title: Impact of treatment for opioid dependence on fatal drug-related poisoning: a national cohort study in England.
abstract: OBJECTIVE
  To compare the change in illicit opioid users' risk of fatal drug-related poisoning (DRP) associated with opioid agonist pharmacotherapy (OAP) and psychological support, and investigate the modifying effect of patient characteristics, criminal justice system (CJS) referral and treatment completion.
  
  
  METHODS
  National data linkage cohort study of the English National Drug Treatment Monitoring System and the Office for National Statistics national mortality database. Data were analysed using survival methods.
  
  
  METHODS
  All services in England that provide publicly funded, structured treatment for illicit opioid users.
  
  
  METHODS
  Adults treated for opioid dependence during April 2005 to March 2009: 151,983 individuals; 69% male; median age 32.6 with 442,950 person-years of observation.
  
  
  METHODS
  The outcome was fatal DRP occurring during periods in or out of treatment, with adjustment for age, gender, substances used, injecting status and CJS referral.
  
  
  RESULTS
  There were 1499 DRP deaths [3.4 per 1000 person-years, 95% confidence interval (CI) = 3.2-3.6]. DRP risk increased while patients were not enrolled in any treatment [adjusted hazard ratio (aHR) = 1.73, 95% CI = 1.55-1.92]. Risk when enrolled only in a psychological intervention was double that during OAP (aHR = 2.07, 95% CI = 1.75-2.46). The increased risk when out of treatment was greater for men (aHR = 1.88, 95% CI = 1.67-2.12), illicit drug injectors (aHR = 2.27, 95% CI = 1.97-2.62) and those reporting problematic alcohol use (aHR = 2.37, 95% CI = 1.90-2.98).
  
  
  CONCLUSIONS
  Patients who received only psychological support for opioid dependence in England appear to be at greater risk of fatal opioid poisoning than those who received opioid agonist pharmacotherapy.
authors.affiliation: Institute of Brain Behaviour and Mental Health, Faculty of Medical and Human Sciences, University of Manchester, UK.|Institute of Population Health, Faculty of Medical and Human Sciences, University of Manchester, UK.
authors.forename: Matthias
authors.initials: M
authors.lastname: Pierce
authors.affiliation: MRC Biostatistics Unit, Cambridge, UK.
authors.forename: Sheila M
authors.initials: SM
authors.lastname: Bird
authors.affiliation: School of Social and Community Medicine, University of Bristol, UK.
authors.forename: Matthew
authors.initials: M
authors.lastname: Hickman
authors.affiliation: Addictions Department, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK.
authors.forename: John
authors.initials: J
authors.lastname: Marsden
authors.affiliation: Institute of Population Health, Faculty of Medical and Human Sciences, University of Manchester, UK.
authors.forename: Graham
authors.initials: G
authors.lastname: Dunn
authors.affiliation: Institute of Population Health, Faculty of Medical and Human Sciences, University of Manchester, UK.
authors.forename: Andrew
authors.identifier: http://orcid.org/0000-0003-3545-4080
authors.initials: A
authors.lastname: Jones
authors.affiliation: Institute of Brain Behaviour and Mental Health, Faculty of Medical and Human Sciences, University of Manchester, UK.
authors.forename: Tim
authors.initials: T
authors.lastname: Millar
mesh_terms: D000293:Adolescent; D000328:Adult; D000701:Analgesics, Opioid / Q000506:poisoning*; D002047:Buprenorphine / Q000627:therapeutic use; D015331:Cohort Studies; D003131:Combined Modality Therapy; D062787:Drug Overdose / Q000401:mortality; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008691:Methadone / Q000627:therapeutic use; D008875:Middle Aged; D009294:Narcotics / Q000627:therapeutic use; D058850:Opiate Substitution Treatment / Q000401:mortality; D009293:Opioid-Related Disorders / Q000401:mortality / Q000534:rehabilitation*; D011613:Psychotherapy / Q000379:methods; D055815:Young Adult
chemical_list: D000701:Analgesics, Opioid; D009294:Narcotics; D002047:Buprenorphine; D008691:Methadone
keywords: Drug-related poisoning; opiate dependence; opioid agonist pharmacotherapy; overdose; psychosocial treatment; residential treatment