Prevalence and correlates of stocking up on drugs during the COVID-19 pandemic: Data from the C3PNO Consortium

BACKGROUND

Data from the COVID-19 pandemic describes increases in drug use and related harms, especially fatal overdose. However, evidence is needed to better understand the pathways from pandemic-related factors to substance use behaviours. Thus, we investigated stockpiling drugs among people who use drugs (PWUD) in five cities in the United States and Canada.

METHODS

We used data from two waves of interviews among participants in nine prospective cohorts to estimate the prevalence and correlates of stockpiling drugs in the previous month. Longitudinal correlates were identified using bivariate and multivariate generalized linear mixed-effects modeling analyses.

RESULTS

From May 2020 to February 2021, we recruited 1873 individuals who completed 2242 interviews, of whom 217 (11.6%) reported stockpiling drugs in the last month at baseline. In the multivariate model, stockpiling drugs was significantly and positively associated with reporting being greatly impacted by COVID-19 (Adjusted Odds Ratio [AOR]= 1.21, 95% CI: 1.09-1.45), and at least daily use of methamphetamine (AOR = 4.67, 95% CI: 2.75-7.94) in the past month.

CONCLUSIONS

We observed that approximately one-in-ten participants reported stocking up on drugs during the COVID-19 pandemic. This behaviour was associated with important drug-related risk factors including high-intensity methamphetamine use. While these correlations need further inquiry, it is possible that addressing the impact of COVID-19 on vulnerable PWUD could help limit drug stockpiling, which may lower rates of high-intensity stimulant use.

Changes in drug use behaviors coinciding with the emergence of illicit fentanyl among people who use drugs in Vancouver, Canada

Background: With the emergence of illicitly-manufactured fentanyl, drug overdose deaths have risen in unprecedented numbers. In this context, there is an urgent need to characterize potential changes in drug use behaviors among people who use drugs (PWUD). Objective: To examine changes in drug use behaviors following the emergence of illicit fentanyl among people who use drugs (PWUD). Methods: Data for this cross-sectional analysis was derived from three prospective cohorts of PWUD between December 2016 and May 2017 in Vancouver, Canada. Multivariable logistic regression was used to determine factors associated with self-reported behavior changes (binary variable "yes" or "no") following the emergence of illicit fentanyl. Results: Among 999 participants [363 (36.3%) females], 388 (38.8%) reported some behavior change. The remaining 611 (61.2%) reported no change in behavior; 240 (39.3%) of these individuals had recently been exposed to fentanyl. In multivariable analyses, factors independently associated with behavior change included recent non-fatal overdose (Adjusted Odds Ratio [AOR] = 2.28), active injection drug use (AOR = 1.96), being on opioid agonist therapy (AOR = 1.80), and urine drug screen positive for fentanyl (AOR = 1.45), (all p < .05). Conclusion: The majority of PWUD in our sample did not change their drug use behavior despite a high prevalence of fentanyl exposure, indicating a need for targeted behavior change messaging and overdose prevention efforts such as naloxone and addiction treatment for this sub-population of PWUD. Further, the high fentanyl exposure observed in our sample suggests a need to address upstream structural factors shaping the overdose risk in addition to individual behavioral change.

Do law enforcement interactions reduce the initiation of injection drug use? An investigation in three North American settings

BACKGROUND

The prevention of drug injecting is often cited as a justification for the deployment of law enforcement and for the continuation of drug criminalization policies. We sought to characterize the impact of law enforcement interactions on the risk that people who inject drugs (PWID) report assisting others with injection initiation in three North American countries.

METHODS

Cross-sectional data from PWID participating in cohort studies in three cities (San Diego, USA; Tijuana, Mexico; Vancouver, Canada) were pooled (August 2014-December 2016). The dependent variable was defined as recently (i.e., past six months) providing injection initiation assistance; the primary independent variable was the frequency of recent law enforcement interactions, defined categorically (0 vs. 1 vs. 2-5 vs. ≥6). We employed multivariable logistic regression analyses to assess this relationship while controlling for potential confounders.

RESULTS

Among 2122 participants, 87 (4.1%) reported recently providing injection initiation assistance, and 802 (37.8%) reported recent law enforcement interactions. Reporting either one or more than five recent interactions with law enforcement was not significantly associated with injection initiation assistance. Reporting 2-5 law enforcement interactions was associated with initiation assistance (Adjusted Odds Ratio=1.74, 95% Confidence Interval: 1.01-3.02).

CONCLUSIONS

Reporting interactions with law enforcement was not associated with a reduced likelihood that PWID reported initiating others into injection drug use. Instead, we identified a positive association between reporting law enforcement interactions and injection initiation assistance among PWID in multiple settings. These findings raise concerns regarding the effectiveness of drug law enforcement to deter injection drug use initiation.

Aboriginal street-involved youth experience elevated risk of incarceration

OBJECTIVES

Past research has identified risk factors associated with incarceration among adult Aboriginal populations; however, less is known about incarceration among street-involved Aboriginal youth. Therefore, we undertook this study to longitudinally investigate recent reports of incarceration among a prospective cohort of street-involved youth in Vancouver, Canada.

STUDY DESIGN

Prospective cohort study.

METHODS

Data were collected from a cohort of street-involved, drug-using youth from September 2005 to May 2013. Multivariate generalized estimating equation analyses were employed to examine the potential relationship between Aboriginal ancestry and recent incarceration.

RESULTS

Among our sample of 1050 youth, 248 (24%) reported being of aboriginal ancestry, and 378 (36%) reported being incarcerated in the previous six months at some point during the study period. In multivariate analysis controlling for a range of potential confounders including drug use patterns and other risk factors, Aboriginal ancestry remained significantly associated with recent incarceration (adjusted odds ratio [AOR] = 1.44; 95% confidence interval [CI]: 1.12-1.86).

CONCLUSIONS

Even after adjusting for drug use patterns and other risk factors associated with incarceration, this study found that Aboriginal street-involved youth were still significantly more likely to be incarcerated than their non-Aboriginal peers. Given the established harms associated with incarceration these findings underscore the pressing need for systematic reform including culturally appropriate interventions to prevent Aboriginal youth from becoming involved with the criminal justice system.

Phylogenetic clustering of hepatitis C virus among people who inject drugs in Vancouver, Canada

Little is known about factors associated with hepatitis C virus (HCV) transmission among people who inject drugs (PWID). Phylogenetic clustering and associated factors were evaluated among PWID in Vancouver, Canada. Data were derived from the Vancouver Injection Drug Users Study. Participants who were HCV antibody-positive at enrolment and those with HCV antibody seroconversion during follow-up (1996 to 2012) were tested for HCV RNA and sequenced (Core-E2 region). Phylogenetic trees were inferred using maximum likelihood analysis and clusters were identified using ClusterPicker (90% bootstrap threshold, 0.05 genetic distance threshold). Factors associated with clustering were assessed using logistic regression. Among 655 eligible participants, HCV genotype prevalence was: G1a: 48% (n=313), G1b: 6% (n=41), G2a: 3% (n=20), G2b: 7% (n=46), G3a: 33% (n=213), G4a: <1% (n=4), G6a: 1% (n=8), G6e: <1% (n=1), and unclassifiable: 1% (n=9). The mean age was 36 years, 162 (25%) were female, and 164 (25%) were HIV+. Among 501 participants with HCV G1a and G3a, 31% (n=156) were in a pair/cluster. Factors independently associated with phylogenetic clustering included: age <40 (versus age≥40, adjusted odds ratio [AOR]=1.64; 95% confidence interval [CI] 1.03, 2.63), human immunodeficiency virus (HIV) infection (AOR=1.82; 95% CI 1.18, 2.81), HCV seroconversion (AOR=3.05; 95% CI 1.40, 6.66), and recent syringe borrowing (AOR 1.59; 95% CI 1.07, 2.36).

CONCLUSION

In this sample of PWID, one-third demonstrated phylogenetic clustering. Factors independently associated with phylogenetic clustering included younger age, recent HCV seroconversion, prevalent HIV infection, and recent syringe borrowing. Strategies to enhance the delivery of prevention and/or treatment strategies to those with HIV and recent HCV seroconversion should be explored, given an increased likelihood of HCV transmission in these subpopulations.

Public injecting among a cohort of injecting drug users in Vancouver, Canada

BACKGROUND

Despite the implementation of policy interventions to address open drug consumption, public injecting continues to occur in many urban settings. This study sought to examine public injecting among a community-recruited cohort of injecting drug users (IDUs) in Vancouver.

METHODS

The prevalence and correlates of recent public injecting among participants enrolled in the Vancouver Injection Drug User Study during the period of 1 December 2003 to 30 November 2005 were examined prospectively using generalised estimating equations (GEEs).

RESULTS

Among the sample of 620 active IDUs, at some point during the study period, 142 (22.9%) individuals reported "usually" or "always" injecting in public in the 6 months prior to their study visit. Factors that were significant and positively associated with recent frequent public injecting in multivariate GEE analysis include homelessness (adjusted OR (AOR) 6.70); frequent crack use (AOR 1.48); and frequent heroin injection (AOR 1.56). Recent frequent public injecting was found to be negatively associated with cooking and filtering drugs prior to injecting (AOR 0.50) and older age (AOR 0.95).

CONCLUSION

The findings indicate that a substantial proportion of local IDUs frequently inject in public, and those who report recently injecting in public spaces appear to be a vulnerable population facing significant health hazards. The provision of secure housing may have the potential to protect the health of IDUs in this setting and significantly decrease the prevalence of public injecting. In addition, the findings support previous work suggesting that removing barriers to the use of Vancouver's existing supervised injection site may serve to further reduce public drug use.