title: The impact of opioid substitution therapy on mortality post-release from prison: retrospective data linkage study.
abstract: OBJECTIVE
  Release from prison is a high-risk period for mortality. We examined the impact of opioid substitution therapy (OST), for opioid dependence during and after incarceration, upon mortality post-release.
  
  
  METHODS
  A cohort was formed of all opioid-dependent people who entered OST between 1985 and 2010 and who, following first OST entry, were released from prison at least once between 2000 and 2012. We linked data on OST history, court and prison records and deaths.
  
  
  METHODS
  New South Wales (NSW), Australia.
  
  
  METHODS
  A total of 16,453 people released from prison 60,161 times.
  
  
  METHODS
  Crude mortality rates (CMRs) were calculated according to OST retention; multivariable Cox regressions for post-release periods were undertaken to examine the association between OST exposure (a time-dependent variable) and mortality post-release, for which covariates were updated per-release.
  
  
  RESULTS
  There were 100,978 person-years (PY) post-release; 1050 deaths occurred. Most received OST while incarcerated (76.5%); individuals were receiving OST in 51% of releases. Lowest post-release mortality was among those continuously retained in OST post-release CMR 4 weeks post-release = 6.4 per 1000 PY; 95% confidence interval (CI) = 5.2, 7.8, highest among those with no OST (CMR = 36.7 per 1000 PY; 95% CI = 28.8, 45.9). Multi-factorial models showed OST exposure in the 4 weeks post-release reduced hazard of death by 75% (adjusted hazard ratio 0.25; 95% CI = 0.12, 0.53); OST receipt in prison had a short-term protective effect that decayed quickly across time.
  
  
  CONCLUSIONS
  In New South Wales, Australia, opioid substitution therapy in prison and post-release appears to reduce mortality risk in the immediate post-release period.
authors.affiliation: National Drug and Alcohol Research Centre, University of New South Wales, Sydney, NSW, Australia; School of Population and Global Health, University of Melbourne, Melbourne, Vic., Australia; Murdoch Children's Research Institute, Melbourne, Vic., Australia; Department of Global Health, School of Public Health, University of Washington, Seattle, WA, USA.
authors.forename: Louisa
authors.initials: L
authors.lastname: Degenhardt
authors.forename: Sarah
authors.initials: S
authors.lastname: Larney
authors.forename: Jo
authors.initials: J
authors.lastname: Kimber
authors.forename: Natasa
authors.initials: N
authors.lastname: Gisev
authors.forename: Michael
authors.initials: M
authors.lastname: Farrell
authors.forename: Timothy
authors.initials: T
authors.lastname: Dobbins
authors.forename: Don J
authors.initials: DJ
authors.lastname: Weatherburn
authors.forename: Amy
authors.initials: A
authors.lastname: Gibson
authors.forename: Richard
authors.initials: R
authors.lastname: Mattick
authors.forename: Tony
authors.initials: T
authors.lastname: Butler
authors.forename: Lucy
authors.initials: L
authors.lastname: Burns
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D003625:Data Collection / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009517:New South Wales / Q000453:epidemiology; D058850:Opiate Substitution Treatment / Q000706:statistics & numerical data*; D009293:Opioid-Related Disorders / Q000188:drug therapy* / Q000401:mortality*; D011329:Prisoners / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D055815:Young Adult
keywords: Crime; data linkage; mortality; opioid dependence; opioid substitution therapy; prison; treatment