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The Vancouver Intravenous Drug Users Study (VIDUS) is a long-running study of HIV-negative people who inject drugs, aiming to understand the natural history of injection drug use and inform the development of health policies and interfections.


V-DUS incorporates two long standing cohorts:

  • The Vancouver Injection Drug Users Study (VIDUS) = HIV negative adults who use injection drugs
  • At-Risk Youth Study (ARYS) = Street involved youth ages 14-26 who use drugs

These cohorts were combined in 2014 and permit longitudinal analyses of the natural history of drug use.


  • To examine the impact of prescription opioid misuse on injecting initiation and cessation, risk behaviors for HIV and other viruses, and non-fatal and fatal overdose in a setting with an active heroin market
  • To characterize early injecting careers, with a focus on the individual and social-structural factors that shape initiation, risk behaviors for HIV and other viruses, early cessation, and sustained injecting
  • To characterize established injecting careers, with a focus on the individual and social-structural and environmental factors that shape cessation of and relapse into injecting, morbidity and mortality
  • To continue to collect data that facilitate comparisons between HIV-positive and HIV-negative PWID in analyses that examine health service use, morbidity, and mortality.

Current Research

Fentanyl, Non-medical PO use, and Overdose

  • High levels of exposure to fentanyl (Hayashi et al., DAD 2018)
  • Non-medical PO use associated with injection initiation (DeBeck et al., IJDP 2016)
  • Initiation into PO use not associated with reduced heroin use (Lake et al., DAD 2016)
  • PO and heroin injection associated with significant increase in overdose risk (Lake et al., DAD 2015); HIV status not associated with overdose risk (Escudero at al., Addict Behav 2016)

Substance use treatment

  • Documented that MMT is protective against HCV infection (Nolan et al., Addiction 2014) and associated with better engagement in HCV care among HCV-positive PWID (Ti et al., PLOS ONE 2018)
  • Demonstrated that difficulty accessing addiction treatment independently predicts subsequent initiation into injection among young substance users (DeBeck et al., SATPP 2016)

Natural History of drug use

  • Characterizing injection initiation (Hadland et al., JAH 2012; Feng et al., JAH 2013)
  • Characterizing injection cessation (Ti et al., DAD 2014; Hadland et al., JAH 2017)
  • Documented declining mortality among HIV positive substance users during Seek, Test, Treat, Retain initiatives (Hayashi et al., JID 2017)

More Information