title: Characteristics of opioid-users whose death was related to opioid-toxicity: a population-based study in Ontario, Canada.
abstract: BACKGROUND
  The impact of the prescription opioid public health crisis has been illustrated by the dramatic increase in opioid-related deaths in North America. We aimed to identify patterns and characteristics amongst opioid-users whose cause of death was related to opioid toxicity.
  
  
  METHODS
  This was a population-based study of Ontarians between the years 2006 and 2008. All drug-related deaths which occurred during this time frame were reviewed at the Office of the Chief Coroner of Ontario, and opioid-related deaths were identified. Medical, toxicology, pathology, and police reports were comprehensively reviewed. Narratives, semi-quantitative, and quantitative variables were extracted, tabulated, and analyzed.
  
  
  RESULTS
  Out of 2330 drug-related deaths in Ontario, 58% were attributed either in whole or in part, to opioids (n = 1359). Oxycodone was involved in approximately one-third of all opioid-related deaths. At least 7% of the entire cohort used opioids that were prescribed for friends and/or family, 19% inappropriately self-administered opioids (injection, inhalation, chewed patch), 3% were recently released from jail, and 5% had been switched from one opioid to another near the time of death. Accidental deaths were significantly associated with personal history of substance abuse, enrollment in methadone maintenance programs, cirrhosis, hepatitis, and cocaine use. Suicides were significantly associated with mental illness, previous suicide attempts, chronic pain, and a history of cancer.
  
  
  CONCLUSIONS
  These results identify novel, susceptible groups of opioid-users whose cause of death was related to opioids in Ontario and provide the first evidence to assist in quantifying the contribution of opioid misuse and diversion amongst opioid-related mortality in Canada. Multifaceted prevention strategies need to be developed based on subpopulations of opioid users.
authors.affiliation: Division of Clinical Pharmacology and Toxicology, Department of Pediatrics, Hospital for Sick Children, Toronto, Ontario, Canada. parvaz.madadi@gmail.com
authors.forename: Parvaz
authors.initials: P
authors.lastname: Madadi
authors.forename: Doris
authors.initials: D
authors.lastname: Hildebrandt
authors.forename: Albert E
authors.initials: AE
authors.lastname: Lauwers
authors.forename: Gideon
authors.initials: G
authors.lastname: Koren
mesh_terms: D000328:Adult; D000701:Analgesics, Opioid / Q000633:toxicity*; D002423:Cause of Death; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009864:Ontario / Q000453:epidemiology; D009293:Opioid-Related Disorders / Q000401:mortality* / Q000473:pathology
chemical_list: D000701:Analgesics, Opioid