Predictors of opiate agonist treatment retention among injection drug users referred from a needle exchange program

Aims: The aim of this study was to examine the effect of a case management intervention on retention in opiate agonist therapy among injection drug users (IDUs) referred from a needle exchange program (NEP). Design, intervention, participants, and setting: A randomized trial of a strengths-based case management intervention versus passive referral (control) was conducted among NEP attendees requesting and receiving referrals to subsidized, publicly funded opiate agonist treatment programs in Baltimore, MD. Measurements: Multivariable Cox regression models were used to identify predictors of treatment retention using an ecological model approach, taking into account factors at the individual, social, and environmental level. Findings: Of 245 IDUs, 127 (51.8%) entered opiate agonist treatment, for whom median retention was 7.9 months. The intervention was not associated with longer retention (p = .91). Individual-level factors predictive of shorter retention included being employed and greater levels of psychiatric distress. Participants who had prior treatment experience and multiple treatment requests were retained significantly longer. Social factors adversely affecting treatment retention included unstable housing and buying drugs for others. Living further away from the treatment site was an environmental barrier that negatively affected treatment retention. Conclusions: Multilevel interventions that address individual, social, and environmental factors are necessary to improve substance abuse treatment retention and treatment outcomes among IDUs referred from NEP.