MDMA-assisted therapy is associated with a reduction in chronic pain among people with post-traumatic stress disorder.

Introduction: Increasing evidence demonstrates 3,4-methylenedioxymethamphetamine (MDMA)-assisted therapy (MDMA-AT) may be a safe and effective treatment for post-traumatic stress disorder (PTSD). There is growing interest in MDMA-AT to address a range of other health challenges. Chronic pain and PTSD are frequently comorbid, reciprocally interdependent conditions, though the possible role of MDMA-AT in treating chronic pain remains under-investigated. The present analysis examined the impact of manualized MDMA-AT on chronic pain severity among participants with PTSD who were enrolled in a Phase 2 clinical trial investigating MDMA-AT for PTSD (NCT03282123). Materials and methods: Exploratory data from a subset of participants who completed chronic pain measures (n = 32) were drawn from a Phase 2 open-label study sponsored by the Multidisciplinary Association for Psychedelic Studies (MAPS). Multivariable analysis of variance (ANOVA) was utilized to compare pre- vs. post-treatment Chronic Pain Grade Scale (CPGS) values, adjusting for demographics (age, sex, and ethnicity). K-means clustering was then used to group the sample into three clusters to denote high (n = 9), medium (n = 11), and low (n = 12) baseline pain severity, and the same analysis was repeated for each cluster. Results: Among the 32 participants included in this analysis, 59% (n = 19) were women, 72% (n = 23) were white, and median age was 38 years [interquartile range (IQR) = 31-47]. Overall, 84% (n = 27) reported having pain, and 75% (n = 24) reported disability associated with their pain. Significant reductions in CPGS subscales for pain intensity and disability score, and overall CPGS severity grade were observed among participants in the highest pain cluster (n = 9, p < 0.05), and for pain intensity in the medium pain cluster (n = 11, p < 0.05) post- vs. pre-treatment. Discussion: Findings demonstrate a high prevalence of chronic pain in this sample of people with severe PTSD and that chronic pain scores among medium and high pain subgroups were significantly lower following MDMA-AT. While these data are preliminary, when considered alongside the frequency of comorbid chronic pain and PTSD and promising efficacy of MDMA-AT for treating PTSD, these findings encourage further research exploring the role of MDMA-AT for chronic pain.

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.

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.

Periods of Homelessness Linked to Higher VACS Index Among HIV-Positive People Who Use Drugs.

We sought to evaluate the impact of homelessness on HIV disease progression among people who use unregulated drugs (PWUD) living with HIV and test if this association was mediated by adherence to antiretroviral therapy (ART). We applied general linear mixed-effects modeling to estimate the longitudinal relationship between homelessness and the Veterans Aging Cohort Study (VACS) Index, a validated measure of HIV disease progression that predicts all-cause mortality, among a prospective cohort of PWUD. In a longitudinal model adjusted for ART adherence, homelessness was significantly associated with increased VACS Index scores and 16% of the association was mediated by ART adherence. These findings indicate that homelessness was a significant risk factor for HIV disease progression and this association was marginally mediated by ART adherence. Future studies are needed to quantify the other mechanisms (e.g., food insecurity, mental health) by which homelessness increases mortality risk among PWUD living with HIV.

Inability to access primary care clinics among people who inject drugs in a Canadian health care setting.

OBJECTIVE: To examine the prevalence and correlation of self-reported inability to access community primary care clinics among people who inject drugs (PWID). DESIGN: Self-report questionnaire data. SETTING: Vancouver, BC. PARTICIPANTS: Data were derived from 3 prospective cohort studies of PWID between 2013 and 2016. MAIN OUTCOME MEASURES: Multivariable generalized estimating equations were used to determine prevalence of and reasons for self-reported inability to access primary care, as well as factors associated with inability to access care. RESULTS: Of 1396 eligible participants, including 525 (37.6%) women, 209 (15.0%) persons were unable to access a primary care clinic at some point during the study period. In the multivariable analysis, factors independently associated with inability to access clinics included ever being diagnosed with a mental health disorder (adjusted odds ratio [AOR] = 1.63, 95% CI 1.14 to 2.35), dealing drugs (AOR = 1.60, 95% CI 1.15 to 2.22), using emergency services (AOR = 1.51, 95% CI 1.13 to 2.02), being female (AOR = 1.49, 95% CI 1.08 to 2.08), and testing positive for HIV (AOR = 0.47, 95% CI 0.30 to 0.72) (for all factors, P < .05). CONCLUSION: Specific exposures were linked to challenges in accessing primary care among the sample of PWID, even in a publicly funded health care setting. Notably, models designed for care of people with HIV appear to increase access to primary care among PWID. Further research is needed to determine how to effectively treat accompanying mental illness, how to provide women-centred services, and how to connect people with primary care who would likely otherwise go to the emergency department.

Income generation and the patterning of substance use: A gender-based analysis.

BACKGROUND: Previous research has demonstrated how income-generating activities among marginalized people who use drugs (PWUD)-including employment, income assistance, street-based activities, sex work, and illegal activities-can provide both benefit (e.g., additional income) and harm (e.g., violence, criminalization). However, little is known about gender differences in factors such as drug use patterns that are associated with income-generating activities among PWUD. METHODS: Using data from prospective cohorts of HIV-positive and HIV-negative PWUD in Vancouver, Canada, we conducted exploratory gender-stratified analyses of associations between substance use patterns and income-generating activities, using generalized linear mixed-models. RESULTS: Participants reported income sources as employment (23.4 %), income assistance (88.1 %), street-based activities (24.9 %), sex work (15.2 %), drug dealing (31.5 %), or other illegal activities (13.9 %). GLMM results showed gendered patterns of engagement in specific income-generating activities and some diverging patterns of substance use. For instance, men receiving income assistance were less likely to use opioids (Adjusted odds ratio(AOR) = 0.64; 95 % confidence interval(CI) = 0.50-0.82) and women engaged in sex work were more likely to use crack-cocaine (AOR = 2.74, 95 % CI = 2.22-3.37). However, results reflected primarily converging patterns of substance use between women and men across income-generating activities, particularly for drug dealing and other illegal activities. CONCLUSIONS: Our results suggest that substance use patterns may be more closely associated with income generation context than gender. Given potential harms associated with some income generation activities, results highlight the need for further investigation of the social and structural context of income generation, its intersections with gender and substance use, and the expansion of low-threshold work opportunities.

High-intensity cannabis use and hospitalization: a prospective cohort study of street-involved youth in Vancouver, Canada.

BACKGROUND: There is concern that cannabis use negatively affects vulnerable groups such as youth; however, the relationship between cannabis use and health care utilization has not been well characterized in this population. We longitudinally evaluated the association between daily cannabis use and hospitalization among a prospective cohort of street-involved youth. METHODS: Data were collected from the At-Risk Youth Study (ARYS) in Vancouver, Canada, from September 2005 to May 2015. Participants were interviewed semi-annually and multivariable generalized estimating equation (GEE) logistic regression was used to examine the relationship between daily cannabis use and hospitalization. RESULTS: A total of 1216 participants (31.2% female) were included in this analysis, and 373 (30.7%) individuals reported hospitalization at some point during the study period. In a multivariable GEE analysis, daily cannabis use was not significantly associated with hospitalization (Adjusted Odds Ratio [AOR] = 1.17, 95% Confidence interval [CI] = 0.84, 1.65). We did observe a significant interaction between daily cannabis use and sex (AOR = 0.51, 95% CI = 0.34, 0.77), whereby cannabis use was associated with a decreased odds of hospitalization among males (AOR = 0.60, 95% CI = 0.47, 0.78), yet was not significantly associated with hospitalization among females (AOR = 1.19, 95% CI = 0.84, 1.67). CONCLUSIONS: The finding that daily cannabis use was not associated with hospitalization among street-involved youth is encouraging given the high rates of cannabis use in this population and the expansion of cannabis legalization and regulation. Future studies, however, are warranted to monitor possible changes in the consequences of cannabis use as cannabis legalization and regulation increase internationally.

Effect of alternative income assistance schedules on drug use and drug-related harm: a randomised controlled trial.

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.

Prevalence and longitudinal correlates of recent exposure to fentanyl among HIV-positive people who use unregulated drugs during a community-wide overdose crisis.

The United States and Canada are experiencing an opioid overdose crisis driven largely by exposure to fentanyl (a potent synthetic opioid), with little known about fentanyl exposure among HIV-positive people who use unregulated drugs (PWUD). We sought to estimate the prevalence and correlates of fentanyl exposure among a community-recruited sample derived from a prospective cohort study of HIV-positive PWUD in Vancouver, Canada. Generalized linear mixed-effects analyses were used to identify longitudinal factors associated with a fentanyl-positive urine drug screen test. Between June 2016-November 2017, 456 participants were recruited and contributed 1007 observations. At baseline, 96% of participants were ART-exposed, 72% had an HIV viral load (VL) <50 copies/mL and 21% had a fentanyl-positive test. Longitudinally, fentanyl-positive tests were characterized by: younger participant age (Adjusted Odds Ratio [AOR] = 0.45), recent non-fatal overdose (AOR = 2.30), engagement in opioid agonist therapy (AOR = 1.91), and at least daily heroin injection (AOR = 11.27). CD4+ cell count was negatively associated with fentanyl urine positivity (AOR = 0.92) (all p < 0.05). We identified several risk factors for overdose linked to fentanyl exposure among this sample, although no link with HIV treatment engagement or detectable HIV VL. Innovative strategies are needed to reduce the harmful effects of the contaminated unregulated drug supply experienced by PWUD.

Trust in research physicians as a key dimension of randomized controlled trial participation in clinical addictions research.

Background: In the development of pharmacotherapies for substance use disorders, willingness to participate in randomized controlled trials (RCTs) among people who use drugs (PWUD) is influenced by numerous social and structural factors. Considering the criminalization and stigma experienced by PWUD and range of experiences in healthcare and research, PWUD may vary in their trust of health providers, health research physicians, or medical research processes. We therefore examine associations between trust in these three domains and willingness to participate in a hypothetical RCT for a novel pharmacotherapy for stimulant use among PWUD. Methods: Data were derived from a cross-sectional questionnaire administered to participants using crack and/or cocaine from three cohort studies of PWUD in Vancouver (N = 229). Results: A majority of participants were "definitely" or "probably" willing to participate in an RCT. In multivariable ordinal regression, trust in research physicians was positively associated with willingness to participate, while trust in primary care providers or medical research processes were not significantly associated. Conclusions: This data suggests trust in research physicians plays a role in RCT decision-making among PWUD, while trust in healthcare providers and research processes appears less relevant. These findings highlight opportunities for supporting RCT recruitment by building trust in research physicians.

The Veterans Aging Cohort Study (VACS) Index Predicts Mortality in a Community-recruited Cohort of People With Human Immunodeficiency Virus (HIV) Who Use Illicit Drugs.

The Veterans Aging Cohort Study (VACS) index combines commonly collected clinical biomarkers to estimate human immunodeficiency virus (HIV) disease severity. Among a prospective cohort of people living with HIV who use illicit drugs (PWUD) (n = 948), we found that the VACS index was significantly associated with mortality over a 20-year study period.

Pain and Barriers to Accessing Health Services Among People Who Use Drugs.

BACKGROUND: The opioid overdose crisis underscores the need for health services among people who use drugs (PWUD) with concurrent pain. AIMS: Investigating the effect of pain on barriers to accessing health services among PWUD. DESIGN: Prospective cohort study. SETTINGS: A setting of universal access to no-cost medical care in Vancouver, Canada from June 2014 to May 2016. PARTICIPANTS/SUBJECTS: PWUD who completed at least one study interview. METHODS: Data derived from interviewer-administered questionnaires were used for multivariable generalized linear mixed-effects multiple regression (GLMM) analyses. RESULTS: Among 1,348 PWUD, 469 (34.8%) reported barriers to accessing health services at least once during the study period. The median average pain severity was 3 (IQR: 0-6) out of 10. A dose-response relationship was observed between greater pain and increased odds of reporting barriers to accessing health services (adjusted odds ratio [AOR]: 1.59, 95% confidence interval [CI]: 1.15-2.21, p = .005 for mild versus no pain; AOR: 1.76, 95% CI: 1.30-2.37, p < .001 for moderate versus no pain; AOR: 2.55, 95% CI: 1.92-3.37, p < .001 for severe versus no pain). Common barriers included poor treatment by health professionals, socio-structural barriers such as transportation or mobility, and long wait lists or wait times. CONCLUSIONS: Pain may be a significant risk factor associated with increased barriers to accessing health services among PWUD. Attention to pain management may improve access to health services, and reducing barriers to health services may conversely improve pain management and its related risks and harms.

Greater Pain Severity is Associated with Inability to Access Addiction Treatment Among a Cohort of People Who Use Drugs.

AIM: Given that co-occurring pain is prevalent among people who use drugs (PWUD), we sought to explore the effect of pain severity on accessing addiction treatment. METHODS: Data were derived from two prospective cohort studies of PWUD in Vancouver, Canada from June 2014 to May 2016. Multivariable generalized linear mixed-effects multiple regression (GLMM) analyses were used to investigate the association between average pain severity and self-reported inability to access addiction treatment. RESULTS: Among 1348 PWUD, 136 (10.1%) reported being unable to access addiction treatment at least once over the study period. Individuals who reported being unable to access addiction treatment had a significantly higher median average pain severity score (median=5, IQR=0-7) compared to individuals reporting no inability to access addiction treatment (median=3, IQR=0-6, p=0.038). Greater pain severity was independently associated with higher odds of reporting inability to access addiction treatment (AOR: 1.75, 95%CI: 1.08-2.82 for mild-moderate vs no pain; AOR: 1.98, 95%CI: 1.27-3.09 for moderate-severe vs no pain). CONCLUSION: PWUD with greater pain severity may be at higher risk of being unable to access addiction treatment, or vice versa. While further research is needed to confirm causal associations, these data suggest that there may be underlying pathways or mechanisms through which pain may be associated with access to addiction treatment for PWUD.

Withdrawal-associated injury site pain prevalence and correlates among opioid-using people who inject drugs in Vancouver, Canada.

BACKGROUND: Pain can return temporarily to old injury sites during opioid withdrawal. The prevalence and impact of opioid withdrawal-associated injury site pain (WISP) in various groups is unknown. METHODS: Using data from observational cohorts, we estimated the prevalence and correlates of WISP among opioid-using people who inject drugs (PWID). Between June and December 2015, data on WISP and opioid use behaviours were elicited from participants in three ongoing prospective cohort studies in Vancouver, Canada, who were aged 18 years and older and who self-reported at least daily injection of heroin or non-medical presciption opioids. RESULTS: Among 631 individuals, 276 (43.7 %) had a healed injury (usually pain-free), among whom 112 (40.6 %) experienced WISP, representing 17.7 % of opioid-using PWID interviewed. In a multivariable logistic regression model, WISP was positively associated with having a high school diploma or above (Adjusted Odds Ratio [AOR] = 2.23, 95 % Confidence Interval [CI]: 1.31-3.84), any heroin use in the last six months (AOR = 2.00, 95 % CI: 1.14-3.57), feeling daily pain that required medication (AOR = 2.06, CI: 1.18-3.63), and negatively associated with older age at first drug use (AOR = 0.96, 95 % CI: 0.93-0.99). Among 112 individuals with WISP, 79 (70.5 %) said that having this pain affected their opioid use behaviour, of whom 57 (72.2 %) used more opioids, 19 (24.1 %) avoided opioid withdrawal, while 3 (3.8 %) no longer used opioids to avoid WISP. CONCLUSIONS: WISP is prevalent among PWID with a previous injury, and may alter opioid use patterns. Improved care strategies for WISP are warrented.

Characterising the increasing prevalence of crystal methamphetamine use in Vancouver, Canada, from 2006-2017: A gender-based analysis.

INTRODUCTION: Methamphetamine use is increasing in North America and is associated with numerous negative health effects and social harms. As drug-related harms are often gendered, this study sought to examine the differential impacts of gender on the trends, risk factors and health implications of crystal methamphetamine use among a Canadian cohort of people with high rates of injection polysubstance use. METHODS: Data were collected from two prospective cohorts of people who inject drugs in Vancouver, Canada. We examined trends in reported crystal methamphetamine use from 2006-2017 using the Cochrane-Armitage test for trend. We used multivariable generalised estimating equations, stratified by gender, to determine independent risk factors and health outcomes associated with crystal methamphetamine use. RESULTS: In total, 1984 participants were included in the study, including 694 (35%) women. The prevalence of reported crystal methamphetamine use within the previous 6 months rose from 19% in 2006 to 36% in 2017, with a rise seen in both genders (P < 0.001). Reported crystal methamphetamine use was associated with numerous risk behaviours and drug-related harms in both genders, and in women it was associated with an increase in experiences of sexual violence (adjusted odds ratio 1.64, 95% confidence interval 1.18, 2.27). CONCLUSIONS: These findings demonstrate the rising prevalence of reported crystal methamphetamine use in Vancouver in a cohort with high rates of polysubstance use. This work highlights drug and sex-related risk behaviours associated with crystal methamphetamine use for both genders, and underscores the need to develop strategies to address the growing use of crystal methamphetamine.

Overdose Risk and Acquiring Opioids for Nonmedical Use Exclusively from Physicians in Vancouver, Canada.

BACKGROUND: A primary response to the alarming rise in overdose and mortality due to nonmedical prescription opioid (PO) use has been to restrict opioid prescribing; however, little is known about the relationship between obtaining opioids from a physician and overdose risk among people who use POs nonmedically and illicit street drugs. Objectives: Investigate the relationship between non-fatal overdose and acquiring POs exclusively from physicians for the purposes of engaging in nonmedical PO use. Methods: Data were collected between 2013 and 2016 among participants in two harmonized prospective cohort studies of people who use drugs in Vancouver: the At-Risk Youth Study (ARYS) and the Vancouver Injection Drug Users Study (VIDUS). Analyses were restricted to participants who engaged in nonmedical PO use and used generalized estimating equations. Results: Among 599 participants who used POs nonmedically, 82 (14%) individuals reported acquiring POs exclusively from a physician and 197 (33%) experienced a non-fatal overdose at some point over the study period. Acquiring POs exclusively from physicians was significantly and negatively associated with non-fatal overdose in the bivariate analysis (Odds Ratio = 0.60, 95% Confidence Interval (CI): 0.39-0.94) but not the final multivariate analysis (Adjusted Odds Ratio =0.87, 95% CI: 0.53-1.44). Conclusions: Compared to individuals who acquired POs from friends or the streets, participants who acquired POs exclusively from a physician were not at an increased risk of non-fatal overdose. Although responsible opioid prescribing is an important priority, additional strategies to address nonmedical PO use are urgently needed to reduce overdose and related morbidity and mortality.

Longitudinal patterns of illicit drug use, antiretroviral therapy exposure and plasma HIV-1 RNA viral load among HIV-positive people who use illicit drugs.

OBJECTIVES: HIV-positive people who use illicit drugs (PWUD) experience elevated rates of HIV-associated morbidity and mortality compared with members of other key affected populations. Although suboptimal levels of access and adherence to antiretroviral therapy (ART) are common among HIV-positive PWUD, there is a need for studies investigating the possible biological impacts of noninjection illicit drug use among people living with HIV in real-world settings. METHODS: We accessed data from the ACCESS study, an ongoing prospective cohort of illicit drug users with systematic HIV viral load monitoring in a setting with universal care and ART dispensation records. We used multivariable generalized linear mixed models to estimate the longitudinal associations between noninjection use of crack cocaine, powder cocaine, opioids, methamphetamine, cannabis and alcohol on plasma HIV-1 RNA viral load, adjusted for ART exposure and relevant confounders. RESULTS: Between 2005 and 2018, 843 individuals from the ACCESS cohort were included and contributed to 8698 interviews. At baseline, the mean age was 43 years, 566 (67%) reported male sex and 659 (78%) used crack cocaine in the previous 6 months. In multivariable models adjusted for ART exposure, only crack cocaine use in the last 6 months was found to be significantly associated with higher HIV viral load. CONCLUSION: We observed significantly higher HIV viral load during periods of crack cocaine use independent of ART exposure. Our findings support further research to investigate the possible biological mechanisms of this effect.

Characterizing motivations for cannabis use in a cohort of people who use illicit drugs: A latent class analysis.

BACKGROUND: Cannabis use is common among marginalized people who use illicit drugs (PWUD) but reasons for use remain poorly investigated. We sought to explore how different intentions for cannabis use relate to social, structural, and behavioural factors among PWUD in Vancouver, Canada. METHODS: We used data from cannabis-using participants in two community-recruited prospective cohort studies of PWUD. Using latent class analysis, we identified discrete cannabis-using groups based on self-reported intentions for use. Generalized estimating equations were used to examine correlates of class membership. RESULTS: Between June 2016 and December 2018, 2,686 observations from 897 participants cannabis-using PWUD were analyzed. Four latent classes of cannabis use emerged: Class 1 (31.6%), characterized by non-medical purposes; Class 2 (37.5%), characterized by non-pain therapeutic use (e.g., stress, nausea/loss of appetite, and insomnia); characterized by Class 3 (21.9%) predominantly pain relief; and Class 4 (9.0%), characterized by a wide range of therapeutic uses in addition to pain management, including insomnia, stress, nausea/loss of appetite, and harm reduction. Class-specific structural, substance-, and health-related differences were observed, including indicators of better physical and mental health among the "recreational" class, despite evidence of more structural vulnerabilities (e.g., homelessness, incarceration). CONCLUSIONS: Our findings demonstrate a wide spectrum of motivations for cannabis use among PWUD. We observed important health-related differences between latent classes, demonstrating possible unmet healthcare needs among PWUD reporting therapeutic cannabis use. These findings inform ongoing policy surrounding access to cannabis for harm reduction purposes and applications of medical cannabis for PWUD.

Detecting fentanyl using point-of-care drug checking technologies: A validation study.

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.

The effect of injecting alone on the use of drug checking services among people who inject drugs.

OBJECTIVES: Drug checking services aim to provide people who use drugs with information on the content and purity of their substances as a harm reduction intervention. The objective of this study was to determine the relationship between injecting alone and use of drug checking services in Vancouver, Canada. METHODS: Data were derived from three prospective cohort studies of people who inject drugs (PWID). We conducted bivariable and multivariable logistic regression analysis to estimate the effect of injecting alone on use of drug checking services. RESULTS: Between May 2018 and December 2018, a total of 793 people who inject drugs were included in the study: 579 (73.0%) reported injecting alone and 177 (22.3%) reported use of drug checking services. In a multivariable model adjusted for various confounders (including various sociodemographic variables, drug use patterns, and whether participants had suffered physical attacks/violence), injecting alone was negatively associated with use of drug checking services (Adjusted Odds Ratio = 0.65; 95% Confidence Interval: 0.44-0.97). CONCLUSIONS: We observed a negative association between injecting drugs alone and use of drug checking services, which may be due in part to a number of exogenous factors that prevent people who inject alone from accessing drug checking services (e.g., stigma, location of services). As these individuals are at heightened risk of experiencing overdoses, there is a need to pursue other strategies to reach this group of people who use drugs.