title: Predictors of treatment retention in a major methadone maintenance treatment program in iran: a survival analysis.
abstract: BACKGROUND
  To identify correlates related to retention time of a cohort study of the opioid-dependent patients participating in the Methadone Maintenance Treatment (MMT) program offered by a major addiction treatment clinic in Tehran, Iran between April 2007 and March 2011.
  
  
  METHODS
  Several parametric Survival models assuming Weibull, Log-normal and Log-logistic distributions were compared to search for association between covariates and risk of relapse and dropping out of treatment among 198 patient participants.
  
  
  RESULTS
  According to Akaike Information Criterion (AIC), Log-normal model had the best fitting. Estimates of this model indicated that increase in average methadone dosage was associated with longer retention time. Correlates associated with shorter retention time were suffering from mental disorders, using stimulant drugs, being poly-substance dependents and having prior treatments.
  
  
  CONCLUSIONS
  Findings of this study provide support for giving more attention to patients who are poly-substance or stimulant-drug dependents, have non-substance psychiatric comorbidity and the ones with addiction treatment history. Independent of patient characteristics, retention improved as the dose of methadone increased.
authors.affiliation: Department of Public Health, School of Health, Kurdistan University of Medical Sciences, Sanandaj, Iran.Addiction Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Tahereh
authors.initials: T
authors.lastname: Pashaei
authors.affiliation: Health Management and Economics Research Center, Isfahan University of Medical Sciences, Isfahan, Iran.Iranian Center of Excellence in Health Services Management, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Moeeni
authors.affiliation: Addiction Research Center, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Babak
authors.initials: B
authors.lastname: Roshanaei Moghdam
authors.affiliation: Assistant professor, Faculty of Management and Economics, TarbiatModares University, Tehran, Iran.
authors.forename: Hassan
authors.initials: H
authors.lastname: Heydari
authors.affiliation: Centre for Addiction and Mental Health, Toronto, Canada.
authors.forename: Nigel E
authors.initials: NE
authors.lastname: Turner
authors.affiliation: Department of Psychiatry, Tehran University of Medical Sciences, Tehran, Iran. razaghie@sina.tums.ac.ir.
authors.forename: Emran M
authors.initials: EM
authors.lastname: Razaghi
mesh_terms: D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007492:Iran; D008297:Male; D008691:Methadone / Q000008:administration & dosage*; D058850:Opiate Substitution Treatment / Q000379:methods*; D009293:Opioid-Related Disorders / Q000188:drug therapy*; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data*; D012044:Regression Analysis; D012189:Retrospective Studies; D016019:Survival Analysis; D055815:Young Adult
chemical_list: D000701:Analgesics, Opioid; D008691:Methadone
keywords: Log-normal distribution; Methadone Maintenance Treatment; Opioid addiction; Relapse; Retention; Survival models