Contribution Proportional Hazards Frailty Models for Recurrent Methadone Maintenance Treatment

The authors’ objective in this study was to identify determinants of time to discontinuation of methadone maintenance treatment (MMT) across multiple treatment episodes. Population-level data on drug dispensations for all patients receiving methadone for opioid maintenance throughout the tenure of the British Columbia, Canada, methadone program to date (1996–2007) were extracted from an administrative database. Proportional hazards frailty models were developed to assess factors associated with time to discontinuation from recurrent MMT episodes. A total of 17,005 patients experienced 32,656 treatment episodes over the 11-year follow-up period. Age, medical comorbidity, and physician patient load, as well as neighborhood-level socioeconomic status indicators, were significant predictors of time to discontinuation of treatment; treatment adherence and average daily doses up to and above 120 mg per day were also associated with longer treatment episodes. Studies have shown that while successfully retained in MMT, clients decrease their illicit drug use and criminal activity, and their risk of mortality is substantially lower; however, the majority of clients relapse. Many reenter treatment. The primary finding of this study was that patients experiencing multiple treatment episodes tended to stay in treatment for progressively longer periods in later episodes.

[1]  R. Hogg,et al.  Factors associated with geographic migration among a cohort of injection drug users. , 2008, Health & place.

[2]  T. Clausen,et al.  Mortality prior to, during and after opioid maintenance treatment (OMT): a national prospective cross-registry study. , 2008, Drug and alcohol dependence.

[3]  Y. Hser,et al.  The Life Course Perspective on Drug Use , 2007, Evaluation review.

[4]  Jonathan A C Sterne,et al.  The impact of residual and unmeasured confounding in epidemiologic studies: a simulation study. , 2007, American journal of epidemiology.

[5]  Richard J. Cook,et al.  The Statistical Analysis of Recurrent Events , 2007 .

[6]  Anthony Gamst,et al.  On proportional hazards assumption under the random effects models , 2007, Lifetime data analysis.

[7]  A. Somogyi,et al.  Switching between methadone and morphine for maintenance treatment of opioid dependence: impact on pain sensitivity and mood status. , 2006, The American journal on addictions.

[8]  S. Schreiber,et al.  Factors predicting retention in treatment: 10-year experience of a methadone maintenance treatment (MMT) clinic in Israel. , 2006, Drug and alcohol dependence.

[9]  J. Bell,et al.  Cycling in and out of treatment; participation in methadone treatment in NSW, 1990-2002. , 2006, Drug and alcohol dependence.

[10]  J. Hättenschwiler,et al.  Patterns of heroin, cocaine, and alcohol abuse during long-term methadone maintenance treatment. , 2005, Journal of substance abuse treatment.

[11]  W. van den Brink,et al.  Prediction of relapse to frequent heroin use and the role of methadone prescription: an analysis of the Amsterdam Cohort Study among drug users. , 2005, Drug and alcohol dependence.

[12]  Laura Amato,et al.  An overview of systematic reviews of the effectiveness of opiate maintenance therapies: available evidence to inform clinical practice and research. , 2005, Journal of substance abuse treatment.

[13]  C. Strike,et al.  Factors predicting 2-year retention in methadone maintenance treatment for opioid dependence. , 2005, Addictive behaviors.

[14]  D. Vlahov,et al.  Longitudinal patterns of drug injection behavior in the ALIVE Study cohort,1988-2000: description and determinants. , 2003, American journal of epidemiology.

[15]  F. Faggiano,et al.  Methadone maintenance at different dosages for opioid dependence. , 2003, The Cochrane database of systematic reviews.

[16]  G. Bovasso,et al.  The long-term outcomes of drug use by methadone maintenance patients , 2003, The Journal of Behavioral Health Services & Research.

[17]  Michael J. Goodman,et al.  Chronic Disease Score as a Predictor of Hospitalization , 2002, Epidemiology.

[18]  M Maclure,et al.  Performance of comorbidity scores to control for confounding in epidemiologic studies using claims data. , 2001, American journal of epidemiology.

[19]  F. Gutzwiller,et al.  Feasibility, safety, and efficacy of injectable heroin prescription for refractory opioid addicts: a follow-up study , 2001, The Lancet.

[20]  B. Jamerson,et al.  Bupropion SR as an aid to smoking cessation in smokers treated previously with bupropion: A randomized placebo‐controlled study , 2001, Clinical pharmacology and therapeutics.

[21]  A T McLellan,et al.  Drug dependence, a chronic medical illness: implications for treatment, insurance, and outcomes evaluation. , 2000, JAMA.

[22]  B. Fischer.  Prescriptions, Power and Politics: The Turbulent History of Methadone Maintenance in Canada , 2000, Journal of public health policy.

[23]  R. Craig,et al.  Methadone maintenance. Does dose determine differences in outcome? , 1999, Journal of substance abuse treatment.

[24]  Jeff Ward,et al.  Role of maintenance treatment in opioid dependence , 1999, The Lancet.

[25]  D J Sargent,et al.  A general framework for random effects survival analysis in the Cox proportional hazards setting. , 1998, Biometrics.

[26]  M. Krausz,et al.  Maintenance treatment of opiate addicts in Germany with medications containing codeine--results of a follow-up study. , 1998, Addiction.

[27]  P. Solomon,et al.  Truncated recurrent event survival models for methadone data. , 1997, Biometrics.

[28]  Y I Hser,et al.  Drug treatment careers. A conceptual framework and existing research findings. , 1997, Journal of substance abuse treatment.

[29]  A. Forbes,et al.  Double blind trial of repeated treatment with transdermal nicotine for relapsed smokers , 1995, BMJ.

[30]  Gregory E. Simon,et al.  A Chronic Disease Score with Empirically Derived Weights , 1995, Medical care.

[31]  P. Grambsch,et al.  Proportional hazards tests and diagnostics based on weighted residuals , 1994 .

[32]  J. Caplehorn,et al.  Retention in methadone maintenance and heroin addicts' risk of death. , 1994, Addiction.

[33]  E H Wagner,et al.  A chronic disease score from automated pharmacy data. , 1992, Journal of clinical epidemiology.

[34]  Ana V Diez Roux,et al.  The study of group-level factors in epidemiology: rethinking variables, study designs, and analytical approaches. , 2004, Epidemiologic reviews.

[35]  R P Mattick,et al.  Buprenorphine maintenance versus placebo or methadone maintenance for opioid dependence. , 2008, The Cochrane database of systematic reviews.

[36]  S. Magura,et al.  Pre- and in-treatment predictors of retention in methadone treatment using survival analysis. , 1998, Addiction.

[37]  Alan Ross,et al.  The Effectiveness of Methadone Maintenance Treatment , 1991, Springer New York.