Objectives To examine the relationship between non-fatal overdose and risk of subsequent fatal overdose. Methods We assessed risk factors for overdose death among two prospective cohorts of persons who inject drugs (PWID) in Vancouver, Canada. Extended Cox regression was used to examine if reports of non-fatal overdose were associated with the time to fatal overdose while adjusting for other behavioral, social and structural confounders. Results Between May, 1996 and December, 2011, 2,317 individuals were followed for a median of 60.8 months. In total, 134 fatal overdose deaths were identified for an incidence density of 8.94 (95% confidence interval [CI]: 7.55 – 10.59) deaths per 1,000 person-years. During the study period there were 1795 reports of non-fatal overdose. In a multivariate model, recent non-fatal overdose was independently associated with the time to overdose mortality (adjusted hazard ratio [AHR] = 1.95; 95% CI: 1.17 - 3.27). As well, there was a dose response effect of increasing cumulative reports of non-fatal overdose on subsequent fatal overdose. Conclusion Reports of recent non-fatal overdose were independently associated with subsequent overdose mortality in a dose-response relationship. These findings suggest that individuals reporting recent non-fatal overdose should be engaged with intensive overdose prevention interventions.

Stimulant use disorder contributes to a substantial worldwide burden of disease, although evidence-based treatment options are limited. This systematic review of reviews aims to: (i) synthesize the available evidence on both psychosocial and pharmacological interventions for the treatment of stimulant use disorder; (ii) identify the most effective therapies to guide clinical practice, and (iii) highlight gaps for future study. Methods A systematic database search was conducted to identify systematic reviews and meta-analyses. Eligible studies were those that followed standard systematic review methodology and assessed randomized controlled trials focused on the efficacy of interventions for stimulant use disorder. Articles were critically appraised using an assessment tool adapted from Palmeteer et al. and categorized for quality as 'core' or 'supplementary' reviews. Evidence from the included reviews were further synthesized according to pharmacological or non-pharmacological management themes. Results Of 476 identified records, 29 systematic reviews examining eleven intervention modalities were included. The interventions identified include: contingency management, cognitive behavioural therapy, acupuncture, antidepressants, dopamine agonists, antipsychotics, anticonvulsants, disulfiram, opioid agonists, N-Acetylcysteine, and psychostimulants. There was sufficient evidence to support the efficacy of contingency management programs for treatment of stimulant use disorder. Psychostimulants, n-acetylcysteine, opioid agonist therapy, disulfiram and antidepressant pharmacological interventions were found to have insufficient evidence to support or discount their use. Results of this review do not support the use of all other treatment options.

Summary Background People who inject drugs (PWID) are at increased risk for HIV and hepatitis C virus (HCV) infection and also have high levels of homelessness and unstable housing. We assessed whether homelessness or unstable housing is associated with an increased risk of HIV or HCV acquisition among PWID compared with PWID who are not homeless or are stably housed. Methods In this systematic review and meta-analysis, we updated an existing database of HIV and HCV incidence studies published between Jan 1, 2000, and June 13, 2017. Using the same strategy as for this existing database, we searched MEDLINE, Embase, and PsycINFO for studies, including conference abstracts, published between June 13, 2017, and Sept 14, 2020, that estimated HIV or HCV incidence, or both, among community-recruited PWID. We only included studies reporting original results without restrictions to study design or language. We contacted authors of studies that reported HIV or HCV incidence, or both, but did not report on an association with homelessness or unstable housing, to request crude data and, where possible, adjusted effect estimates. We extracted effect estimates and pooled data using random-effects meta-analyses to quantify the associations between recent (current or within the past year) homelessness or unstable housing compared with not recent homelessness or unstable housing, and risk of HIV or HCV acquisition. We assessed risk of bias using the Newcastle-Ottawa Scale and between-study heterogeneity using the I 2 statistic and p value for heterogeneity. Findings We identified 14 351 references in our database search, of which 392 were subjected to full-text review alongside 277 studies from our existing database. Of these studies, 55 studies met inclusion criteria. We contacted the authors of 227 studies that reported HIV or HCV incidence in PWID but did not report association with the exposure of interest and obtained 48 unpublished estimates from 21 studies. After removal of duplicate data, we included 37 studies with 70 estimates (26 for HIV; 44 for HCV). Studies originated from 16 countries including in North America, Europe, Australia, east Africa, and Asia. Pooling unadjusted estimates, recent homelessness or unstable housing was associated with an increased risk of acquiring HIV (crude relative risk [cRR] 1·55 [95% CI 1·23–1·95; p=0·0002]; I 2 = 62·7%; n=17) and HCV (1·65 [1·44–1·90; p<0·0001]; I 2 = 44·8%; n=28]) among PWID compared with those who were not homeless or were stably housed. Associations for both HIV and HCV persisted when pooling adjusted estimates (adjusted relative risk for HIV: 1·39 [95% CI 1·06–1·84; p=0·019]; I 2 = 65·5%; n=9; and for HCV: 1·64 [1·43–1·89; p<0·0001]; I 2 = 9·6%; n=14). For risk of HIV acquisition, the association for unstable housing (cRR 1·82 [1·13–2·95; p=0·014...

Women residing at domestic violence shelters (S group) were nearly 11 times more likely to report that their partner had hurt or killed pets than a comparison group of women who said they had not experienced intimate violence (NS group). Reports of threatened harm to pets were more than 4 times higher for the S group. Using the Conflict Tactics Scale, the authors demonstrated that severe physical violence was a significant predictor of pet abuse. The vast majority of shelter women described being emotionally close to their pets and distraught by the abuse family pets experienced. Children were often exposed to pet abuse, and most reported being distressed by these experiences. A substantial minority of S-group women reported that their concern for their pets' welfare prevented them from seeking shelter sooner. This seemed truer for women without children, who may have had stronger pet attachments. This obstacle to seeking safety should be addressed by domestic violence agencies.

Background & Aims: Despite the high burden of hepatitis C virus (HCV) infection among people who inject drugs (PWID), uptake of interferon-based therapies has been extremely low. Increasing availability of direct-acting antiviral (DAA)-based therapies offers the possibility of rapid treatment expansion with the goal of controlling the HCV epidemic. We evaluated DAA-based treatment uptake among HCVpositive PWID in Vancouver after introduction of DAAs in the government drug formulary. Methods: Using data from three cohorts of PWID in Vancouver, Canada, we investigated factors associated with DAA-therapies uptake among participants with HCV Results: Of the 915 HCV-positive PWID, 611 (66.8%) were recent PWID and 369 (40.3%) had HIV coinfection. During the study period, 146 (16.0%) initiated DAA-therapies, a rate of 6.0 per 100 person-year, with higher initiation rates among non-recent PWID and an increasing trend over time. In multivariable analysis, HIV coinfection (Adjusted Odds Ratio [AOR] = 2.29, 95% Confidence Interval [CI]: 1.55-3.40), white race (AOR = 1.56, 95% CI: 1.05-2.35), and engagement in HCV care (AOR = 1.94, 95%CI: 1.31-2.90) were positively associated with DAA-therapies uptake, while high-risk drinking (AOR = 0.47, 95% CI: 0.23-0.88) and daily crack use were negatively associated (AOR = 0.41, 95% CI: 0.17-0.85). Among recent PWID, engagement in opioid agonist therapy emerged as an independent correlate of DAA uptake. Conclusions:Despite increases in HCV treatment uptake among PWID after the introduction of DAAs in our setting, disparities in access remain. Social-structural and behavioural barriers to HCV care should be addressed for the success of any HCV elimination strategy.

BackgroundLeaving hospital against medical advice (AMA) is common among people who use illicit drugs (PWUD) and is associated with severe health-related harms and costs. However, little is known about the prevalence of and factors associated with leaving AMA among PWUD.MethodsData were collected through two Canadian prospective cohort studies involving PWUD between September 2005 and July 2011 and linked to a hospital admission/discharge database. Bivariable and multivariable generalized estimating equations were used to examine factors associated with leaving hospital AMA among PWUD who were hospitalized.ResultsAmong 488 participants who experienced at least one hospitalization, 212 (43.4%) left the hospital AMA at least once during the study period. In multivariable analyses, factors positively and significantly associated with leaving hospital AMA included: unstable employment (AOR = 1.92; 95% confidence interval [CI]: 1.22–3.03); recent incarceration (AOR = 1.63; 95%CI: 1.07–2.49); ≥ daily heroin injection (AOR = 1.49; 95%CI: 1.05–2.11); and younger age per year younger (adjusted odds ratio [AOR] = 1.04; 95%CI: 1.02–1.06).ConclusionsWe found a substantial proportion of PWUD in this setting left hospital AMA and that various markers of risk and vulnerability were associated with this phenomenon. Our findings highlight the need to address substance abuse issues early following hospital admission. These findings further suggest a need to develop novel interventions to minimize PWUD leaving hospital prematurely.

Background While persons with addiction are often hospitalized, hospitals typically employ abstinence-based policies specific to illicit drug use. Although illicit drug use is known to occur within hospitals, this problem has not been well characterized. Therefore, we sought to investigate the prevalence of and factors associated with having ever used drugs in hospital among people who use drugs (PWUD) in Vancouver, Canada. Methods Data were derived from prospective cohort studies of PWUD between December 2012 and May 2013. Multivariable logistic regression was used to identify demographic and behavioural factors associated with having ever used illicit drugs in hospital. Results Among 1028 participants who had experienced ≥ 1 hospitalization, 43.9% reported having ever used drugs while hospitalized. In multivariable analyses, factors positively associated with having ever used drugs in hospital included: daily cocaine injection and daily crack non-injection (both p < 0.05). Factors negatively associated with the outcome included: older age and male gender (both p < 0.05). The most common reasons for drug use in hospital were “wanting to use” and “being in withdrawal”. Drugs were most commonly used in patient washrooms. Conclusions Our findings demonstrate that an abstinence-based approach to drug use in hospitals may be ineffective at prohibiting drug consumption. High-risk drug use behaviours arising from ongoing drug use may pose risks for further harm and illness. Efforts to minimize the harms associated with using drugs in hospital are urgently needed.

In the present study, we sought to identify rates, causes, and predictors of death among male and female injection drug users (IDUs) in Vancouver, British Columbia, Canada, during a period of expanded public health interventions. Data from prospective cohorts of IDUs in Vancouver were linked to the provincial database of vital statistics to ascertain rates and causes of death between 1996 and 2011. Mortality rates were analyzed using Poisson regression and indirect standardization. Predictors of mortality were identified using multivariable Cox regression models stratified by sex. Among the 2,317 participants, 794 (34.3%) of whom were women, there were 483 deaths during follow-up, with a rate of 32.1 (95% confidence interval (CI): 29.3, 35.0) deaths per 1,000 person-years. Standardized mortality ratios were 7.28 (95% CI: 6.50, 8.14) for men and 15.56 (95% CI: 13.31, 18.07) for women. During the study period, mortality rates related to infection with human immunodeficiency virus (HIV) declined among men but remained stable among women. In multivariable analyses, HIV seropositivity was independently associated with mortality in both sexes (all P < 0.05). The excess mortality burden among IDUs in our cohorts was primarily attributable to HIV infection; compared with men, women remained at higher risk of HIV-related mortality, indicating a need for sex-specific interventions to reduce mortality among female IDUs in this setting.