title: Methadone treatments in a Swiss region, 2001-2008: a registry-based analysis.
abstract: BACKGROUND
  To determine, in a region of Switzerland, the duration of retention in opioid substitution treatments with methadone (OSTM), duration of treatment interruptions, probability of re-entry to treatment after a treatment interruption, and associated factors.
  
  
  METHODS
  A secondary analysis of registry-based data was performed with patients (n = 2880) registered in the methadone treatment register database of the Public Health Service of the canton of Vaud between January 1, 2001 and June 30, 2008. Survival analysis and multivariate analysis was conducted.
  
  
  RESULTS
  The probability of remaining on treatment was 69% at 1 year and 45% at 3 years (n =1666). One-third of patients remained on treatment beyond 5 years. The estimated hazard of leaving treatment was increased by a ratio of 1.31 in the case of a first treatment (P = 0.001), 1.83 for those without a fixed home (P < 0.001), and 1.29 for those younger than 30 years old (P < 0.001). The probability of having begun a new treatment after a first interruption was 21% at one year, 38% at 3 years, and 43% at 5 years (n = 1581). Factors at the interruption of treatment associated with a higher probability of re-entering were: interruption not due to methadone withdrawal, bad physical health, and higher methadone dose.
  
  
  CONCLUSIONS
  OSTM are long-term (maintenance) treatments in Switzerland. Younger age, bad living conditions at entry, and first treatment are predictors of lower retention. Approximately one-half of patients who interrupt treatment will re-enter treatment within 5 years.
authors.affiliation: Institute of Social and Preventive Medicine, University Hospital Centre and University of Lausanne, Biopole 2 Route de la Corniche 10, CH - 1010, Lausanne, Switzerland.
authors.forename: Thérèse
authors.initials: T
authors.lastname: Huissoud
authors.forename: Valentin
authors.initials: V
authors.lastname: Rousson
authors.forename: Françoise
authors.initials: F
authors.lastname: Dubois-Arber
mesh_terms: D000328:Adult; D006801:Humans; D008691:Methadone / Q000627:therapeutic use*; D058850:Opiate Substitution Treatment / Q000379:methods* / Q000639:trends; D012042:Registries; D013557:Switzerland; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D008691:Methadone