Retention in methadone maintenance drug treatment for prescription-type opioid primary users compared to heroin users

Aims   To assess retention in methadone maintenance treatment for prescription-type opioid primary (PTOP) users compared to heroin users.
Design and participants   A retrospective cohort study was carried out to examine the association between opiate types used on 12-month retention. The study population consisted of adults admitted to one of 11 not-for-profit methadone maintenance clinics in 2004 and 2005 throughout Washington State ( n  = 2308). Logistic regression analyses with fixed effects for treatment agencies were conducted.
Measurements   Opiate use type in past 30 days: any heroin use or primary prescription opioid without heroin use. Demographics, other drugs used, self-reported medical and psychiatric concerns, social, familial and legal issues, public assistance type and housing stability were documented at intake using a comprehensive biopsychosocial instrument, the Treatment and Assessment Reports Generation Tool.
Findings   The odds of being retained in treatment for PTOP compared to heroin users not adjusting for other factors was 1.33 (95% confidence interval [CI], 1.03, 1.71). In the final logistic regression model the odds of retention for PTOP compared to heroin users was 1.25 (95% CI, 0.93, 1.67), indicating that there was no statistically significant difference in treatment retention by opiate type after adjusting for demographics, treatment agencies, other drug use, public assistance type, medical, psychiatric, social, legal and familial factors.
Conclusion   The findings of this study suggest that PTOP can be treated at methadone maintenance treatment facilities at least as effectively as heroin users in terms of treatment retention.