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Opioid agonist treatment (OAT) has been shown to improve certain HIV-related treatment measures among people with HIV (PHIV) with opioid use disorder (OUD). However, there is limited data on the impacts of OAT along the whole HIV cascade of care.Using data from an ongoing cohort of PHIV who use drugs in Vancouver, Canada, we used cumulative link mixed-effects models to estimate the independent effect of OAT on achieving progressive steps in the HIV cascade among participants using unregulated opioids daily, after adjusting for confounders.Between 2005 and 2017, we recruited 639 PHIV regularly using opioids (median age 42 years, 59% male, 56% White), of whom 70% were on OAT at their baseline visit. Engagement in OAT showed a nonsignificant trend with higher linkage to HIV care (adjusted partial proportional odds ratio [APPO] = 1.75, 95% confidence interval [CI]: 0.83-3.69), and significantly higher cumulative odds of successfully achieving subsequent HIV cascade steps: on ART (APPO = 3.85, 95% CI: 2.33-6.37); adherent to ART (APPO = 3.15, 95% CI: 2.15-4.62); and HIV viral suppression (APPO = 2.18, 95% CI: 1.51-3.14).This study found a high level of OAT engagement among PHIV using unregulated opioids and that OAT engagement resulted in significantly increased progression through some of the higher steps of the HIV cascade. While these findings are encouraging, they highlight the need to reach populations off OAT to maximize the clinical and community-level benefits of ART.

In Canada, publicly funded healthcare provides no-cost access to a large but not comprehensive suite of services. Dental care is largely funded by private insurance or patients, creating employment- and income-dependent gaps in care access. Difficulties accessing dental care may be amplified among vulnerable populations, including people who use drugs (PWUD), who may experience greater dental need due to side effects of substance use and health comorbidities, as well as barriers to care. Using data collected between 2014 and 2018 from two ongoing prospective cohort studies of PWUD in Vancouver, Canada, the aim of this study was to explore factors associated with dental care access. Among 1,638 participants, 246 participants (15%) reported never or only occasionally accessing adequate dental care. In generalised linear mixed-effects models, results showed significant negative associations between accessing dental care and using opioids (Adjusted Odds Ratios [AOR] = 0.73, 95% Confidence Interval [CI] = 0.58-0.91), methamphetamine (AOR = 0.75, 95% CI = 0.59-0.95) and cannabis (AOR = 0.78, 95% CI = 0.63-0.97), as well experiencing homelessness (AOR = 0.54, 95% CI = 0.42-0.70) and street-based income generation (AOR = 0.75, 95% CI = 0.59-0.94). There were significant positive associations between adequate dental care and accessing opioid agonist treatment (OAT) for opioid dependence (AOR = 1.36, 95% CI = 1.07-1.72) and receiving income assistance (AOR = 1.70, 95% CI = 1.05-2.77). These results highlight specific substance use patterns and structural exposures that may hinder dental care access, as well as how direct and indirect benefits of income assistance and OAT may improve access. These findings provide support for recent calls to expand healthcare coverage and address dental care inequities.

BackgroundThe COVID-19 pandemic has compounded the longstanding drug poisoning crisis in Canada and the United States (US). Research is needed to understand the contributions of COVID-19 and subsequent infection control measures. We sought to estimate the prevalence of and factors associated with nonfatal overdose among participants in nine prospective cohorts of people who use unregulated drugs (PWUD) in Canada and the US.MethodsData were derived from nine cohorts of PWUD in urban centres in Canada (Vancouver, BC) and the US (Baltimore, MD; Miami, FL; Chicago, IL; Los Angeles, CA) between May, 2020 and April, 2021. Multivariable logistic regression was used to identify factors associated with nonfatal overdose among participants who used unregulated drugs in the past month.ResultsAmong 885 participants (including 253 females), 41 (4.6%) experienced a non-fatal overdose in the past month, and 453 (51.2%) reported being highly impacted day-to-day by the pandemic. In multivariable analyses, people who experienced a non-fatal overdose were more likely to be female (Adjusted Odds Ratio [AOR]=2.18;95% Confidence Interval [CI]=1.10-4.30); unstably housed/homeless (AOR=2.16;95% CI=1.11-4.26); engaged in medications for opioid use disorder (AOR=2.45;95% CI=1.19-4.97); and highly impacted day-to-day (AOR=2.42;95% CI=1.22-5.10).ConclusionOur findings may reflect characteristics of participants who experienced a compounding of vulnerabilities during the pandemic and thus are vulnerable to overdose, including women, those unstably housed/homeless, and those who perceived their daily lives were highly impacted by the pandemic. Multi-level interventions are needed to remediate the vulnerabilities and address the main driver of poisoning crisis.

BackgroundThis study examines individual-level factors associated with avoiding two important health services for people who use drugs-medications for treatment of opioid use disorder and syringe service programs-during the first year of the COVID-19 pandemic.MethodsData come from two subsamples of people who use drugs who were active participants in one of nine cohort studies in Vancouver, British Columbia; Baltimore, Maryland; Los Angeles, California; Chicago, Illinois; and Miami, Florida. Participants were interviewed remotely about COVID-19-associated disruptions to healthcare. We estimated the association of demographic, social, and health factors with each outcome using logistic regression among 702 participants (medication analysis) and 304 participants (syringe service analysis.) Analyses were repeated, stratified by city of residence, to examine geographic variation in risk.ResultsThere were large differences between cities in the prevalence of avoiding picking up medications for opioid use disorder, with almost no avoidance in Vancouver (3%) and nearly universal avoidance in Los Angeles, Chicago, and Miami (>90%). After accounting for between-city differences, no individual factors were associated with avoiding picking up medications. The only factor significantly associated with avoiding syringe service programs was higher levels of self-reported worry about COVID-19.ConclusionDuring the first year of the COVID-19 pandemic, geographic differences in service and policy contexts likely influenced avoidance of health and harm reduction services by people who use drugs in the United States and Canada more than individual differences between people.

Summary Background The synchronised monthly disbursement of income assistance, whereby all recipients are paid on the same day, has been associated with increases in illicit drug use and serious associated harms. This phenomenon is often referred to as the cheque effect. Because payment variability can affect consumption patterns, this study aimed to assess whether these harms could be mitigated through a structural intervention that varied income assistance payment timing and frequency. Methods This randomised, parallel group trial was done in Vancouver, Canada, and enrolled recipients of income assistance whose drug use increased around payment days. The recipients were randomly assigned 1:2:2 to a control group that received monthly synchronised income assistance payments on government payment days, a staggered group in which participants received single desynchronised monthly income assistance payments, or a split and staggered group in which participants received desynchronised income assistance payments split into two instalments per month, 2 weeks apart, for six monthly payment cycles. Desynchronised payments in the intervention groups were made on individual payment days outside the week of the standard government schedules. Randomisation was through a pre-established stratified block procedure. Investigators and statisticians were masked to group allocation, but participants and front-line staff were not. Complete final results are reported after scheduled interim analyses and the resulting early stoppage of recruitment. Under intention-to-treat specifications, generalised linear mixed models were used to analyse the primary outcome, which was escalations in drug use, predefined as a 40% increase in at least one of: use frequency; use quantity; or number of substances used during the 3 days after government payments. Secondary analyses examined analogous drug use outcomes coinciding with individual payments as well as exposure to violence. This trial is registered with ClinicalTrials.gov , NCT02457949 . Findings Between Oct 27, 2015, and Jan 2, 2019, 45 participants were enrolled to the control group, 72 to the staggered group, and 77 to the split and staggered group. Intention-to-treat analyses showed a significantly reduced likelihood of increased drug use coinciding with government payment days, relative to the control group, in the staggered (adjusted odds ratio 0·38, 95% CI 0·20–0·74; p=0·0044) and split and staggered (0·44, 0·23–0·83; p=0·012) groups. Findings were consistent in the secondary analyses of drug use coinciding with individual payment days (staggered group 0·50, 0·27–0·96, p=0·036; split and staggered group 0·49, 0·26–0·94, p=0·030). However, secondary outcome analyses of exposure to violence showed increased harm in the staggered group compared with the control group (2·71, 1·06–6·91, p=0·037). Additionally, 51 individuals had a severe or life-threatening adverse event and there were six deaths, none of which was directly attributed to study participation. Interpretation Complex results indicate the potential for modified income assistance payment schedules to mitigate escalations in drug use, provided measures to address unintended harms are also undertaken. Additional research is needed to clarify whether desynchronised schedules produce other unanticipated consequences and if additional measures could mitigate these harms. Funding Canadian Institutes of Health Research, Providence Health Care Research Institute, Peter Wall Institute for Advanced Research, Michael Smith Foundation for Health Research.

Background The ongoing opioid overdose crisis is driven largely by exposure to illicitly-manufactured fentanyl. Preliminary observational and experimental research suggests that cannabis could potentially play a role in reducing use of prescription opioids among individuals with chronic pain. However, there is limited data on the effects of cannabis on illicit opioid consumption, particularly fentanyl, especially among individuals on opioid agonist therapy (OAT). We sought to assess the longitudinal association between cannabis use and exposure to fentanyl among people on OAT. Methods Data were drawn from two community-recruited prospective cohorts of people who use drugs in Vancouver, Canada. We used generalized linear mixed-effects modeling, adjusted by relevant confounders, to investigate the relationship between cannabis use and recent fentanyl exposure (both assessed by urine drug testing) among participants on OAT between 2016 and 2018. Results Among the 819 participants on OAT who contributed 1989 observations over the study period, fentanyl exposure was common. At the baseline interview, fentanyl was detected in a majority of participants (431, 53 %), with lower prevalence among individuals with urine drug tests positive for tetrahydrocannabinol (47 vs. 56 %, p = 0.028). Over all study interviews, cannabis use was independently associated with reduced likelihood of being recently exposed to fentanyl (Adjusted Prevalence Ratio = 0.91, 95 % Confidence Interval: 0.83 – 0.99). Conclusions Participants on OAT using cannabis had significantly lower risk of being exposed to fentanyl. Our findings reinforce the need for experimental trials to investigate the potential benefits and risks of controlled cannabinoid administration for people on OAT.

Alzheimer's disease (AD) is a chronic neurodegenerative disease that causes memory loss and decline in cognitive abilities. AD is the sixth leading cause of death in the United States, affecting an estimated 5 million Americans. To assess the association between multiple genetic variants and multiple measurements of structural changes in the brain a recent study of AD used a multivariate measure of linear dependence, the RV coefficient. The authors decomposed the RV coefficient into contributions from individual variants and displayed these contributions graphically. We investigate the properties of such a `contribution plot' in terms of an underlying linear model, and discuss estimation of the components of the plot when the correlation signal may be sparse. The contribution plot is applied to simulated data and to genomic and brain imaging data from the Alzheimer's Disease Neuroimaging Initiative., Comment: 20 pages, 8 figures

Objectives Point-of-care drug checking services, wherein individuals can check the content and purity of their drugs, have emerged as a public health intervention to address the fentanyl crisis; however, there have been no rigorous evaluations of the technologies against reference standard laboratory techniques. Methods Two point-of-care technologies, fentanyl immunoassay strips and Fourier-Transform Infrared (FTIR) spectroscopy, were implemented at two supervised injection sites in Vancouver, Canada. We calculated sensitivity, specificity, and false negative rate for both testing methods as compared to a laboratory reference standard. Results Between October 2017 and 2018, 331 samples were sent for confirmatory testing. Immunoassay strips had a sensitivity of 87.5% and specificity of 95.2%, with a false negative rate of 12.5%. FTIR spectroscopy had a sensitivity of 72.1% and specificity of 99.0%, with a false negative rate of 27.9%. Conclusion As expected, while FTIR spectroscopy can quantify concentrations on a wide array of compounds, it can only do so above the detection limit. Using FTIR spectroscopy and immunoassay strips in combination has the potential to offset the limitations of each technology when used alone.