and a convolution term was incorporated to account for kit distribution.

RESULTS

We find the number of THN kits reported as used, and the number of total THN kits distributed, are largely under-reported. An estimated 1,500 (95 % CrI: 1,430 - 1,590) THN kits per 10,000 BC population were used, of which 288 per 10,000 had been reported as used. Of all the THN kits shipped, the model estimated that 43 % (95 % CrI: 41-45 %) of kits were used. We also found variation in both distribution and use by distribution site type, with kits distributed from overdose prevention sites having the highest rate of use (56 %; 95 % CrI: 53-59 %).

CONCLUSION

Across all sites, kit use is approximately five times higher than has been reported. Our framework can also be applied to other localities where THN programs operate, in order to better estimate the true reach and impact of take home naloxone distribution.

Physiologic oxygen responses to smoking opioids: an observational study using continuous pulse oximetry at overdose prevention services in British Columbia, Canada

BACKGROUND

In British Columbia, Canada, smoking is the most common modality of drug use among people who die of opioid toxicity. We aimed to assess oxygen saturation (SpO2) while people smoked opioids during a pilot study that introduced continuous pulse oximetry at overdose prevention services (OPS) sites.

METHODS

This was an observational cohort study, using a participatory design. We implemented our monitoring protocol from March to August 2021 at four OPS. We included adults (≥ 18 years) presenting to smoke opioids. A sensor taped to participants' fingers transmitted real-time SpO2 readings to a remote monitor viewed by OPS staff. Peer researchers collected baseline data and observed the timing of participants' inhalations. We analyzed SpO2 on a per-event basis. In mixed-effects logistic regression models, drop in minimum SpO2 ≤ 90% in the current minute was our main outcome variable. Inhalation in that same minute was our main predictor. We also examined inhalation in the previous minute, cumulative inhalations, inhalation rate, demographics, co-morbidities, and substance use variables.

RESULTS

We recorded 599 smoking events; 72.8% (436/599) had analyzable SpO2 data. Participants' mean age was 38.6 years (SD 11.3 years) and 73.1% were male. SpO2 was highly variable within and between individuals. Drop in SpO2 ≤ 90% was not significantly associated with inhalation in that same minute (OR: 1.2 [0.8-1.78], p = 0.261) or inhalation rate (OR 0.47 [0.20-1.10], p = 0.082). There was an association of SpO2 drop with six cumulative inhalations (OR 3.38 [1.04-11.03], p = 0.043); this was not maintained ≥ 7 inhalations. Demographics, co-morbidities, and drug use variables were non-contributory.

CONCLUSIONS

Continuous pulse oximetry SpO2 monitoring is a safe adjunct to monitoring people who smoke opioids at OPS. Our data reflect challenges of real-world monitoring, indicating that greater supports are needed for frontline responders at OPS. Inconsistent association between inhalations and SpO2 suggests that complex factors (e.g., inhalation depth/duration, opioid tolerance, drug use setting) contribute to hypoxemia and overdose risk while people smoke opioids.

What features of drug treatment programs help, or not, with access? a qualitative study of the perspectives of family members and community-based organization staff in Atlantic Canada

BACKGROUND

Withdrawal management and opioid agonist treatment (OAT) programs help to reduce some of the harms experienced by people who use substances (PWUS). There is literature on how features of drug treatment programs (e.g., policies and practices) are helpful, or not helpful, to PWUS when seeking access to, or in, treatment. There is, however, relatively little literature based on the perspectives of family members/family of choice of PWUS and community-based organization staff within the context of Atlantic Canada. This paper explored the perspectives of these two groups on what was helpful, or not, about drug treatment programs in Atlantic Canada in terms of supporting access to, and retention in, treatment.

METHODS

One-on-one qualitative telephone interviews were conducted in 2020 with the two groups. Interviews focused on government-funded withdrawal management and OAT programs. Data were coded using a qualitative data management program (ATLAS.ti) and analyzed inductively for key themes/subthemes using grounded theory techniques.

RESULTS

Fifteen family members/family of choice and 16 community-based organization staff members participated (n = 31). Participants spoke about features of drug treatment programs in various places, and noted features that were perceived as helpful (e.g., quick access), as well as not helpful (e.g., wait times, programs located far from where PWUS live). Some participants provided their perceptions of how PWUS felt when seeking or accessing treatment. A number of participants reported taking various actions to help support access to treatment, including providing transportation to programs. A few participants also provided suggestions for change to help support access and retention such as better alignment of mental health and addiction systems.

CONCLUSIONS

Participants highlighted several helpful and not helpful features of drug treatment programs in terms of supporting treatment access and retention. Previous studies with PWUS and in other places have reported similar features, some of which (e.g., wait times) have been reported for many years. Changes are needed to reduce barriers to access and retention including the changes recommended by study participants. It is critical that the voices of key groups, (including PWUS) are heard to ensure treatment programs in all places support access and retention.

Feeling safer: effectiveness, feasibility, and acceptability of continuous pulse oximetry for people who smoke opioids at overdose prevention services in British Columbia, Canada

BACKGROUND

Smoking is the most common mode of unregulated opioid consumption overall and implicated in fatal overdoses in British Columbia (BC). In part, perception of decreased risk (e.g., fewer who smoke carry naloxone kits) and limited smoking-specific harm reduction services contribute to overdose deaths. Overdose prevention services (OPS) offer supervised settings for drug use. Continuous pulse oximetry, common in acute care, allows real-time, remote oxygen monitoring. We evaluated the effectiveness of a novel continuous pulse oximetry protocol aimed at allowing physical distancing (as required by COVID-19, secluded spaces, and to avoid staff exposure to vaporized opioids), its feasibility, and acceptability at OPS for people who smoke opioids.

METHODS

This was a mixed methods survey study. We developed a continuous pulse oximetry protocol in collaboration with clinical experts and people with lived/living experience of substance use. We implemented our protocol from March to August 2021 at four OPS in BC permitting smoking. We included adults (≥ 18 years) presenting to OPS to smoke opioids. Peer researchers collected demographic, health, and substance use information, and conducted structured observations. OPS clients participating in our study, OPS staff, and peer researchers completed post-monitoring surveys. We analyzed responses using a thematic inductive approach and validated themes with peer researchers.

RESULTS

We included 599 smoking events. OPS clients participating in our study had a mean age of 38.5 years; 73% were male. Most (98%) reported using "down", heroin, or fentanyl; 48% concurrently used other substances (32% of whom reported stimulants); 76% reported smoking alone in the last 3 days; and 36% reported an overdose while smoking. Respondents reported that the protocol facilitated physical distancing, was easy to use, high satisfaction, improved confidence, improved sense of safety, and that they would use it again.

CONCLUSIONS

Continuous pulse oximetry allowed safe physical distancing, was feasible, and acceptable in monitoring people who smoke opioids at OPS.

Factors associated with obtaining prescribed safer supply among people accessing harm reduction services: findings from a cross-sectional survey

BACKGROUND

With growing rates of unregulated drug toxicity death and concerns regarding COVID-19 transmission among people who use drugs, in March 2020, prescribed safer supply guidance was released in British Columbia. This study describes demographic and substance use characteristics associated with obtaining prescribed safer supply and examines the association between last 6-month harm reduction service access and obtaining prescribed safer supply.

METHODS

Data come from the 2021 Harm Reduction Client Survey administered at 17 harm reduction sites across British Columbia. The sample included all who self-reported use of opioids, stimulants, or benzodiazepines in the prior 3 days (N = 491), given active use of these drugs was a requirement for eligibility for prescribed safer supply. The dependent variable was obtaining a prescribed safer supply prescription (Yes vs. No). The primary independent variables were access to drug checking services and access to overdose prevention services in the last 6 months (Yes vs. No). Descriptive statistics (Chi-square tests) were used to compare the characteristics of people who did and did not obtain a prescribed safer supply prescription. Multivariable logistic regression models were run to examine the association of drug checking services and overdose prevention services access with obtaining prescribed safer supply.

RESULTS

A small proportion (n = 81(16.5%)) of the sample obtained prescribed safer supply. After adjusting for gender, age, and urbanicity, people who reported drug checking services access in the last 6 months had 1.67 (95% CI 1.00-2.79) times the odds of obtaining prescribed safer supply compared to people who had not contacted these services, and people who reported last 6 months of overdose prevention services access had more than twice the odds (OR 2.08 (95% CI 1.20-3.60)) of prescribed safer supply access, compared to people who did not access these services.

CONCLUSIONS

Overall, the proportion of respondents who received prescribed safer supply was low, suggesting that this intervention is not reaching all those in need. Harm reduction services may serve as a point of contact for referral to prescribed safer supply. Additional outreach strategies and service models are needed to improve the accessibility of harm reduction services and of prescribed safer supply in British Columbia.

Longitudinal polysubstance use patterns and non-fatal overdose: A repeated measures latent class analysis

BACKGROUND

Polysubstance use (PSU) is common among people who use opioids (PWUO) and has been associated with drug-related harms. We aimed to identify latent longitudinal PSU classes among a cohort of PWUO and characterize non-fatal overdose risks among different sub-classes over time.

METHODS

We used longitudinal data (2005-2018) from three ongoing prospective cohorts of people who use drugs in Vancouver, Canada. The primary outcome of interest was self-reported non-fatal overdose during the past six months. The primary exposure of interest was longitudinal PSU patterns among PWUO, obtained from repeated measures latent class analysis (RMLCA) of weekly substance use-related outcome indicators. Multivariable generalized estimating equations models were built to assess the association between latent PSU class membership and non-fatal overdose, adjusting for potential sociodemographic, behavioural, and structural confounders.

RESULTS

2627 PWUO were included in the analysis, and 1094 (41.6 %) had experienced at least one non-fatal overdose during the study period. RMLCA revealed five distinct latent longitudinal PSU classes, including low/infrequent use (Class 1; 30 %), primarily opioid and methamphetamine use (Class 2; 22 %), primarily cannabis use (Class 3; 15 %), primarily opioid and crack use (Class 4; 29 %), and frequent PSU (Class 5; 4 %). In comparison with Class 1 (low), membership in all latent PSU classes except Class 3 (cannabis) was associated with increased odds of non-fatal overdose: Class 2 (opioids + meth) vs. Class 1 (Adjusted odds ratios [aOR] = 2.20, 95 % confidence intervals [CI]: 1.51-3.22), Class 4 (opioids + crack) vs. Class 1 (aOR = 1.06, 95 % CI: 0.85-1.33), and Class 5 (frequent) vs. Class 1 (aOR = 2.39, 95 % CI: 1.92-2.97).

CONCLUSION

Our findings highlighted the heterogeneous characteristics of PWUO in terms of patterns of PSU and non-fatal overdose risk. The diverse nature of PWUO and the potential additive or multiplicative impact of using several substances on overdoses should be reflected across the substance use treatment continuum and care provision.

Fentanyl Concentration in Drug Checking Samples and Risk of Overdose Death in Vancouver, Canada

INTRODUCTION

The proliferation of fentanyl and its analogs in illegal, unregulated drug markets remains a major driver of the overdose crisis in North America. Drug checking services have been implemented as a harm reduction strategy to address the crisis. However, little is known about their potential utility as a mechanism for monitoring population-level risk of overdose stemming from changing fentanyl concentration in unregulated drugs over time. Therefore, this study assessed the relationship between median fentanyl concentration in expected opioid drug checking samples and the death rate due to illicit drug toxicity over time in Vancouver, Canada.

METHODS

Monthly population-based rates of death due to illicit drug toxicity were drawn from provincial coroner records. Monthly median percent fentanyl concentration was calculated using a validated quantification model from point-of-care Fourier-transform infrared spectra among expected opioid samples that tested positive for fentanyl at community drug checking services. A time-series analysis using generalized additive modeling was conducted to examine the association between monthly median fentanyl concentration and monthly death rate due to illicit drug toxicity, controlling for calendar month. Analyses were conducted in 2021-2022.

RESULTS

Between January 2019 and October 2020, 577 deaths due to illicit drug toxicity occurred in Vancouver, and the observed monthly rate ranged from 1.75 to 7.65 deaths per 100,000 population. A significant, positive association was observed between monthly median fentanyl concentration and monthly death rate due to illicit drug toxicity, adjusting for calendar month (chi-square=52.21, p<0.001).

CONCLUSIONS

Findings suggest a role for point-of-care drug checking as a tool for monitoring evolving overdose risk at the population level.

Motivators of and barriers to drug checking engagement in British Columbia, Canada: Findings from a cross-sectional study

OBJECTIVE

Responding to increasing rates of illicit drug toxicity mortality in British Columbia, regional health authorities introduced various types and models of drug checking services starting in 2016. Uptake has been gradual yet consistent, but motivators and barriers of service use have not been well-described.

METHODS

The British Columbia Harm Reduction Client Survey is a cross-sectional survey conducted at harm reduction sites across British Columbia. Data for the present findings were collected between March 2021 and January 2022. Participants (n = 537) were asked about their use of drug checking services and what prevented them from using available services. Responses were analyzed with descriptive statistics and multivariable logistic regression.

RESULTS

Of all participants, 519 (96.6 %) answered the survey question on drug checking with 144 (27.7 %) reporting having used services within six months. Participants highlighted barriers such as not knowing where to access services (21.0 %), or not having services in their area (10.0 %). Among people who did not report recent use of fentanyl, 49.6 % stated they would not use their drugs if they tested positive for fentanyl. Other harm reduction behaviors were positively associated with drug checking, such as use of overdose prevention sites (adjusted odds ratio [AOR]: 2.75, 95 % confidence interval [CI]: 1.65, 4.59) and having a naloxone kit (AOR: 2.67, 95 %CI: 1.14, 6.28). Receipt of opioid agonist therapy in the previous six months was also positively associated with drug checking (AOR: 1.72, 95 %CI: 1.05, 2.83).

DISCUSSION

Drug checking uptake remains low in British Columbia, however this study identified desire for services among participants, suggesting a need for expanded drug checking services. Behavioral change was reported among a high proportion of people who said they would not use their drugs if they tested positive for fentanyl, meaning that immunoassay strips alone have utility in the context of a pervasive fentanyl supply.

Associations with experience of non-fatal opioid overdose in British Columbia, Canada: a repeated cross sectional survey study

INTRODUCTION

Lives lost in North America due to the unregulated drug poisoning emergency are preventable and those who survive an opioid overdose may suffer long-term disability. Rates of opioid overdose more than doubled following the onset of the COVID-19 pandemic in British Columbia, Canada.

MATERIALS AND METHODS

Our analytical sample was comprised of 1447 participants from the 2018, 2019, and 2021 Harm Reduction Client Survey who responded yes or no to having experienced an opioid overdose in the past 6 months. Participants were recruited from harm reduction sites from across British Columbia. We used logistic regression to explore associations of experiencing an opioid overdose.

RESULTS

Overall, 21.8% of participants reported experiencing an opioid overdose in the last six months (18.2% in 2019 and 26.6% in 2021). The following factors were positively associated with increased adjusted odds of experiencing a non-fatal opioid overdose: cis men relative to cis women (AOR 1.49, 95% CI 1.10-2.02), unstably housed compared to people with stable housing (AOR 1.87, 95% CI 1.40-2.50), and participants from 2021 compared to those from 2019 (AOR 3.06, 95% CI 1.57-5.97). The effects of both previous experience of a stimulant overdose and having witnessed an opioid overdose depended on the year of study, with both effects decreasing over subsequent years.

CONCLUSIONS

Overdoses have increased over time; in 2021 more than one in four participants experienced an overdose. There is an urgent need for policy and program development to meaningfully address the unregulated drug poisoning emergency through acceptable life-saving interventions and services to prevent overdoses and support overdose survivors.

"A different sense of what we do here, who we are and what we deliver": Provider perspectives on the effects of a change in governance of healthcare services in correctional facilities in British Columbia

In 2017, British Columbia (BC) transferred responsibility for healthcare services in provincial correctional facilities from the Ministry of Public Safety and Solicitor General to the Ministry of Health. This study explored how healthcare leadership perceived the impact of the transfer on services, work-life, and job satisfaction. We conducted one-on-one interviews (n = 8) with healthcare managers and medical and administrative leadership within Correctional Health Services. Using the Two-Factor theory of job satisfaction as a framework, we applied Interpretive Description methodology to analyse interview data. Participants identified changes to four areas of the working environment: (1) staffing, equipment, and resources (2) systems of supervision and support (3) standards, policies, and quality improvement and (4) culture and orientation. These changes predominantly affected motivational factors of job satisfaction and were described as enriching the roles of managers and staff. Participants described improved autonomy and recognition of providers, increased quality of services delivered, and a shift toward patient-centred care. The perspectives of healthcare leaders provide new insight into the potential impact of transferring healthcare services in custody to a public healthcare system. Discussion of changes and their affects also provide practical learning for jurisdictions seeking to improve healthcare under a variety of governance and service-delivery models.

Preferred stimulant safer supply and associations with methamphetamine preference among people who use stimulants in British Columbia: Findings from a 2021 cross-sectional survey

BACKGROUND

As safer supply programs expand in Canada, stimulant safer supply is often overlooked despite the harms and criminalization faced by people who use stimulants.

METHODS

The 2021 Harm Reduction Client Survey was administered at 17 harm reduction sites around British Columbia, Canada. The survey included a question about what specific substance participants would want to receive as stimulant safer supply. We investigated preference of stimulant safer substance by looking at frequency of stated preference and by using multivariable logistic regression to understand factors associated with the most frequently chosen substance.

RESULTS

Of 330 participants who reported a stimulant safer supply preference, 58.5% (n = 193) chose crystal methamphetamine, 13% (n = 43) crack cocaine and 12.4% (n = 41) cocaine powder. The options that were available by prescription at the time of data collection were chosen by under 11% of participants (dextroamphetamine n = 21, methylphenidate n = 15). A preference for crystal methamphetamine was associated with being 29 and under compared to 50 and over (AOR: 3.96, 95% CI: 1.42-11.07, p-value: 0.01); self-identifying as a cis man versus a cis woman (AOR: 1.75, 95% CI: 1.03-2.97, p-value: 0.04); and using drugs every day (AOR: 15.43, 95% CI: 3.38-70.51, p-value: < 0.01) or a few times a week (AOR: 8.90, 95% CI: 1.78-44.44, p-value: 0.01) compared to a few times a month.

CONCLUSIONS

Preference of stimulant safer supply is associated with age, gender, and substance use characteristics. Safer supply programs that offer limited substances risk being poorly accessed, resulting in a continued reliance on an unregulated supply. Moreover, programs that do not offer a range of substances can contribute to health inequities.

Longitudinal latent polysubstance use patterns among a cohort of people who use opioids in Vancouver, Canada

INTRODUCTION

Polysubstance use (PSU) practices are increasing among people who use opioids (PWUO). However, several aspects of longitudinal PSU patterns among PWUO remain understudied. This study aims to identify person-centred longitudinal patterns of PSU among a cohort of PWUO.

METHODS

Using longitudinal data (2005-2018) from three prospective cohort studies including people who use drugs in Vancouver, Canada, we used repeated measures latent class analysis to identify different PSU classes among PWUO. Multivariable generalised estimating equations models weighted by the respective posterior membership probabilities were applied to identify covariates of membership in different PSU classes over time.

RESULTS

Overall, 2627 PWUO (median age at baseline: 36 [quartile 1-3: 25-45]) were included between 2005 and 2018. We found five distinct PSU patterns, including low/infrequent probability of regular substance use (Class 1; 30%), primarily opioid and methamphetamine use (Class 2; 22%), primarily cannabis use (Class 3; 15%), primarily opioid and crack use (Class 4; 29%) and frequent PSU (Class 5; 4%). Membership in Class 2, 4 and 5 was positively associated with several behavioural and socio-structural adversities.

DISCUSSION AND CONCLUSIONS

Findings of this longitudinal study suggest PSU is the norm among PWUO and highlights the heterogeneous characteristics of PWUO. The diversities within the population of PWUO need to be recognised in addiction care and treatment as well as optimising resource allocation in the response to the overdose crisis.

Guidance on take-home naloxone distribution and use by community overdose responders in Canada

BACKGROUND

The increasing toxicity of opioids in the unregulated drug market has led to escalating numbers of overdoses in Canada and worldwide; takehome naloxone (THN) is an evidence-based intervention that distributes kits containing naloxone to people in the community who may witness an overdose. The purpose of this guidance is to provide policy recommendations for territorial, provincial and federal THN programs, using evidence from scientific and grey literature and community evidence that reflects 11 years of THN distribution in Canada.

METHODS

The Naloxone Guidance Development Group - a multidisciplinary team including people with lived and living experience and expertise of drug use - used the Appraisal of Guidelines for Research & Evaluation (AGREE II) instrument to inform development of this guidance. We considered published evidence identified through systematic reviews of all literature types, along with community evidence and expertise, to generate recommendations between December 2021 and September 2022. We solicited feedback on preliminary recommendations through an External Review Committee and a public input process. The project was funded by the Canadian Institutes of Health Research through the Canadian Research Initiative in Substance Misuse. We used the Guideline International Network principles for managing competing interests.

RECOMMENDATIONS

Existing evidence from the literature on THN was of low quality. We incorporated evidence from scientific and grey literature, and community expertise to develop our recommendations. These were in 3 areas: routes of naloxone administration, THN kit contents and overdose response. Take-home naloxone programs should offer the choice of both intramuscular and intranasal formulations of naloxone in THN kits. Recommended kit contents include naloxone, a naloxone delivery device, personal protective equipment, instructions and a carrying case. Trained community overdose responders should prioritize rescue breathing in the case of respiratory depression, and conventional cardiopulmonary resuscitation in the case of cardiac arrest, among other interventions.

INTERPRETATION

This guidance development project provides direction for THN programs in Canada in the context of limited published evidence, with recommendations developed in collaboration with diverse stakeholders.

Association between toxic drug events and encephalopathy in British Columbia, Canada: a cross-sectional analysis

BACKGROUND

Encephalopathy can occur from a non-fatal toxic drug event (overdose) which results in a partial or complete loss of oxygen to the brain, or due to long-term substance use issues. It can be categorized as a non-traumatic acquired brain injury or toxic encephalopathy. In the context of the drug toxicity crisis in British Columbia (BC), Canada, measuring the co-occurrence of encephalopathy and drug toxicity is challenging due to lack of standardized screening. We aimed to estimate the prevalence of encephalopathy among people who experienced a toxic drug event and examine the association between toxic drug events and encephalopathy.

METHODS

Using a 20% random sample of BC residents from administrative health data, we conducted a cross-sectional analysis. Toxic drug events were identified using the BC Provincial Overdose Cohort definition and encephalopathy was identified using ICD codes from hospitalization, emergency department, and primary care records between January 1st 2015 and December 31st 2019. Unadjusted and adjusted log-binomial regression models were employed to estimate the risk of encephalopathy among people who had a toxic drug event compared to people who did not experience a toxic drug event.

RESULTS

Among people with encephalopathy, 14.6% (n = 54) had one or more drug toxicity events between 2015 and 2019. After adjusting for sex, age, and mental illness, people who experienced drug toxicity were 15.3 times (95% CI = 11.3, 20.7) more likely to have encephalopathy compared to people who did not experience a drug toxicity event. People who were 40 years and older, male, and had a mental illness were at increased risk of encephalopathy.

CONCLUSIONS

There is a need for collaboration between community members, health care providers, and key stakeholders to develop a standardized approach to define, screen, and detect neurocognitive injury related to drug toxicity.

Qualitative Exploration of Emergency Department Care Experiences Among People With Opioid Use Disorder

STUDY OBJECTIVE

We described the experiences and preferences of people with opioid use disorder who access emergency department (ED) services regarding ED care and ED-based interventions.

METHODS

Between June and September 2020, we conducted phone or in-person semistructured qualitative interviews with patients recently discharged from 2 urban EDs in Vancouver, BC, Canada, to explore experiences and preferences of ED care and ED-based opioid use disorder interventions. We recruited participants from a cohort of adults with opioid use disorder who were participating in an ED-initiated outreach program. We transcribed audio recordings verbatim. We iteratively developed a thematic coding structure, with interim analyses to assess for thematic saturation. Two team members with lived experience of opioid use provided feedback on content, wording, and analysis throughout the study.

RESULTS

We interviewed 19 participants. Participants felt discriminated against for their drug use, which led to poorer perceived health care and downstream ED avoidance. Participants desired to be treated like ED patients who do not use drugs and to be more involved in their ED care. Participants nevertheless felt comfortable discussing their substance use with ED staff and valued continuous ED operating hours. Regarding opioid use disorder treatment, participants supported ED-based buprenorphine/naloxone programs but also suggested additional options (eg, different initiation regimens and settings and other opioid agonist therapies) to facilitate further treatment uptake.

CONCLUSION

Based on participant experiences, we recommend addressing potentially stigmatizing practices, increasing patient involvement in their care during ED visits, and increasing access to various opioid use disorder-related treatments and community support.

Precarious Housing Associated with Unsuppressed Viral load, sub-optimal Access to HIV Treatment and Unmet Health care Needs, Among Women Living with HIV in Metro Vancouver, Canada

We investigated associations between (1) housing status (four categories measuring housing stability) and outcomes along the HIV care continuum (not currently on antiretroviral therapy [ART]; sub-optimal ART adherence [< 95% in the last 3-4 weeks]; unsuppressed viral load [> 200 copies/ml], median CD4 < 200 in the last six months), and (2) housing status and unmet primary, dental and mental health care needs in the last six months among WLWH. Housing status was defined according to the Canadian Definition of Homelessness and had four categories: unsheltered (i.e., living in ≥ 1 unsheltered location [e.g., street, abandoned buildings]), unstable (i.e., living in ≥ 1 unstable location [e.g., shelter, couch surfing]), supportive housing (i.e., only living in supportive housing), and stable housing (i.e., only living in one's own housing; reference). At baseline, in the last six months, 47.3% of participants reported unstable housing, followed by 24.4% unsheltered housing, 16.4% stable housing, and 11.9% supportive housing. Overall, 19.1% of the full sample (N = 336, 2010-2019) reported not currently on ART; among participants on ART, 28.0% reported sub-optimal ART adherence. Overall, 32.1% had recent unsuppressed viral load. Among a subsample (n = 318, 2014-2019), 15.7% reported unmet primary care needs, 26.1% unmet dental care needs, and 16.4% unmet mental health care needs. In adjusted models, being unsheltered (vs. stable housing) was associated with not currently on ART, unsuppressed viral load, and unmet primary and dental care needs. Housing and health services need to be developed with and for WLWH to address structural inequities and fulfill basic rights to housing and health.

Reasonable access: important characteristics and perceived quality of legal and illegal sources of cannabis for medical purposes in Canada

BACKGROUND

Throughout the past two decades of legal medical cannabis in Canada, individuals have experienced challenges related to accessing legal sources of cannabis for medical purposes. The objective of our study was to examine the sources of cannabis accessed by individuals authorized to use medical cannabis and to identify possible reasons for their use of illegal sources.

METHODS

Individuals who participated in the Cannabis Access Regulations Study (CANARY), a national cross-sectional survey launched in 2014, and indicated they were currently authorized to use cannabis for medical purposes in Canada were included in this study. We assessed differences between participants accessing cannabis from only legal sources versus from illegal sources in relation to sociodemographic characteristics, health-related factors, and characteristics of medical cannabis they considered important. A secondary analysis assessed differences in satisfaction with various dimensions of cannabis products and services provided by legal versus illegal sources.

RESULTS

Half of the 237 study participants accessed cannabis from illegal sources. Individuals accessing cannabis from illegal sources were significantly more likely to value pesticide-free products, access to a variety of strains, ability to select strain and dosage, ability to observe and smell cannabis, availability in a dispensary, and availability in small quantities than did individuals accessing cannabis from only legal sources (all p < 0.05). Additionally, participants gave significantly higher satisfaction scores to illegal sources than to legal sources on service-related dimensions of cannabis access (all p < 0.05).

CONCLUSION

Our findings contribute to an understanding of reasonable access to medical cannabis from a patient perspective and how to assess whether it has been achieved. Characteristics of cannabis products and services valued by patients and appropriate to their needs should be incorporated into legal medical cannabis programs to promote the use of legal medical sources. While pertaining specifically to medical use of cannabis in Canada, the findings of this study may also be instructive for understanding the use of illegal cannabis sources for non-medical purposes in Canada and provide insight for other jurisdictions implementing cannabis regulations for both medical and non-medical purposes.

Smoking identified as preferred mode of opioid safe supply use; investigating correlates of smoking preference through a 2021 cross-sectional study in British Columbia

BACKGROUND

The increasing number of illicit drug toxicity deaths in British Columbia (BC) has led to calls for a regulated (pharmaceutical grade) supply of substances ("safe supply"). In order to inform safe supply recommendations, we aimed to identify why people currently smoke opioids and assess the preferred mode of consumption if people who use opioids were provided with opioid safe supply.

METHODS

The BC Harm Reduction Client Survey (HRCS) is an annual survey that gathers information about people who use drugs' (PWUD) substance use characteristic with the goal of contributing to evidence-based policy. This study utilized data from the 2021 HRCS. The outcome variable was "prefer smoking opioid safe supply" ('yes/no'). Explanatory variables included participants' demographics, drug use, and overdose characteristics. Bivariate and hierarchical multivariable logistic regressions were conducted to identify factors associated with the outcome.

RESULTS

Of 282 total participants who indicated a preference for a mode of consumption for opioid safe supply, 62.4% preferred a smokable option and 19.9% preferred to inject if provided with opioid safe supply. Variables significantly associated with the outcome (preferred smoking) included: being 19-29 years old (AOR=5.95, CI =1.93 - 18.31) compared to >50 years old, having witnessed an overdose in the last 6 months (AOR=2.26, CI=1.20 - 4.28), having smoked opioids in the last 3 days (AOR=6.35, CI=2.98 - 13.53) and having a preference to smoke stimulants safe supply (AOR=5.04, CI=2.53 - 10.07).

CONCLUSION

We found that over half of participants prefer smokable options when accessing opioid safe supply. Currently in BC, there are limited smokable opioid safe supply options as alternatives to the toxic street supply. To reduce overdose deaths, safe supply options should be expanded to accommodate PWUD that prefer smoking opioids.

Awareness, predictors and outcomes of drug alerts among people who access harm reduction services in British Columbia, Canada: findings from a 2021 cross-sectional survey

OBJECTIVES

To assess the awareness and predictors of seeing/hearing a drug alert in British Columbia (BC) and subsequent drug use behaviour after seeing/hearing an alert.

METHODS

This study analysed the 2021 BC harm reduction client survey (HRCS)-a cross-sectional self-reported survey administered at harm reduction sites throughout the province and completed by participants using the services.

RESULTS

In total, n=537 respondents participated and n=482 (89.8%) responded to the question asking if they saw/heard a drug alert. Of those, n=300 (62.2%) stated that they saw/heard a drug alert and almost half reported hearing from a friend or peer network; the majority (67.4%) reported altering their drug use behaviour to be safer after seeing/hearing a drug alert. The proportion of individuals who saw/heard a drug alert increased with each ascending age category. Among health authorities, there were significant differences in the odds of seeing/hearing an alert. In the past 6 months, the odds of participants who attended harm reduction sites a few times per month seeing/hearing an alert were 2.73 (95% CI: 1.17 to 6.52) times the odds of those who did not. Those who attended more frequently were less likely to report seeing/hearing a drug alert. The odds of those who witnessed an opioid-related overdose in the past 6 months seeing/hearing an alert were 1.96 (95% CI: 0.86 to 4.50) times the odds of those who had not.

CONCLUSION

We found that drug alerts were mostly disseminated through communication with friends or peers and that most participants altered their drug use behaviour after seeing/hearing a drug alert. Therefore, drug alerts can play a role in reducing harms from substance use and more work is needed to reach diverse populations, such as younger people, those in differing geographical locations, and those who attend harm reduction sites more frequently.

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.

"It's just a perfect storm": Exploring the consequences of the COVID-19 pandemic on overdose risk in British Columbia from the perspectives of people who use substances

BACKGROUND

Despite the implementation and expansion of public health and harm reduction strategies aimed at preventing and reversing overdoses, rates of overdose-related events and fatalities continue to rise in British Columbia. The COVID-19 pandemic created a second, concurrent public health emergency that further exacerbated the illicit drug toxicity crisis, reinforced existing social inequities and vulnerabilities, and highlighted the precariousness of systems in place that are meant to protect the health of communities. By exploring the perspectives of people with recent experience of illicit substance use, this study sought to characterize how the COVID-19 pandemic and associated public health measures influenced risk and protective factors related to unintentional overdose by altering the environment in which people live and use substances, influencing the ability of people who use substances to be safe and well.

METHODS

One-on-one semi-structured interviews were conducted by phone or in-person with people who use illicit substances (n = 62) across the province. Thematic analysis was performed to identify factors shaping the overdose risk environment.

RESULTS

Participants pointed to factors that increased risk of overdose, including: [1] physical distancing measures that created social and physical isolation and led to more substance use alone without bystanders nearby able to respond in the event of an emergency; [2] early drug price spikes and supply chain issues that created inconsistencies in drug availability; [3] increasing toxicity and impurities in unregulated substances; [4] restriction of harm reduction services and supply distribution sites; and [5] additional burden placed on peer workers on the frontlines of the illicit drug toxicity crisis. Despite these challenges, participants highlighted factors that protected against overdose and substance-related harm, including the emergence of new programs, the resiliency of communities of people who use substances who expanded their outreach efforts, the existence of established social relationships, and the ways that individuals consistently prioritized overdose response over concerns about COVID-19 transmission to care for one another.

CONCLUSIONS

The findings from this study illustrate the complex contextual factors that shape overdose risk and highlight the importance of ensuring that the needs of people who use substances are addressed in future public health emergency responses.

Drug overdose and the risk of cardiovascular diseases: a nested case-control study

BACKGROUND

North America has been experiencing an unprecedented epidemic of drug overdose. This study investigated the associations of drug overdose with the risk of cardiovascular disease (CVD) and 11 major CVD subtypes.

METHODS

This nested case-control study was based on a cohort of 20% random sample of residents in British Columbia, Canada, who were aged 18-80 years and did not have known CVD at baseline (n = 617,863). During a 4-year follow-up period, persons who developed incident CVD were identified as case subjects, and the onset date of CVD was defined as the index date. For each case subject, we used incidence density sampling to randomly select up to five control subjects from the cohort members who were alive and did not have known CVD by the index date, were admitted to an emergency department or hospital on the index date for non-CVD causes, and were matched on age, sex, and region of residence. Overdose exposure on the index date and each of the previous 5 days was examined for each subject.

RESULTS

This study included 16,113 CVD case subjects (mean age 53 years, 59% male) and 66,875 control subjects. After adjusting for covariates, overdose that occurred on the index date was strongly associated with CVD [odds ratio (OR), 2.9; 95% confidence interval (CI), 2.4-3.5], especially for arrhythmia (OR, 8.6; 95% CI, 6.2-12.0), ischemic stroke (OR, 5.3; 95% CI, 2.0-14.1), hemorrhagic stroke (OR, 3.1; 95% CI, 1.2-8.3), and myocardial infarction (OR, 3.0; 95% CI, 1.5-5.8). The CVD risk was decreased but remained significantly elevated for overdose that occurred on the previous day, and was not observed for overdose that occurred on each of the previous 2-5 days.

CONCLUSIONS

Drug overdose appears to be associated with increased risk of cardiovascular diseases.

The impact of poisoning in British Columbia: a cost analysis

BACKGROUND

Poisoning, from substances such as illicit drugs, prescribed and over-the-counter medications, alcohol, pesticides, gases and household cleaners, is the leading cause of injury-related death and the second leading cause for injury-related hospital admission in British Columbia. We examined the health and economic costs of poisoning in BC for 2016, using a societal perspective, to support public health policies aimed at minimizing losses to society.

METHODS

Costs by intent, sex and age group were calculated in Canadian dollars using a classification and costing framework based on existing provincial injury data combined with data from the published literature. Direct cost components included fatal poisonings, hospital admissions, emergency department visits, ambulance attendance without transfer to hospital and calls to the British Columbia Drug and Poison Information Centre (BC DPIC) not resulting in ambulance attendance, emergency care or transfer to hospital. Indirect costs, measured as loss of earnings and informal caregiving costs, were also calculated.

RESULTS

We estimate that poisonings in BC totalled $812.5 million in 2016 with $108.9 million in direct health care costs and $703.6 million in indirect costs. Unintentional poisoning injuries accounted for 84% of total costs, 46% of direct costs and 89% of indirect costs. Males accounted for higher proportions of direct costs for all patient dispositions except hospital admissions. Patients aged 25-64 years accounted for higher proportions of direct costs except for calls to BC DPIC, where proportions were highest for children younger than 15 years.

INTERPRETATION

Hospital care expenditures represented the largest direct cost of poisoning, and lost productivity following death represented the largest indirect cost. Quantifying and understanding the financial burden of poisoning has implications not only for government and health care, but also for society, employers, patients and families.

The Cost of Caring: Compassion Fatigue among Peer Overdose Response Workers in British Columbia

Background: The drug toxicity crisis has had dramatic impacts on people who use drugs. Peer overdose response workers (peer responders), i.e., individuals with lived/living experience of drug use who work in overdose response settings, are particularly susceptible to negative physical and mental health impacts of the crisis. Despite that, the mental health impacts on peer responders have yet to be studied and measured. Methods: The Professional Quality of Life survey (Version 5) was completed by 47 peer responders at two organizations in British Columbia between September 2020 and March 2021 to assess compassion satisfaction and compassion fatigue. The Likert scale responses were converted into numerical values and scores were calculated for each sub-scale. The mean score was calculated for each sub-scale and categorized as low, medium, or high, based on the instructions for Version 5 of the instrument. Results: Our study uncovered a high mean score for compassion satisfaction, low mean score for burnout, and medium mean score for secondary traumatic stress among peer responders. These results may be due to the participants' strong feelings of pride and recognition from their work, as well as the low number of participants that felt they had too much to do at work. Conclusion: Although peer responders derive pleasure and fulfillment from their jobs, i.e., compassion satisfaction, they also sometimes face burnout and stress due to continuous exposure to the trauma of the people they support. These results shed light on the areas that need to be targeted when creating supports for peer responders.

Factors associated with changes in illicit opioid use during the COVID-19 pandemic among incarcerated people who use drugs in Quebec, Canada

PURPOSE

People who use drugs (PWUD) have been disproportionately affected by the COVID-19 pandemic. This study aims to examine changes in illicit opioid use and related factors among incarcerated PWUD in Quebec, Canada, during the pandemic.

DESIGN/METHODOLOGY/APPROACH

The authors conducted an observational, cross-sectional study in three Quebec provincial prisons. Participants completed self-administered questionnaires. The primary outcome, "changes in illicit opioid consumption," was measured using the question "Has your consumption of opioid drugs that were not prescribed to you by a medical professional changed since March 2020?" The association of independent variables and recent changes (past six months) in opioid consumption were examined using mixed-effects Poisson regression models with robust standard errors. Crude and adjusted risk ratios with 95% confidence intervals (95% CIs) were calculated.

FINDINGS

A total of 123 participants (median age 37, 76% White) were included from January 19 to September 15, 2021. The majority (72; 59%) reported decreased illicit opioid consumption since March 2020. Individuals over 40 were 11% less likely (95% CI 14-8 vs 18-39) to report a decrease, while those living with others and with a history of opioid overdose were 30% (95% CI 9-55 vs living alone) and 9% (95% CI 0-18 vs not) more likely to report decreased illicit opioid consumption since March 2020, respectively.

ORIGINALITY/VALUE

The authors identified possible factors associated with changes in illicit opioid consumption among incarcerated PWUD in Quebec. Irrespective of opioid consumption patterns, increased access to opioid agonist therapy and enhanced discharge planning for incarcerated PWUD are recommended to mitigate the harms from opioids and other drugs.

Awareness and knowledge of the Good Samaritan Drug Overdose Act among people at risk of witnessing an overdose in British Columbia, Canada: a multi-methods cross sectional study

Introduction

Bystanders to drug overdoses often avoid or delay calling 9–1-1 and cite fear of police involvement as a main reason. In 2017, the Good Samaritan Drug Overdose Act (GSDOA) was enacted by the Canadian government to provide people present at an overdose with legal protection from charges for simple drug possession, and conditions stemming from simple possession. Few studies have taken a multi-methods approach to evaluating the GSDOA. We used quantitative surveys and qualitative interviews to explore awareness, understanding, and perceptions of the GSDOA in people at risk of witnessing an overdose.

Methods

Quantitative cross-sectional surveys and qualitative telephone interviews were conducted with adults and youth at risk of witnessing an overdose across British Columbia. Cross-sectional survey participants were recruited at 19 Take Home Naloxone sites and online through Foundry. Multivariable logistic regression models were constructed hierarchically to determine factors associated with GSDOA awareness. Telephone interview participants were recruited by research assistants with lived/living experience of substance use. Deductive and inductive thematic analyses were conducted to identify major themes.

Results

Overall, 52.7% (n = 296) of the quantitative study sample (N = 453) reported being aware of the GSDOA. In multivariable analysis, cellphone possession (adjusted odds ratio [AOR] = 2.19; 95% confidence interval [CI] 1.36, 3.54) and having recently witnessed an opioid overdose (AOR = 2.34; 95% CI 1.45, 3.80) were positively associated with GSDOA awareness. Young adults (25 – 34 years) were more likely to be aware of the Act (AOR = 2.10; 95% CI 1.11, 3.98) compared to youth (16–24 years). Qualitative interviews (N = 42) revealed that many overestimated the protections offered by the GSDOA. To increase awareness and knowledge of the Act among youth, participants recommended adding the GSDOA to school curricula and using social media. Word of mouth was suggested to reach adults.

Conclusion

Both awareness and knowledge of the GSDOA remain low in BC, with many overestimating the protections the Act offers. Dissemination efforts should be led by people with lived/living experience and should target those with limited awareness and understanding of the Act as misunderstandings can erode trust in law enforcement and harm reduction policy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13011-022-00472-4.

Shifts in substance use patterns among a cohort of people who use opioids after delisting of OxyContin in BC, Canada: An interrupted time series study

BACKGROUND

OxyContin was delisted from Canadian provincial drug formularies in March 2012 and replaced with a reformulated tamper-resistant form of oxycodone (i.e., OxyNeo). We assessed if delisting of OxyContin was associated with changes in the use of unregulated opioids and other substances among people who use opioids (PWUO).

METHODS

Data were derived from two prospective cohort studies of people who use drugs in Vancouver, BC, Canada from 2006 to 2018. PWUO who had at least one follow-up visit before and after delisting of OxyContin were included. Outcomes of interest were self-reported regular (i.e., at least weekly) use of heroin, non-prescribed prescription opioids, cannabis, methamphetamine, crack cocaine, and powder cocaine during the previous six months. Using quasi-experimental interrupted time series, we fit generalized least squares models to assess participants' immediate and long-term substance use practices after the policy change.

RESULTS

We analyzed data from 1014 participants who contributed to 17457 visits during the study. Following the delisting of OxyContin, heroin use increased immediately by 5.17% (95% confidence intervals [CI]: 0.68 to 9.67) and over time by 0.47% (0.35 to 0.58) per month. Non-prescribed prescription opioid use increased immediately by 1.80% (0.10 to 3.50) and over time by 0.16% (0.12 to 0.19) per month. Cannabis use increased immediately by 4.37% (0.88 to 7.87) and over time by 0.11% (0.02 to 0.19) per month. Methamphetamine use did not increase immediately but increased over time by 0.10% (0.01 to 0.18) per month. Crack cocaine use decreased immediately by 6.13% (-10.94 to -1.69) but not significantly over time. Lastly, powder cocaine use did not increase immediately or over time.

CONCLUSIONS

Delisting of OxyContin in BC was not associated with a reduction in unregulated opioid use among PWUO. Our findings point to a shift in substance use patterns of PWUO post-intervention and further highlight the unintended consequences of supply-reduction interventions in addressing the opioid epidemic.

The prevalence and social-structural correlates of housing status among women living with HIV in Vancouver, Canada

Background

Women living with HIV (WLWH) experience numerous social and structural barriers to stable housing, with substantial implications for access to health care services. This study is the first to apply the Canadian Definition of Homelessness (CDOH), an inclusive national guideline, to investigate the prevalence and correlates of housing status among WLWH in Metro Vancouver, Canada.

Methods

Our study utilized data from a longitudinal open cohort of cisgender and trans WLWH aged 14 years and older, in 2010–2019. Cross-sectional descriptive statistics of the prevalence of housing status and other social and structural variables were summarized for the baseline visits. Bivariate and multivariable logistic regression analyses were conducted using generalized linear mixed models (GLMM) for repeated measures to investigate the relationship between social and structural correlates and housing status among WLWH.

Results

The study included 336 participants with 1930 observations over 9 years. Housing status derived from CDOH included four categories: unsheltered, unstable, supportive housing, and stable housing (reference). Evidence suggested high levels of precarious housing, with 24% of participants reporting being unsheltered, 47% reporting unstable housing, 11.9% reporting supportive housing, and 16.4% reporting stable housing in the last six months at baseline. According to the multivariable models, living in the Downtown Eastside (DTES) neighbourhood of Metro Vancouver, hospitalization, physical/sexual violence, and stimulant use were associated with being unsheltered, compared to stable housing; DTES residence, hospitalization, and physical/sexual violence were associated with unstable housing; DTES residence and stimulant use were associated with living in supportive housing.

Conclusion

Complex social-structural inequities are associated with housing instability among WLWH. In addition to meeting basic needs for living, to facilitate access to housing among WLWH, housing options that are gender-responsive and gender-inclusive and include trauma- and violence-informed principles, low-barrier requirements, and strong connections with supportive harm reduction services are critical.

Navigating Opioid Agonist Therapy among Young People who use Illicit Opioids in Vancouver, Canada

BACKGROUND

Opioid agonist therapy (OAT) has been shown to reduce opioid use and related harms. However, many young people are not accessing OAT. This study sought to explore how young people navigated OAT over time, including periods of engagement, disengagement, and avoidance.

METHODS

Semi-structured, in-depth qualitative interviews were conducted between January 2018 and August 2020 with 56 young people in Vancouver, Canada who reported illicit, intensive heroin and/or fentanyl use. Following the verbatim transcription of longitudinal interviews, an iterative thematic analysis was used to extrapolate key themes.

RESULTS

Young people contemplating OAT expressed fears about its addictiveness. Many experienced pressure from providers and family members to initiate buprenorphine-naloxone, despite a desire to explore other treatment options such as methadone. Once young people initiated OAT, staying on it was difficult and complicated by daily witnessed dosing requirements and strict rules around repeated missed doses, especially for those receiving methadone. Most young people envisioned tapering off OAT in the not-too-distant future.

CONCLUSIONS

Findings underscore the importance of working collaboratively with young people to develop treatment plans and timelines, and suggest that OAT engagement and retention among young people could be improved by expanding access to the full range of OAT; updating clinical guidelines to improve access to safer prescription alternatives to the increasingly poisonous, unregulated drug supply; addressing treatment gaps arising from missed doses and take-home dosing; and providing a clear pathway to OAT tapering.

Guideline development in harm reduction: Considerations around the meaningful involvement of people who access services

Background

Harm reduction seeks to minimizes the negative effects of drug use while respecting the rights of people with lived and living experience of substance use (PWLLE). Guideline standards ("guidelines for guidelines") provide direction on developing healthcare guidelines. To identify essential considerations for guideline development within harm reduction, we examined whether guideline standards are consistent with a harm reduction approach in their recommendations on involving people who access services.

Methods

We searched the literature from 2011-2021 to identify guideline standards used in harm reduction and publications on involving PWLLE in developing harm reduction services. We used thematic analysis to compare their guidance on involving people who access services. Findings were validated with two organizations of PWLLE.

Results

Six guideline standards and 18 publications met inclusion criteria. We identified three themes related to involving people who access services: Reasons for Involvement, Methods of Involvement, and Factors in Success. Subthemes varied across the literature. We identified five essential considerations for guideline development in harm reduction: establishing a shared understanding of reasons for involving PWLLE; respecting their expertise; partnering with PWLLE to ensure appropriate engagement; incorporating perspectives of populations disproportionately affected by substance use; and securing resources.

Conclusion

Guideline standards and the harm reduction literature approach the involvement of people who access services from different perspectives. Thoughtful integration of the two paradigms can improve guidelines while empowering PWLLE. Our findings can support the development of high-quality guidelines that align with the fundamental principles of harm reduction in their involvement of PWLLE.

Take-home drug checking as a novel harm reduction strategy in British Columbia, Canada

BACKGROUND

Drug checking is a harm reduction strategy used to identify components of illicitly obtained drugs, including adulterants, to prevent overdose. This study evaluated the distribution of take-home fentanyl test strips to people who use drugs (PWUD) in British Columbia, Canada. The primary aim was to assess if the detection of fentanyl in opioid samples was concordant between a take-home model and testing by trained drug checking staff.

METHODS

Take-home fentanyl test strips were distributed at ten sites providing drug checking services from April to July 2019. The fentanyl positivity of the aggregate take-home and on-site drug checking groups were compared by class of substance tested. An administered survey assessed acceptability and behaviour change.

RESULTS

1680 take-home results were obtained from 218 unique participants; 68% of samples (n=1142) were identified as opioids and 23% (n=382) were stimulant samples. During this period, 852 samples were tested using on-site drug checking. The fentanyl positivity of opioid samples was 90.0% for take-home samples and 89.1% for on-site samples (Difference 0.8% (95% CI -2.3% to 3.9%)). These results were not affected by previous experience with test strips. Fentanyl positivity of stimulants in the take-home group was higher than on-site (24.7% vs. 3.2%), but the study was underpowered to conduct statistical analysis on this sub-group. When fentanyl was detected, 27% of individuals reported behaviour change that was considered safer/positive. Greater than 95% of participants stated they would use fentanyl test strips again.

CONCLUSIONS

Take-home fentanyl test strips used by PWUD on opioid samples can provide similar results to formal drug checking services and are a viable addition to existing overdose prevention strategies. Use of this strategy for detection of fentanyl in stimulant samples requires further evaluation. This intervention was well accepted and in some participants was associated with positive behaviour change.

How COVID-19 has impacted access to healthcare and social resources among individuals experiencing homelessness in Canada: a scoping review

OBJECTIVES

In Canada, individuals experiencing homelessness (IEH) rely on public health and social services for healthcare, food and basic necessities. The COVID-19 pandemic has disproportionately affected marginalised populations, in part by impacting their access to such services. We performed a scoping review to identify from the published literature how access to services has changed for Canadian IEH during the pandemic.

DATA SOURCES

OVID Medline, Web of Science, Sociological Abstracts, CINAHL and OVID EmCare databases, and websites for the Salvation Army, Homeless Hub, Canadian Alliance to End Homelessness, Canadian Network for the Health and Housing of People Experiencing Homelessness and BC Centre for Disease Control.

STUDY DESIGN

We used the scoping review methodology developed by the Joanna Briggs Institute framework and defined access to healthcare and social services using the 10-component Levesque framework. Academic databases and grey literature searches were used, with the final searches for each taking place 24 May and 1 June 2021, respectively. Data were compiled into an Excel spreadsheet. Title and abstract screening and full-text review were completed by two independent reviewers (RG and MM). Data extraction was completed by MM and cross checked by RG.

RESULTS

In total, 17 academic and grey literature articles were included. Positive and negative changes in service access were reported in the literature. During the COVID-19 pandemic, access to social and healthcare resources was generally reduced for Canadian IEH. A new component of access, digital connectivity, was identified. Unexpectedly, coordination and collaboration of services improved, as did the number of outreach services.

CONCLUSIONS

Positive changes to service access such as improved coordination of services should be scaled up. Further work should be done to improve access to digital technologies for IEH.

Priority setting for Canadian Take-Home Naloxone best practice guideline development: an adapted online Delphi method

BACKGROUND

Take-Home Naloxone (THN) is a core intervention aimed at addressing the toxic illicit opioid drug supply crisis. Although THN programs are available in all provinces and territories throughout Canada, there are currently no standardized guidelines for THN programs. The Delphi method is a tool for consensus building often used in policy development that allows for engagement of stakeholders.

METHODS

We used an adapted anonymous online Delphi method to elicit priorities for a Canadian guideline on THN as a means of facilitating meaningful stakeholder engagement. A guideline development group generated a series of key questions that were then brought to a 15-member voting panel. The voting panel was comprised of people with lived and living experience of substance use, academics specializing in harm reduction, and clinicians and public health professionals from across Canada. Two rounds of voting were undertaken to score questions on importance for inclusion in the guideline.

RESULTS

Nine questions that were identified as most important include what equipment should be in THN kits, whether there are important differences between intramuscular and intranasal naloxone administration, how stigma impacts access to distribution programs, how effective THN programs are at saving lives, what distribution models are most effective and equitable, storage considerations for naloxone in a community setting, the role of CPR and rescue breathing in overdose response, client preference of naloxone distribution program type, and what aftercare should be provided for people who respond to overdoses.

CONCLUSIONS

The Delphi method is an equitable consensus building process that generated priorities to guide guideline development.

Initiation of opioid agonist treatment and subsequent substance use and other patterns among adolescents and young adults in Vancouver, Canada

BACKGROUND

Opioid agonist treatments (OAT) are effective interventions for reducing illicit opioid use; however, less is known about OAT among adolescents and young adults (AYA). This study sought to examine OAT retention and discontinuation among AYA.

METHODS

Data were derived from the At-Risk Youth Study, a prospective cohort of street-involved AYA in Vancouver, Canada, between September 2005 and December 2018. Multivariable Cox regression analysis was employed to identify sociodemographic, substance use, and other factors associated with time to first OAT. Substance use, homelessness, service utilization, and criminal justice patterns among AYA who did and did not initiate OAT were examined using before and after analysis.

RESULTS

Of 676 AYA who reported weekly illicit opioid use, 454 (67.2%) reported not being on OAT at some point over the study period and 217 (32.1%) initiated OAT over follow-up. In non-linear growth curve analysis, only participants retained in OAT demonstrated significant reductions in daily illicit opioid use when compared to 'no OAT' controls (p < 0.05). Nevertheless, reductions in homelessness (p = 0.070) and increases in difficulty accessing services (p = 0.078) were observed between participants retained in OAT vs. 'no OAT' controls, while reductions in homelessness (p = 0.085) and weekly non-medical prescription opioid use (NMPOU) (p = 0.061) were observed between 'OAT discontinuers' vs. 'no OAT' controls.

CONCLUSIONS

Despite finding that OAT retention was associated with significant reductions in daily illicit opioid use, no significant improvements in other key indicators were observed. This underscores the importance of providing supports alongside OAT to improve treatment outcomes among AYA.

Identifying behaviours for survival and wellness among people who use methamphetamine with opioids in British Columbia: a qualitative study

Background

British Columbia (BC) has been in a state of public health emergency since 2016, due to the unprecedented numbers of fatal and non-fatal drug toxicity (i.e. overdose) events. Methamphetamine detection in illicit drug toxicity deaths increased from 14% in 2012 to 43% in 2020 suggesting a concerning trend of concurrent methamphetamine and opioid use in BC, consistent with rising patterns identified across North America. People who use methamphetamine concurrently with opioids face an elevated risk of harm. This study aimed to identify behaviours for survival and wellness practiced by people who concurrently use methamphetamine and opioids.

Methods

One-on-one semi-structured interviews were conducted by peer research assistants in person and by telephone. Thematic analysis was carried out to identify patterns in behaviours participants described as important to their safety in the context of concurrent use of methamphetamine and opioids.

Results

Participants (n = 22) were distributed across the province with at least four participants from each of the five geographic health regions: 64% self-identified as men, and 50% self-identified as Indigenous. Daily methamphetamine use was reported by 72.7% of participants, and 67.3% reported using alone either often or always. Participants made several considerations and adaptations in order to balance the perceived benefits and risks of their use of methamphetamine with opioids. Two overarching themes were identified to describe how participants adapted their use for survival and wellness. The first was personal safety behaviours which included self-regulation and self-care behaviours. The second was interpersonal safety behaviours which included using alongside peers, and engaging with peer-led services (e.g. community outreach organizations) and public health-led services (e.g. overdose prevention sites) to reduce the risk of harm. Participants identified many gaps in available services to meet their diverse needs.

Conclusions

This manuscript identified diversity in participants’ methamphetamine and opioid use (i.e. frequency, route of administration), and a range of behaviours that were performed to improve wellness and survival while using methamphetamine and opioids. Harm reduction and treatment responses must be robust and adaptable to respond to the diversity of patterns of substance use among people who use methamphetamine and opioids concurrently, so as to not perpetuate harm and leave people behind.

"There are solutions and I think we're still working in the problem": The limitations of decriminalization under the good Samaritan drug overdose act and lessons from an evaluation in British Columbia, Canada

BACKGROUND

Drug prohibition has been associated with increased risk of overdose. However, drug prohibition remains the dominant drug policy, including in Canada with the Controlled Drugs and Substances Act. In 2017, the Good Samaritan Drug Overdose Act (GSDOA) was enacted, to encourage people to contact emergency medical services by providing bystanders at the scene of an overdose with legal protection for simple possession and conditions related to simple possession.

METHODS

We conducted an evaluation of the GSDOA in British Columbia, Canada that included one-on-one interviews with people who use illicit drugs (PWUD), to determine peoples' experiences and perceptions surrounding this form of decriminalization. We present findings from a thematic analysis of 37 interviews.

RESULTS

We identified limitations of the GSDOA at overdose events; key themes and concerns causing PWUD to hesitate to or avoid contacting emergency medical services included drug confiscation, the thin line between simple possession and drug trafficking, and enforcement of other charges and court ordered conditions that are not legally protected by the GSDOA. Moreover, participants discussed the GSDOA as inequitable; benefiting some while excluding PWUD with intersecting marginalized identities.

CONCLUSION

Our findings are pertinent in light of many jurisdictions across the world considering dejure decriminalization, including BC and Vancouver. The GSDOA and associated limitations that emerged in our evaluation can serve to guide jurisdictions implementing or amending dejure decriminalization policies.

Motivations for concurrent use of uppers and downers among people who access harm reduction services in British Columbia, Canada: findings from the 2019 Harm Reduction Client Survey

INTRODUCTION

An increase in crystal methamphetamine (methamphetamine) use during the overdose epidemic is being observed in British Columbia (BC), Canada, and across North America. Concurrent use (ie, using uppers and downers one after the other or together) can increase the risk of fatal and non-fatal opioid overdose.

OBJECTIVES

We investigated motivations for concurrent use of uppers and downers, specifically how (eg, in what order) and why people use concurrently, to identify potential interventions to prevent overdose and other harms.

SETTING AND PARTICIPANTS

The 2019 Harm Reduction Client Survey was administered across 22 harm reduction supply distribution sites in BC (n=621). This thematic analysis examined 307 responses by people who affirmed concurrent use to classify order and reasons for using uppers and downers concurrently.

RESULTS

Of the 307 people who responded 'yes' to concurrent use, 179 (58.3%) used downers then uppers, 76 (24.8%) used uppers then downers and 184 (59.9%) mixed uppers and downers together. Four main reasons for concurrent use emerged: self-medication, availability and preference, drug effects/properties, and financial and life situation. People who mixed drugs together predominantly wanted to achieve desired drug effects/properties, such as a specific high or balancing stimulating and sedating effects.

CONCLUSIONS

The ongoing rise in overdoses in BC is multifactorial, and the recent parallel increases in methamphetamine use and concurrent use with opioids may contribute. Qualitative interviews may further elucidate reasons for concurrent use. Addressing reasons for concurrent use identified in this study through harm reduction strategies and education may affect the rates of overdose morbidity and mortality.

Priorities among effective clinical preventive services in British Columbia, Canada

Background

Despite the long-standing experience of rating the evidence for clinical preventive services, the delivery of effective clinical preventive services in Canada and elsewhere is less than optimal. We outline an approach used in British Columbia to assist in determining which effective clinical preventive services are worth doing.

Methods

We calculated the clinically preventable burden and cost-effectiveness for 28 clinical preventive services that received a ‘strong or conditional (weak) recommendation for’ by the Canadian Task Force on Preventive Health Care or an ‘A’ or ‘B’ rating by the United States Preventive Services Task Force. Clinically preventable burden is the total quality adjusted life years that could be gained if the clinical preventive services were delivered at recommended intervals to a British Columbia birth cohort of 40,000 individuals over the years of life that the service is recommended. Cost-effectiveness is the net cost per quality adjusted life year gained.

Results

Clinical preventive services with the highest population impact and best value for money include services that address tobacco use in adolescents and adults, exclusive breastfeeding, and screening for hypertension and other cardiovascular disease risk factors followed by appropriate pharmaceutical treatment. In addition, alcohol misuse screening and brief counseling, one-time screening for hepatitis C virus infection in British Columbia adults born between 1945 and 1965, and screening for type 2 diabetes approach these high-value clinical preventive services.

Conclusions

These results enable policy makers to say with some confidence what preventive manoeuvres are worth doing but further work is required to determine the best way to deliver these services to all those eligible and to establish what supportive services are required. After all, if a clinical preventive service is worth doing, it is worth doing well.

Factors associated with take-home naloxone kit usage in British Columbia: an analysis of administrative data

BACKGROUND

The British Columbia (BC) Take-Home Naloxone (THN) program provides naloxone to people at risk of experiencing or witnessing an opioid overdose for use in reversing suspected overdose events. This study seeks to examine trends and correlates of individuals obtaining a THN kit in BC between 2017 and 2020.

METHODS

Records of THN kits distributed between 2017 and 2020 were the primary source of data for this analysis. Frequency tables were used to describe characteristics of people obtaining kits from THN sites. Correlates of individuals obtaining a THN kit to replace a previous kit reported as used to reverse an overdose were assessed with multivariate logistic regression.

RESULTS

Between January 1, 2017, and December 31, 2020, 240,606 THN kits were reported distributed by registered sites to members of the public, with 90,011 records indicating that a kit was obtained to replace a previous kit that had been used to reverse an overdose. There was a significant trend in increasing kits reported used by year (p < 0.01). The kit recipient's risk of overdose was a significant predictor of having reported using a THN kit, and the strength of the association was dependent on gender (Male: Adjusted odds ratio (AOR) 5.37 [95% confidence interval (CI) 5.08 - 5.67]; Female: AOR 8.35 [95% CI 7.90 - 8.82]; Trans and gender expansive: AOR 3.68 [95% CI 2.82 - 4.79]).

CONCLUSIONS

Between 2017 and 2020, THN kits were used to reverse tens of thousands of overdose events in BC, with people at risk of overdose (i.e. people who use drugs [PWUD]) having greater odds of using a kit to reverse an overdose than those not at risk. Thus, PWUD are responsible for reversing the vast majority of overdoses. THN kits are being distributed to the people who use them most. However, additional strategies in conjunction with community-based naloxone distribution programs are needed to address the rising number of illicit drug toxicity deaths.

Smoke Gets in the Eye: A systematic review of case reports of ocular complications of crack cocaine use

ISSUES

Use of crack cocaine and associated medical complications persists globally. Some reports in medical literature describe a sight-threatening condition commonly referred to as 'crack eye' or 'crack eye syndrome'. The purpose of this review is to describe what is known about crack eye from case reports in peer-reviewed literature.

APPROACH

A structured search was completed in MEDLINE, TOXLINE, EMBASE, PsychInfo, Scopus and Biomed Central, to collect case reports and case series on corneal complications attributed to crack cocaine smoking.

KEY FINDINGS

Of 111 articles screened, 11 contained case reports or series. Thirty individual cases of 'crack eye' were reported. The majority (63%) of cases had bilateral involvement; 83% of all cases with microbial culture results had corneal infections. Aggressive treatment caused an improvement in 95% of all cases and 23% of all cases were lost to follow up. Of those who received treatment for corneal complications associated with crack cocaine, 22% remained with significant visual impairment (hand motions only) in the affected eye.

IMPLICATIONS

Clinicians should consider crack cocaine involvement in patients presenting with corneal disease without known predisposing factors, and elicit comprehensive drug histories to prevent a reduction in visual acuity.

CONCLUSION

Corneal complications of crack cocaine smoking are caused by a number of synergistic factors, including direct toxicity of crack cocaine vapours to surface cells, impairment of neurogenic support to corneal epithelial integrity, desiccation of the eye surface due to diminished blinking reflex, low level chemical burns and mechanical denudement of surface cells through eye rubbing.

Investigating opioid preference to inform safe supply services: A cross sectional study

BACKGROUND

The drug toxicity crisis continues to be a significant cause of death. Over 24,600 people died from opioid toxicity in Canada over the last 5 years. Safe supply programs are required now more than ever to address the high rate of drug toxicity overdose deaths caused by illicit fentanyl and its analogues. This study aims to identify opioid preferences and associated variables to inform further phases of safe supply program implementation.

METHODS

The Harm Reduction Client Survey, an annual cross-sectional survey of people who use drugs (PWUD), was administered at harm reduction supply distribution sites in BC in October-December 2019. The survey collects information on substance use patterns, associated harms, stigma, and utilization of harm reduction services. Eligibility criteria for survey participation included aged 19 years or older; self-reported substance use of any illicit substance in the past six months, and ability to provide verbal informed consent. We conducted multivariate logistic regression to investigate associations with opioid preference. We used the dichotomized preference for either heroin or fentanyl as an outcome variable. Explanatory variables of interest included: geographic region, urbanicity, gender, age category, Indigenous identity, housing, employment, witnessing or experiencing an overdose, using drugs alone, using drugs at an observed consumption site, injection as preferred mode of use, injecting any drug, frequency of use, and drugs used in last 3 days.

RESULTS

Of the 621 survey participants, 405 reported a preferred opioid; of these 57.8% preferred heroin, 32.8% preferred fentanyl and 9.4% preferred prescription opioids. The proportion of participants who preferred heroin over fentanyl significantly increased with age. The adjusted odds of a participant 50 or older preferring heroin was 6.76 (95% CI: 2.78-16.41, p-value: < 0.01) times the odds of an individual 29 or under. The adjusted odds of an Indigenous participant reporting a preference for heroin compared to fentanyl was 1.75 (95% CI: 1.03-2.98, p-value: 0.04) the odds of a non-Indigenous participant reporting the same. Adjusted odds of heroin preference also differed between geographic regions within British Columbia, Canada.

CONCLUSION

Opioid preference differs by age, geographic area, and Indigenous identity. To create effective safe supply programs, we need to engage PWUD about their drugs of choice.

Association Between Prescription Opioid Therapy for Noncancer Pain and Hepatitis C Virus Seroconversion

IMPORTANCE

Initiation of injection drug use may be more frequent among people dispensed prescription opioid therapy for noncancer pain, potentially increasing the risk of hepatitis C virus (HCV) acquisition.

OBJECTIVE

To assess the association between medically dispensed long-term prescription opioid therapy for noncancer pain and HCV seroconversion among individuals who were initially injection drug use-naive.

DESIGN, SETTING, AND PARTICIPANTS

A population-based, retrospective cohort study of individuals tested for HCV in British Columbia, Canada, with linkage to outpatient pharmacy dispensations, was conducted. Individuals with an initial HCV-negative test result followed by 1 additional test between January 1, 2000, and December 31, 2017, and who had no history of substance use at baseline (first HCV-negative test), were included. Participants were followed up from baseline to the last HCV-negative test or estimated date of seroconversion (midpoint between HCV-positive and the preceding HCV-negative test).

EXPOSURES

Episodes of prescription opioid use for noncancer pain were defined as acute (<90 days) or long-term (≥90 days). Prescription opioid exposure status (long-term vs prescription opioid-naive/acute) was treated as time-varying in survival analyses. In secondary analyses, long-term exposure was stratified by intensity of use (chronic vs. episodic) and by average daily dose in morphine equivalents (MEQ).

MAIN OUTCOMES AND MEASURES

Multivariable Cox regression models were used to assess the association between time-varying prescription opioid status and HCV seroconversion.

RESULTS

A total of 382 478 individuals who had more than 1 HCV test were included, of whom more than half were female (224 373 [58.7%]), born before 1974 (201 944 [52.8%]), and younger than 35 years at baseline (196 298 [53.9%]). Participants were followed up for 2 057 668 person-years and 1947 HCV seroconversions occurred. Of the participants, 41 755 people (10.9%) were exposed to long-term prescription opioid therapy at baseline or during follow-up. The HCV seroconversion rate per 1000 person-years was 0.8 among the individuals who were prescription opioid-naive/acute (1489 of 1947 [76.5%] seroconversions; 0.4% seroconverted within 5 years) and 2.1 with long-term prescription opioid therapy (458 of 1947 [23.5%] seroconversions; 1.1% seroconverted within 5 years). In multivariable analysis, exposure to long-term prescription opioid therapy was associated with a 3.2-fold (95% CI, 2.9-3.6) higher risk of HCV seroconversion (vs prescription opioid-naive/acute). In separate Cox models, long-term chronic use was associated with a 4.7-fold higher risk of HCV seroconversion (vs naive/acute use 95% CI, 3.9-5.8), and long-term higher-dose use (≥90 MEQ) was associated with a 5.1-fold higher risk (vs naive/acute use 95% CI, 3.7-7.1).

CONCLUSIONS AND RELEVANCE

In this cohort study of people with more than 1 HCV test, long-term prescription opioid therapy for noncancer pain was associated with a higher risk of HCV seroconversion among individuals who were injection drug use-naive at baseline or at prescription opioid initiation. These results suggest injection drug use initiation risk is higher among people dispensed long-term therapy and may be useful for informing approaches to identify and prevent HCV infection. These findings should not be used to justify abrupt discontinuation of long-term therapy, which could increase risk of harms.

Risk of cardiovascular diseases in relation to substance use disorders

BACKGROUND

Substance use disorder (SUD) has become increasingly prevalent worldwide, this study investigated the associations of SUD and alcohol, cannabis, opioid, or stimulant use disorder with cardiovascular disease (CVD) and 11 major CVD subtypes.

METHODS

This study was based on a 20% random sample of residents in British Columbia, Canada, who were aged 18 - 80 years at baseline on January 1, 2015. Using linked administrative health data during 2010 - 2014, we identified people with various SUDs and prevalent CVDs at baseline, and examined the cross-sectional associations between SUDs and CVDs. After excluding people with CVDs at baseline, we followed the cohort for 4 years to identify people who developed incident CVDs, and examined the longitudinal associations between SUDs and CVDs.

RESULTS

The cross-sectional analysis at baseline included 778,771 people (mean age 45 years, 50% male), 13,279 (1.7%) had SUD, and 41,573 (5.3%) had prevalent CVD. After adjusting for covariates, people with SUD were 2.7 (95% confidence interval [CI], 2.5 - 2.8) times more likely than people without SUD to have prevalent CVD. The longitudinal analysis included 617,863 people, 17,360 (2.8%) developed incident CVD during the follow-up period. After adjusting for covariates, people with SUD were 1.7 (95% CI, 1.6 - 1.9) times more likely than people without SUD to develop incident CVD. The cross-sectional and longitudinal associations were more pronounced for people with opioid or stimulant use disorder.

CONCLUSIONS

People with SUD are more likely to have prevalent CVD and develop incident CVD compared with people without SUD.