Risk factors associated with benzodiazepine use among people who inject drugs in an urban Canadian setting

Background: Though known to have abuse potential, benzodiazepine medications remain widely prescribed. Furthermore, issues related to benzodiazepine use by people who inject drugs (PWID) remain to be fully characterized. We therefore sought to examine the prevalence of and risk factors associated with benzodiazepine use in a street-involved urban population.

Methods: Between May 1996 and November 2013, data were derived from two open prospective cohort studies in Vancouver, Canada, restricted to PWID. Multivariable logistic regression with generalized estimating equations (GEE) was used to determine factors independently associated with benzodiazepine use.

Results: Over the study period, 2806 individuals were recruited, including 949 (34%) women. Of these, 1080 (38.5%) participants reported benzodiazepine use at least once during the study period. In the multivariable analysis, Caucasian ethnicity, ≥ daily heroin injection, ≥ daily cocaine injection, non-fatal overdose, incarceration, syringe sharing, and unsafe sex were all independently associated with benzodiazepine use. Conversely, older age, homelessness, and ≥ daily crack smoking were negatively associated with benzodiazepine use.

Conclusions: Use of benzodiazepines was common in this urban setting and was associated with several markers of addiction severity and significant health and social vulnerabilities including syringe sharing and unsafe sex. These findings underscore the need to promote treatment for benzodiazepine use, safer benzodiazepine prescribing, including greater recognition of the limited indications for evidence-based use of this medication class.