title: Time to relapse following treatment for methamphetamine use: a long-term perspective on patterns and predictors.
abstract: BACKGROUND
  This paper describes methamphetamine (MA) use patterns, specifically the duration of continuing abstinence ("time to relapse") for periods averaging 5 years post-discharge from treatment for MA use, and the relationship with selected user and treatment characteristics.
  
  
  METHODS
  A sample of 350 treatment admissions from a large county substance use disorder (SUD) treatment system was randomly selected (within gender, race/ethnicity, treatment modality strata). Retrospective self-report data are from natural history interviews (NHI) conducted approximately 3 years after treatment and a follow-up of 2-3 years later. Relapse is defined as any use of MA with time as the number of months of continuous MA abstinence after treatment discharge until relapse. This outcome was constructed from a monthly MA use timeline using NHI data. A Cox model was used to examine time to relapse and predictors.
  
  
  RESULTS
  Sixty-one percent of the sample relapsed to MA use within 1 year after treatment discharge and 14% during years 2-5. Significant protective factors predicting longer time to relapse included having experienced serious MA-related psychiatric/behavioral problems (hazard ratio [HR]=0.75, p=0.027), longer duration of the index treatment episode (HR=0.93, p=0.001), and participating in self-help or other treatment during the post-treatment abstinence period (HR=0.29, p<0.001); risk factors for shorter time to relapse included having a parent with alcohol and/or drug use problems (HR=1.35, p=0.020) and involvement in MA sales (HR=1.48, p=0.002).
  
  
  CONCLUSIONS
  Results contribute a long-term perspective on patterns of MA use following treatment and support a need for early post-treatment and long-term continuing care and relapse-prevention services.
authors.affiliation: Integrated Substance Abuse Programs, Department of Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, 11075 Santa Monica Blvd., Suite 100, Los Angeles, CA 90025, United States; School of Nursing, University of California, Los Angeles, Factor 5-151, 700 Tiverton Ave., Los Angeles, CA 90095, United States. Electronic address: lbrecht@ucla.edu.
authors.forename: Mary-Lynn
authors.initials: ML
authors.lastname: Brecht
authors.affiliation: Integrated Substance Abuse Programs, Department of Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, 11075 Santa Monica Blvd., Suite 100, Los Angeles, CA 90025, United States.
authors.forename: Diane
authors.initials: D
authors.lastname: Herbeck
mesh_terms: D000328:Adult; D019969:Amphetamine-Related Disorders / Q000453:epidemiology* / Q000628:therapy; D016241:Child of Impaired Parents / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D015141:Los Angeles / Q000453:epidemiology; D008297:Male; D008694:Methamphetamine; D016016:Proportional Hazards Models; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors
chemical_list: D008694:Methamphetamine
keywords: Continuing abstinence; Cox regression; Long-term follow-up; Methamphetamine; Natural history interview; Relapse