Predictors of Attrition from a National Sample of Methadone Maintenance Patients

Background: Methadone substitution therapy is an effective harm reduction treatment method for opioid dependent persons. Ability to retain patients in methadone treatment is an accepted predictor of treatment outcomes. Objectives: The current study evaluates the roles of psychiatric comorbidity, medical comorbidity, and sociodemographic characteristics as predictors of retention in methadone treatment utilizing retrospective analysis of data from a nationwide sample of patients in methadone treatment in the VA. Methods: Data were gathered using the VA's national health services use database. A cohort of veterans with a new episode of opiate substitution in fiscal year 1999 was identified, and their continuous service use was tracked through fiscal year 2002. The sample included a total of 2,363 patients in 23 VA medical centers. Survival analysis was used to explore factors associated with retention in methadone treatment. Results: Younger age, having a serious mental illness, being African American, or having race recorded as unknown were associated with lower rates of retention in methadone treatment programs in this population of veterans (controlling for site). Conclusion: Given that extended methadone treatment is associated with improved outcomes while patients remain in treatment, more longitudinal studies using primary data collection are needed to fully explore factors related to retention. For the VA population specifically, further research is necessary to fully understand the relationship between race/ethnicity and treatment retention. Scientific Significance: This is the first retention study the authors are aware of that utilizes data from a nationwide, multisite, population of participants in methadone treatment.