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.

Document d'orientation sur la distribution et l'utilisation de trousses de naloxone à emporter par les intervenants et intervenantes communautaires en cas de surdose au Canada.

CONTEXTE: La toxicité croissante des opioïdes dans le marché illicite des drogues a fait exploser le nombre de surdoses au Canada et ailleurs dans le monde; le programme de naloxone à emporter (NàE) est une intervention fondée sur des données probantes qui consiste à distribuer des trousses contenant de la naloxone aux membres de la communauté susceptibles d'être témoins d'une surdose. L'objectif du présent document d'orientation est de formuler des recommandations stratégiques à l'intention des programmes fédéraux, provinciaux et territoriaux de NàE, en s'appuyant sur des données probantes issues de la documentation scientifique, de la littérature grise et des communautés, à la lumière de 11 années de distribution de NàE au Canada. MÉTHODES : Le groupe d'élaboration des documents d'orientation sur la naloxone, une équipe multidisciplinaire composée de personnes ayant une expertise et une expérience vécue en matière de toxicomanie, a appliqué l'outil AGREE II (Appraisal of Guidelines for Research & Evaluation) afin d'éclairer l'élaboration du présent document d'orientation. En vue de l'élaboration de nos recommandations, nous avons procédé entre décembre 2021 et septembre 2022 à une revue systématique de tous les types d'ouvrages dans le but de recueillir les données probantes publiées, ainsi que les données probantes et l'expertise issues de la communauté. Nous avons sollicité des commentaires sur nos recommandations préliminaires par le biais d'un comité de révision externe et d'un processus de participation du public. Le projet a été financé par les Instituts de recherche en santé du Canada dans le cadre de l'Initiative canadienne de recherche sur l'abus de substances (ICRAS). Nous avons appliqué les principes du Réseau international en matière de lignes directrices (Guidelines International Network) pour gérer les intérêts concurrents. RECOMMANDATIONS: Les données probantes existantes issues de la documentation sur la NàE étaient de faible qualité. Pour élaborer nos recommandations, nous avons incorporé des données probantes tirées de la documentation scientifique et de la littérature grise, ainsi que l'expertise de la communauté. Nos recommandations portent sur 3 volets : les voies d'administration de la naloxone, le contenu des trousses de NàE et les interventions en cas de situations de surdose. Les trousses distribuées par les programmes de naloxone à emporter doivent offrir le choix entre les préparations intramusculaire et intranasale. Le contenu recommandé de la trousse comprend la naloxone, un dispositif d'administration de la naloxone, un équipement de protection individuelle, des instructions et un étui de transport. Les intervenants et intervenantes communautaires formés à la réponse aux surdoses doivent prioriser la respiration artificielle en cas de dépression respiratoire, et la réanimation cardiorespiratoire (RCR) conventionnelle en cas d'arrêt cardiaque, entre autres interventions. INTERPRÉTATION : Ce projet d'élaboration d'un document d'orientation vise à guider les programmes de NàE au Canada dans un contexte où les données probantes publiées sont rares; les recommandations ont été élaborées en collaboration avec diverses parties prenantes.

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.

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.

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.

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.

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.

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.