title: Predictors of non-adherence to methadone maintenance treatment in opioid-dependent individuals: implications for clinicians.
abstract: BACKGROUND
  Although methadone maintenance treatment (MMT) is recognized as the treatment of reference for opioid dependence, little information is available regarding the dynamic adherence to methadone and its determinants. With data from the Methaville trial we investigated the evolution of non-adherence to methadone and the effect of pre-treatment and in-treatment factors on longterm non-adherence to methadone.
  
  
  METHODS
  We selected 145 patients to study adherence to methadone at 3, 6 and 12 months (M3, M6 and M12, respectively) using a multidimensional questionnaire and a 3-level variable "adherent"/"non adherent"/"highly nonadherent". We then identified the pre-treatment and in-treatment variables associated with long-term non-adherence to methadone at the M12 visit using a univariate logistic regression and two different multivariate models: the first incorporating only the pre-treatment variables, the second adding the in-treatment variables to the pre-treatment ones.
  
  
  RESULTS
  At the M12 visit, 35.2% of the participants remained adherent, 55.9% and 9% were non-adherent and highly non-adherent, respectively. The multivariate analysis of long-term non-adherence to methadone showed 4 pre-treatment predictors and 1 in-treatment predictor as follows: being female, not having stable housing, alcohol consumption, cocaine use and perceiving methadone dose as inadequate.
  
  
  CONCLUSIONS
  Our findings highlight that pretreatment predictors are important to consider when starting maintenance treatment for opioid dependence, such as cocaine use and problematic alcohol consumption but also low socio-economic levels. In addition, during maintenance treatment, in-treatment predictors such as methadone dose adequacy is a crucial issue to achieve good adherence to MMT.
authors.forename: Perrine
authors.initials: P
authors.lastname: Roux
authors.forename: Caroline
authors.initials: C
authors.lastname: Lions
authors.forename: Laurent
authors.initials: L
authors.lastname: Michel
authors.forename: Julien
authors.initials: J
authors.lastname: Cohen
authors.forename: Marion
authors.initials: M
authors.lastname: Mora
authors.forename: Fabienne
authors.initials: F
authors.lastname: Marcellin
authors.forename: Bruno
authors.initials: B
authors.lastname: Spire
authors.forename: Alain
authors.initials: A
authors.lastname: Morel
authors.forename: Patrizia M
authors.initials: PM
authors.lastname: Carrieri
authors.forename: Laurent
authors.initials: L
authors.lastname: Karila
authors.affiliation: INSERM U912 - ORS PACA, 23 rue Stanislas Torrents, 13006 Marseille, France. perrine.roux@inserm.fr.
mesh_terms: D000328:Adult; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008691:Methadone / Q000008:administration & dosage / Q000627:therapeutic use*; D058850:Opiate Substitution Treatment; D009293:Opioid-Related Disorders / Q000188:drug therapy*; D016903:Drug Monitoring
chemical_list: D000701:Analgesics, Opioid; D008691:Methadone