title: Prescription opioid use and non-fatal overdose in a cohort of injection drug users.
abstract: BACKGROUND
  There is growing concern regarding rising rates of prescription drug-related deaths among the general North American population as well as increasing availability of illicitly obtained prescription opioids. Concurrently among people who inject drugs (IDU), illicit prescription opioid use has increased while non-fatal overdose remains a major source of morbidity.
  
  
  OBJECTIVE
  To evaluate whether the use of prescription opioids was associated with non-fatal overdose among IDU in Vancouver, Canada.
  
  
  METHODS
  Data was obtained from two open prospective cohorts of IDU between December 2005 and May 2013. We used generalized estimating equation (GEE) logistic regression to evaluate the association between prescription opioid use and non-fatal overdose, adjusting for various social, demographic, and behavioral factors.
  
  
  RESULTS
  There were 1614 IDU, including 541 (33.5%) women, who were recruited and included in this analysis. At baseline, 526 (32.6%) reported using prescription opioids and 118 (7.3%) reported experiencing an overdose in the previous six months. In a multivariable analysis, prescription opioid use remained independently associated with non-fatal overdose (adjusted odds ratio: 1.61, 95% confidence interval: 1.32-1.95), after adjusting for confounders.
  
  
  CONCLUSIONS
  We observed relatively high rates of prescription opioid use among IDU in this setting, and found an independent association between prescription opioid use and non-fatal overdose. Our data is likely representative of riskier substance use associated with those who use prescription opioids within our sample. Interventions to prevent and respond to overdoses should consider the higher risk profiles of IDU who use prescription opioids.
authors.affiliation: British Columbia Centre for Excellence in HIV/AIDS, St. Paul's Hospital , Vancouver , BC .
authors.forename: Stephanie
authors.initials: S
authors.lastname: Lake
authors.forename: Evan
authors.initials: E
authors.lastname: Wood
authors.forename: Jane
authors.initials: J
authors.lastname: Buxton
authors.forename: Huiru
authors.initials: H
authors.lastname: Dong
authors.forename: Julio
authors.initials: J
authors.lastname: Montaner
authors.forename: Thomas
authors.initials: T
authors.lastname: Kerr
mesh_terms: D000328:Adult; D000368:Aged; D002170:Canada / Q000453:epidemiology; D062787:Drug Overdose / Q000453:epidemiology*; D055030:Drug Users; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009293:Opioid-Related Disorders / Q000453:epidemiology*; D055553:Prescription Drugs; D015995:Prevalence; D015819:Substance Abuse, Intravenous / Q000453:epidemiology*
chemical_list: D055553:Prescription Drugs
keywords: Injection drug use; non-fatal overdose; opioid analgesics; prescription opioids