title: A longitudinal comparison of retention in buprenorphine and methadone treatment for opioid dependence in New South Wales, Australia.
abstract: OBJECTIVE
  To examine characteristics of first-time methadone and buprenorphine clients and factors associated with risk of leaving first treatment in New South Wales (NSW), Australia.
  
  
  METHODS
  Retrospective linkage study of opioid substitution therapy (OST) treatment, court, custody and mortality data.
  
  
  METHODS
  NSW, Australia.
  
  
  METHODS
  First-time OST entrants (August 2001-December 2010).
  
  
  METHODS
  Characteristics of clients were examined. Time-dependent Cox models examined factors associated with the risk of leaving first treatment, with demographic, criminographic and treatment variables jointly considered. Interactions between medication and other variables upon risk of leaving treatment were examined.
  
  
  RESULTS
  There were 15 600 treatment entrants: 7183 (46%) commenced buprenorphine, 8417 (54%) commenced methadone; the proportion entering buprenorphine increased over time. Those starting buprenorphine switched medications more frequently and had more subsequent treatment episodes. Buprenorphine retention was also poorer. On average, 44% spent 3+ months in treatment compared with 70% of those commencing methadone; however, buprenorphine retention for first-time entrants improved over time, whereas methadone retention did not. Multivariable Cox models indicated that in addition to sex, age, treatment setting and criminographic variables, the risk of leaving a first treatment episode was greater on any given day for those receiving buprenorphine, and was dependent on the year treatment was initiated. There was no interaction between any demographic variables and medication received, suggesting no clear evidence of any particular groups for whom each medication might be better suited in terms of improving retention.
  
  
  CONCLUSIONS
  Although retention rates for buprenorphine treatment have improved in New South Wales, Australia, individuals starting methadone treatment still show higher retention rates.
authors.affiliation: National Drug and Alcohol Research Centre, University of NSW, Sydney, Australia.
authors.forename: Lucy
authors.initials: L
authors.lastname: Burns
authors.forename: Natasa
authors.initials: N
authors.lastname: Gisev
authors.forename: Sarah
authors.initials: S
authors.lastname: Larney
authors.forename: Timothy
authors.initials: T
authors.lastname: Dobbins
authors.forename: Amy
authors.initials: A
authors.lastname: Gibson
authors.forename: Jo
authors.initials: J
authors.lastname: Kimber
authors.forename: Briony
authors.initials: B
authors.lastname: Larance
authors.forename: Richard P
authors.initials: RP
authors.lastname: Mattick
authors.forename: Tony
authors.initials: T
authors.lastname: Butler
authors.forename: Louisa
authors.initials: L
authors.lastname: Degenhardt
mesh_terms: D000328:Adult; D000701:Analgesics, Opioid / Q000627:therapeutic use*; D002047:Buprenorphine / Q000627:therapeutic use*; D003415:Crime / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008691:Methadone / Q000627:therapeutic use*; D008875:Middle Aged; D015999:Multivariate Analysis; D009517:New South Wales; D058850:Opiate Substitution Treatment; D009293:Opioid-Related Disorders / Q000188:drug therapy*; D010352:Patient Dropouts / Q000706:statistics & numerical data*; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D055815:Young Adult; D016903:Drug Monitoring
chemical_list: D000701:Analgesics, Opioid; D002047:Buprenorphine; D008691:Methadone
keywords: Buprenorphine; methadone; opioid dependence; opioid substitution treatment; treatment retention