Methadone maintenance therapy decreases the rate of antiretroviral therapy discontinuation among HIV-positive illicit drug users

We sought to examine whether methadone maintenance therapy (MMT) decreased rates of antiretroviral therapy (ART) discontinuation and was associated with plasma HIV RNA responses among a cohort of illicit drug users. Cumulative ART discontinuation rates were estimated using Kaplan-Meier methods and factors independently associated with ART discontinuation were identified using Cox proportional hazards regression. Engagement in MMT was negatively and independently associated with ART discontinuation [Adjusted Relative Hazard = 0.67 (95 % CI 0.54-0.83); p < 0.001]. Among participants receiving ART and MMT, 81.6 % of plasma HIV-1 RNA assessments were <500 copies/mL, while 65.81 % of HIV-1 RNA assessments among those prescribed ART without MMT were <500 copies/mL (p < 0.001). These results demonstrate that engagement in MMT conferred a protective benefit against ART discontinuation and was associated with a significant increase in plasma HIV RNA suppression among HIV-infected opioid-dependent drug users.

Elimination of HIV transmission through novel and established prevention strategies among people who inject drugs

Despite the effectiveness of existing HIV prevention strategies for people who inject drugs (PWID), uncontrolled outbreaks of HIV among this group are common and occur around the world. In this Review, we summarise recent evidence for novel and established HIV prevention approaches to eliminate HIV transmission among PWID. Effective HIV prevention strategies include mobile needle and syringe programmes, pre-exposure prophylaxis, supervised injection facilities, and, to a lesser extent, some behavioural interventions. Studies have also shown the cost-effectiveness of long-standing HIV prevention strategies including needle and syringe programmes, opioid agonist therapy, and antiretroviral therapy for prevention. Although each individual intervention can reduce the risk of HIV acquisition among PWID, there is a consensus that a combination of approaches is required to achieve substantial and durable reductions in HIV transmission. Unfortunately, in many settings, the implementation of these interventions is often limited by public and political opposition that manifests as structural barriers to HIV prevention, such as the criminalisation of drug use. Given that there is ample evidence showing the effectiveness of several HIV prevention methods, social and political advocacy will be needed to overcome these barriers and integrate innovative HIV prevention approaches with addiction science to create effective drug policies.

Empirical evaluation of the Q-Genie tool: a protocol for assessment of effectiveness

INTRODUCTION

Meta-analyses of genetic association studies are affected by biases and quality shortcomings of the individual studies. We previously developed and validated a risk of bias tool for use in systematic reviews of genetic association studies. The present study describes a larger empirical evaluation of the Q-Genie tool.

METHODS AND ANALYSIS

MEDLINE, Embase, Global Health and the Human Genome Epidemiology Network will be searched for published meta-analyses of genetic association studies. Twelve reviewers in pairs will apply the Q-Genie tool to all studies in included meta-analyses. The Q-Genie will then be evaluated on its ability to (i) increase precision after exclusion of low quality studies, (ii) decrease heterogeneity after exclusion of low quality studies and (iii) good agreement with experts on quality rating by Q-Genie. A qualitative assessment of the tool will also be conducted using structured questionnaires.

DISCUSSION

This systematic review will quantitatively and qualitatively assess the Q-Genie's ability to identify poor quality genetic association studies. This information will inform the selection of studies for inclusion in meta-analyses, conduct sensitivity analyses and perform metaregression. Results of this study will strengthen our confidence in estimates of the effect of a gene on an outcome from meta-analyses, ultimately bringing us closer to deliver on the promise of personalised medicine.

ETHICS AND DISSEMINATION

An updated Q-Genie tool will be made available from the Population Genomics Program website and the results will be submitted for a peer-reviewed publication.

Cannabis use is associated with lower rates of initiation of injection drug use among street-involved youth: A longitudinal analysis

INTRODUCTION AND AIMS

Street-involved youth are known to be at elevated risk of initiating injection drug use. However, the impact of so-called 'gateway' drugs, such as cannabis, on injection initiation is unknown. The objective of this study was to examine the association between cannabis use and initiation of injection drug use among a prospective cohort of street-involved youth in Vancouver, Canada.

DESIGN AND METHODS

Data for this study were collected from the At-Risk Youth Study. From September 2005 to May 2015, participants aged 14-26 who reported illicit drug use were recruited into this open prospective cohort study. An extended Cox regression model with time-updated covariates was used to identify factors independently associated with injection initiation.

RESULTS

During the study period, 481 street-involved youth were included in this study. Of these, 228 (47.4%) reported at least daily cannabis use, and 103 (21.4%) initiated injection drug use. In a multivariable analysis, ≥daily cannabis use was associated with slower rates of injection initiation (adjusted relative hazard 0.66, 95% confidence interval 0.45-0.98; P = 0.038). Sub-analyses revealed that cannabis use was negatively associated with initiation of injection stimulants but not initiation of injection opioids.

DISCUSSION AND CONCLUSIONS

Given the expansion of cannabis legalisation throughout North America, it is encouraging that cannabis use was associated with slower time to initiation of injection drug use in this cohort. This finding challenges the view of cannabis as a gateway substance that precipitates the progression to using harder and more addictive drugs.

Use of North America's first medically supervised safer injecting facility among HIV-positive injection drug users

The objective of this study was to examine supervised injecting facility (SIF) use among a cohort of 395 HIV-positive injection drug users (IDUs) in Vancouver, Canada. The correlates of SIF use were identified using generalized estimating equation analyses. In multivariate analyses, frequent SIF use was associated with homelessness (adjusted odds ratio [AOR] = 1.90), daily heroin injection (AOR = 1.56), and daily cocaine injection (AOR = 1.59). The reasons given for not using the SIF included a preference for injecting at home and already having a safe place to inject. The SIF services most commonly used were needle exchange and nursing services. The SIF appears to have attracted a high-risk subpopulation of HIV-positive IDUs; this coverage perhaps could be extended with the addition of HIV-specific services such as disease monitoring and the provision of antiretroviral therapy.

Incidence and predictors of mental health disorder diagnoses among people who inject drugs in a Canadian setting

INTRODUCTION AND AIMS

Limited attention has been given to the predictors of mental health diagnoses among people who inject drugs (PWID) in community settings. Therefore, we sought to longitudinally examine the prevalence, incidence and predictors of mental disorder diagnosis among a community-recruited cohort of PWID.

DESIGN AND METHODS

Data were derived from two prospective cohort studies of PWID (VIDUS and ACCESS) in Vancouver, Canada between December 2005 and May 2015. We used multivariable extended Cox regression to identify factors independently associated with self-reported mental disorder diagnosis during follow-up among those without a history of such diagnoses at baseline.

RESULTS

Among the 923 participants who did not report a mental disorder at baseline, 206 (22.3%) reported a first diagnosis of a mental disorder during follow-up for an incidence density of 4.29 [95% confidence interval (CI) 3.72-4.91] per 100 person-years. In the multivariable analysis, female sex [adjusted hazards ratio (AHR) = 1.74, 95% CI 1.29-2.33], experiencing non-fatal overdose (AHR = 2.33, 95% CI 1.38-3.94), accessing any drug or alcohol treatment (AHR = 1.68, 95% CI 1.24-2.27), accessing any community health or social services (AHR = 1.53, 95% CI 1.02-2.28) and experiencing violence (AHR = 1.60, 95% CI 1.12-2.29) were independently associated with a mental disorder diagnosis at follow-up.

DISCUSSION AND CONCLUSIONS

We observed a high prevalence and incidence of mental disorders among our community-recruited sample of PWID. The validity and implication of these diagnoses for key substance use and public health outcomes are an urgent priority.

Revisiting the evolutionary origins of obesity: lazy versus peppy-thrifty genotype hypothesis

The recent global obesity epidemic is attributed to major societal and environmental changes, such as excessive energy intake and sedentary lifestyle. However, exposure to 'obesogenic' environments does not necessarily result in obesity at the individual level, as 40-75% of body mass index variation in population is attributed to genetic differences. The thrifty genotype theory posits that genetic variants promoting efficient food sequestering and optimal deposition of fat during periods of food abundance were evolutionarily advantageous for the early hunter-gatherer and were positively selected. However, the thrifty genotype is likely too simplistic and fails to provide a justification for the complex distribution of obesity predisposing gene variants and for the broad range of body mass index observed in diverse ethnic groups. This review proposes that gene pleiotropy may better account for the variability in the distribution of obesity susceptibility alleles across modern populations. We outline the lazy-thrifty versus peppy-thrifty genotype hypothesis and detail the body of evidence in the literature in support of this novel concept. Future population genetics and mathematical modelling studies that account for pleiotropy may further improve our understanding of the evolutionary origins of the current obesity epidemic.

Frequent Cannabis Use and Cessation of Injection of Opioids, Vancouver, Canada, 2005-2018

Objectives. To evaluate the impact of frequent cannabis use on injection cessation and injection relapse among people who inject drugs (PWID).Methods. Three prospective cohorts of PWID from Vancouver, Canada, provided the data for these analyses. We used extended Cox regression analysis with time-updated covariates to analyze the association between cannabis use and injection cessation and injection relapse.Results. Between 2005 and 2018, at-least-daily cannabis use was associated with swifter rates of injection cessation (adjusted hazard ratio [AHR] = 1.16; 95% confidence interval [CI] = 1.03, 1.30). A subanalysis revealed that this association was only significant for opioid injection cessation (AHR = 1.26; 95% CI = 1.12, 1.41). At-least-daily cannabis use was not significantly associated with injection relapse (AHR = 1.08; 95% CI = 0.95, 1.23).Conclusions. We observed that at-least-daily cannabis use was associated with a 16% increase in the hazard rate of injection cessation, and this effect was restricted to the cessation of injection opioids. This finding is encouraging given the uncertainty surrounding the impact of cannabis policies on PWID during the ongoing opioid overdose crisis in many settings in the United States and Canada.

Ranking evidence in substance use and addiction

Evidence-based medicine has consistently prized the epistemological value of randomized-controlled trials (RCTs) owing to their methodological advantages over alternative designs such as observational studies. However, there are limitations to RCTs that hinder their ability to study chronic and dynamic conditions such as substance use and addiction. For these conditions, observational studies may provide superior evidence based on methodological and practical strengths. Assuming epistemic superiority of RCTs has led to an inappropriate devaluation of other study designs and the findings they support, including support for harm reduction services, especially needle exchange programs and supervised injection facilities. The value offered by observational studies should be reflected in evidence-based medicine by allowing more flexibility in evidence hierarchies that presume methodological superiority of RCTs. Despite the popularity of evidence ranking systems and hierarchies, nothing should replace critical appraisal of study methodology and examining the suitability of applying a given study design to a specific research question.

Adiponectin is associated with cardio-metabolic traits in Mexican children

The adipocyte-derived adiponectin hormone bridges obesity and its cardio-metabolic complications. Genetic variants at the ADIPOQ locus, in ADIPOR1, and ADIPOR2 have been associated with adiponectin concentrations and cardio-metabolic complications in diverse ethnicities. However, no studies have examined these associations in Mexican children. We recruited 1 457 Mexican children from Mexico City. Six genetic variants in or near ADIPOQ (rs182052, rs2241766, rs266729, rs822393), ADIPOR1 (rs10920533), and ADIPOR2 (rs11061971) were genotyped. Associations between serum adiponectin, genetic variants, and cardio-metabolic traits were assessed using linear and logistic regressions adjusted for age, sex, and recruitment center. Serum adiponectin concentration was negatively associated with body mass index, waist to hip ratio, low-density lipoprotein cholesterol, total cholesterol, triglycerides, fasting glucose, fasting insulin, homeostatic model assessment of insulin resistance, dyslipidemia and overweight/obesity status (7.76 × 10⁻⁴⁰ ≤ p ≤ 3.00 × 10⁻³). No significant associations between genetic variants in ADIPOQ, ADIPOR1, and ADIPOR2 and serum adiponectin concentration were identified (all p ≥ 0.30). No significant associations between the six genetic variants and cardio-metabolic traits were observed after Bonferroni correction (all p < 6.9 × 10⁻⁴). Our study suggests strong associations between circulating adiponectin concentration and cardio-metabolic traits in Mexican children.

Increasing diversion of methadone in Vancouver, Canada, 2005-2015

BACKGROUND AND AIM

Although methadone, an opioid agonist, has been an effective medication used to treat opioid use disorder for over 40years, recent studies have found that methadone was identified in more than a quarter of prescription opioid-related deaths among people who use illicit drugs in Vancouver, Canada. Thus, we sought to longitudinally examine the availability of diverted methadone among people who inject drugs (PWID).

DESIGN AND METHODS

Data were collected from three prospective cohorts of PWID in Vancouver, Canada between December 2005 and May 2015. Multivariable generalized estimating equation logistic regression was used to identify temporal trends in the immediate availability of diverted methadone (defined as the ability to acquire illicit methadone in <10min).

RESULTS

A total of 2092 participants, including 727 (34.8%) women, were included in the present study. In the multivariable analyses after adjusting for a range of potential confounders, later calendar year (adjusted odds ratio [AOR]=1.21 per year; 95% confidence interval [CI]: 1.19-1.23) was independently and positively associated with reporting immediate availability of diverted methadone.

CONCLUSIONS

We observed a significant increase in the reported availability of diverted methadone among PWID over a ten-year follow-up period. Further research is needed to identify strategies to limit methadone diversion and assess the impact of alternative medications that are equally effective but safer, such as buprenorphine/naloxone.

Prevalence and correlates of selling illicit cannabis among people who use drugs in Vancouver, Canada: A ten-year prospective cohort study

BACKGROUND

The illicit selling and use of cannabis is prevalent among marginalized people who use illicit drugs (PWUD). Given that participation in illicit drug markets has been previously associated with a range of health and social harms, we sought to examine the predictors of selling cannabis among PWUD in Vancouver, Canada, a setting with a de facto legalized cannabis market, on the eve of the planned implementation of legalized non-medical cannabis including measures to regulate the existing illicit market.

METHODS

Multivariable generalized estimating equations (GEE) logistic regression was used to analyze longitudinal factors associated with selling illicit cannabis among three prospective cohorts of PWUD between September 2005 and May 2015.

RESULTS

Among the 3258 participants included in this study, 328 (10.1%) reported selling illicit cannabis at baseline, and 46 (5.1%) initiated cannabis selling over the study period. In the multivariable analysis of the whole sample, factors significantly associated with selling cannabis included cannabis use (Adjusted Odds Ratio [AOR] = 4.05), dealing other drugs (AOR = 3.87), being male (AOR = 1.83), experiencing violence (AOR = 1.40), non-medical prescription opioid use (AOR = 1.32), non-custodial involvement in the criminal justice system (AOR = 1.31), being stopped by police (AOR = 1.30), crack use (AOR = 1.25), homelessness (AOR = 1.23), age (AOR = 0.96 per year) and participation in sex work (AOR = 0.67) (all p < 0.05). The subanalyses indicated that dealing drugs other than cannabis, cannabis use, and non-custodial involvement in the criminal justice system were the only factors significantly associated with selling cannabis in all four subgroups.

CONCLUSION

These findings support existing evidence indicating that selling illicit cannabis is often a survival-driven strategy to support the basic needs and substance use of some PWUD. Our findings suggest jurisdictions with planned or impending cannabis legalization and regulation should consider the vulnerability of PWUD when seeking to eradicate illicit cannabis markets, for example, in setting criminal penalties for selling cannabis outside of regulatory frameworks.

Rationale and design of GENEiUS: a prospective observational study on the genetic and environmental determinants of body mass index evolution in Canadian undergraduate students

INTRODUCTION

Obesity is a global epidemic and is a risk factor for developing other comorbidities. Young adulthood is a critical period for body weight change and establishing healthy lifestyle behaviours. The 'Freshman 15' suggests that undergraduate students gain 15 lbs (6.8 kg) during their first year of university, although evidence estimates a more modest weight gain of approximately 3-5 lbs (1.4-2.3 kg). Previous studies have only investigated weight change in the first year and do not study potential risk factors. Genetic and EnviroNmental Effects on weight in University Students (GENEiUS) is a prospective observational study which will investigate the environmental and biological determinants of weight change in undergraduate students over 4 years.

METHODS AND ANALYSIS

The GENEiUS study will recruit 2500 multiethnic undergraduates aged 17-25 years at McMaster University at the start of their first year and will follow them every 6 months for 4 years. Primary outcomes are obesity traits: body mass index, waist circumference, waist-to-hip ratio, body fat mass and body fat percentage. The contribution of well-established and novel genetic variants for obesity traits and heritability values will be derived from whole-genome single-nucleotide polymorphism genotyping arrays. Civil status, age, sex, ethnicity, length of residence in Canada, religiosity, energy intake, physical activity, exercise motivation, electronic screen time, sleep patterns, history of assault, smoking status, alcohol consumption, medication and drug use, stress, impulsivity, body image perception, self-esteem, anxiety, eating disorders and depression will be investigated for their effect on obesity traits. The findings of the GENEiUS study will be used to help design obesity prevention programme in North American universities with multiethnic populations.

ETHICS AND DISSEMINATION

Ethical approval of the study protocol has been obtained from the Hamilton Integrated Research Ethics Board. Study results will be disseminated through scientific publications, scholarly meetings, and collaborative meetings with university administration and student groups.

Cannabis use to manage opioid cravings among people who use unregulated opioids during a drug toxicity crisis

BACKGROUND

Accumulating evidence has indicated that cannabis substitution is often used as a harm reduction strategy among people who use unregulated opioids (PWUO) and people living with chronic pain. We sought to investigate the association between cannabis use to manage opioid cravings and self-reported changes in opioid use among structurally marginalized PWUO.

METHODS

The data were collected from a cross-sectional questionnaire administered to PWUO in Vancouver, Canada. Binary logistic regression was used to analyze the association between cannabis use to manage opioid cravings and self-reported changes in unregulated opioid use.

RESULTS

A total of 205 people who use cannabis and opioids were enrolled in the present study from December 2019 to November 2021. Cannabis use to manage opioid cravings was reported by 118 (57.6%) participants. In the multivariable analysis, cannabis use to manage opioid cravings (adjusted Odds Ratio [aOR] = 2.13, 95% confidence interval [CI]: 1.07, 4.27) was significantly associated with self-reported reductions in opioid use. In the sub-analyses of pain, cannabis use to manage opioid cravings was only associated with self-assessed reductions in opioid use among people living with moderate to severe pain (aOR = 4.44, 95% CI: 1.52, 12.97). In the sub-analyses of males and females, cannabis use to manage opioid cravings was only associated with self-assessed reductions in opioid use among females (aOR = 8.19, 95% CI: 1.20, 55.81).

CONCLUSIONS

These findings indicate that cannabis use to manage opioid cravings is a prevalent motivation for cannabis use among PWUO and is associated with self-assessed reductions in opioid use during periods of cannabis use. Increasing the accessibility of cannabis products for therapeutic use may be a useful supplementary strategy to mitigate exposure to unregulated opioids and associated harm during the ongoing drug toxicity crisis.

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.

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.

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.

Frequent Cannabis Use Is Negatively Associated with Frequency of Injection Drug Use Among People Who Inject Drugs in a Canadian Setting

Objectives: High levels of morbidity and mortality associated with injection drug use continue to represent a significant public health challenge in many settings worldwide. Previous studies have shown an association between cannabis use and decreased risk of some drug-related harms. We sought to evaluate the association between high-intensity cannabis use and the frequency of injection drug use among people who inject drugs (PWID). Methods: The data for this analysis were collected from three prospective cohorts of PWID in Vancouver, Canada, between September 2005 and May 2018. Generalized linear mixed-effects models were used to analyze the association between daily cannabis use and the frequency of injecting illegal drugs (i.e., self-reported average number of injections per month). Results: Among the 2,619 active PWID, the frequency of injection drug use was significantly lower among people who use cannabis daily compared with people who use it less than daily (adjusted odds ratio [AOR]=0.84, 95% confidence interval [CI]: 0.73-0.95). Sub-analyses indicated that this effect was restricted to the frequency of illegal opioid injection (AOR=0.78, 95% CI: 0.68-0.90); the association between daily cannabis use and the frequency of illegal stimulant injection was not significant (AOR=1.08, 95% CI 0.93-1.25). Discussion: The findings from these prospective cohorts suggest that people who use cannabis daily were less likely to report daily injection of illegal drugs compared with people who use it less than daily. These results suggest the potential value of conducting experimental research to test whether controlled administration of cannabinoids impacts the frequency of illegal opioid injection among PWID.

Experiencing homelessness and progression through the HIV cascade of care among people who use drugs

OBJECTIVE

To investigate the longitudinal association between periods of homelessness and progression through the HIV cascade of care among people who use drugs (PWUD) with universal access to no-cost HIV treatment and care.

DESIGN

Prospective cohort study.

METHODS

Data were analysed from the ACCESS study, including systematic HIV clinical monitoring and a confidential linkage to comprehensive antiretroviral therapy (ART) dispensation records. We used cumulative link mixed-effects models to estimate the longitudinal relationship between periods of homelessness and progression though the HIV cascade of care.

RESULTS

Between 2005 and 2019, 947 people living with HIV were enrolled in the ACCESS study and 304 (32.1%) reported being homeless at baseline. Homelessness was negatively associated with overall progression through the HIV cascade of care [adjusted partial proportional odds ratio (APPO) = 0.56, 95% confidence interval (CI): 0.49-0.63]. Homelessness was significantly associated with lower odds of progressing to each subsequent stage of the HIV care cascade, with the exception of initial linkage to care.

CONCLUSIONS

Homelessness was associated with a 44% decrease in the odds of overall progression through the HIV cascade of care, and a 41-54% decrease in the odds of receiving ART, being adherent to ART and achieving viral load suppression. These findings support calls for the integration of services to address intersecting challenges of HIV, substance use and homelessness among marginalized populations such as PWUD.

Barriers and facilitators to the implementation of an early intervention in psychosis service in three demonstration sites in Ireland

BACKGROUND

Programmes for early intervention (EIP) in psychosis for people experiencing a first episode of psychosis (FEP) have been found to be both clinically and cost effective. Following the publication of a new EIP model of care (MoC) in Ireland, the aim of this research is to describe how people participated in and responded to the MoC including service users, family members, HSE clinical staff and HSE management.

METHODS

Qualitative design using the UK Medical Research Council's process evaluation framework. Purposive sampling techniques were used. A total of N = 40 key informant semi-structured interviews were completed which included clinical staff (N = 22), health service managers and administrators (N = 9), service users (N = 8) and a family member (N = 1). Thematic analyses were conducted.

RESULTS

Unique features of the EIP service (e.g., speed of referral/assessment, multidisciplinary approach, a range of evidence-based interventions and assertive MDT follow up) and enthusiasm for EIP were identified as two key factors that facilitated implementation. In contrast, obstacles to staff recruitment and budget challenges emerged as two primary barriers to implementation.

CONCLUSIONS

The findings from this research provide real world insights into the complexity of implementing an innovative service within an existing health system. Clear and committed financial and human resource processes which allow new innovations to thrive and be protected during their initiation and early implementation phase are paramount. These elements should be considered in the planning and implementation of EIP services both nationally in Ireland and internationally.

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.

Perceived Mistreatment in Health Care Settings and its Relationship with HIV Clinical Outcomes in HIV-positive People who Use Drugs in Vancouver, Canada

People living with HIV (PLWH) often experience stigma and discrimination by health care professionals. We investigated the prevalence of perceived mistreatment in health care settings and its associations with HIV clinical outcomes and health care-seeking behaviour using data from a long-running prospective cohort of PLWH who use drugs. Of the 857 participants included, 19% reported at least one instance of perceived mistreatment during the study period. In adjusted longitudinal analyses, perceived mistreatment was positively associated with not being on ART in the same follow-up period, and participants who reported perceived mistreatment were less likely to report seeing a physician in the subsequent follow-up period. Daily use of injection drugs was positively associated with reporting perceived mistreatment. These findings demonstrate the implications of negative health care interactions in a population that must consistently engage with the health care system, and the need for stigma-reducing educational interventions for health care professionals.

Cannabis use to manage stimulant cravings among people who use unregulated drugs

BACKGROUND

We sought to analyze the association between cannabis use to manage stimulant cravings and self-reported changes in stimulant use among structurally marginalized people who use unregulated drugs (PWUD).

METHODS

The data for this secondary analysis was collected from a cross-sectional questionnaire administered to people who concurrently use cannabis and unregulated stimulants in Vancouver, Canada. We used logistic regression models to analyze the association between cannabis use to manage stimulant cravings and self-reported changes in the frequency of stimulant use.

RESULTS

In total, 297 individuals were included in the present study. Cannabis use to manage stimulant cravings was reported by 134 (45.1 %) participants and 104 (77.6 %) of these participants reported decreasing their stimulant use during periods of cannabis use. In the multivariable logistic regression analysis, cannabis use to manage stimulant cravings (adjusted Odds Ratio [aOR] = 0.24, 95 % confidence interval [CI]: 0.10, 0.56) was significantly associated with self-reported reductions in stimulant use. In the sub-analyses, cannabis use to manage stimulant cravings was significantly associated with reduced stimulant use among people who used crystal methamphetamine daily (aOR = 0.08, 95 % CI: 0.02-0.37) and was not significantly associated with reduced stimulant use among people who used crack/cocaine daily (aOR = 0.33, 95 % CI: 0.04-2.86).

CONCLUSIONS

These findings indicate that cannabis use to manage stimulant cravings is a common harm reduction strategy and suggest that this may be an effective strategy to reduce stimulant use among some PWUD.

Prevalence and Correlates of Heavy Alcohol use among People Living with HIV who use Unregulated Drugs in Vancouver, Canada

Among people living with HIV (PLWH), heavy alcohol use is associated with many negative health consequences. However, the impacts of heavy alcohol use are not well described for PLWH who use drugs. Thus, we investigated the prevalence and correlates of heavy alcohol use among a cohort of people who use drugs (PWUD) living with HIV in Vancouver, Canada. We accessed data from an ongoing community-recruited prospective cohort of PLWH who use drugs with linked comprehensive HIV clinical monitoring data. We used generalized linear mixed-effects modeling to identify factors longitudinally associated with periods of heavy alcohol use between December 2005 and December 2019. Of the 896 participants included, 291 (32.5%) reported at least one period with heavy alcohol use. Periods of recent incarceration (Adjusted Odds Ratio [AOR] = 1.48, 95% Confidence Interval [CI]: 1.01-2.17), encounters with police (AOR = 1.87, 95% CI: 1.37-2.56), and older age (AOR = 1.05, 95% CI: 1.02-1.07) were positively associated with heavy alcohol use. Engagement in drug or alcohol treatment (AOR = 0.54, 95% CI: 0.42-0.70) and male gender (AOR = 0.46; 95% CI: 0.27-0.78) were negatively associated with heavy alcohol use. We observed that heavy alcohol use was clearly linked to involvement with the criminal justice system. These findings, together with the protective effects of substance use treatment, suggest the need to expand access for drug and alcohol treatment programs overall, and in particular through the criminal justice system to reduce alcohol-related harms among PLWH who use drugs.