Open AccessFrequent Cannabis Use Is Negatively Associated with Frequency of Injection Drug Use Among People Who Inject Drugs in a Canadian Setting
Author(s) -
Hudson Reddon,
Kora DeBeck,
M. Eugenia Socías,
Stephanie Lake,
Huiru Dong,
Kanna Hayashi,
M.J. Milloy
Publication year - 2020
Publication title -
cannabis and cannabinoid research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.156
H-Index - 17
eISSN - 2578-5125
pISSN - 2378-8763
DOI - 10.1089/can.2019.0104
Subject(s) - cannabis , medicine , confidence interval , odds ratio , drug , injection drug use , prospective cohort study , drug injection , environmental health , demography , psychiatry , sociology
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.