Aims This study examined systematically how predictors of substance use disorder (SUD) treatment outcome worked together over time and identified mediators and moderators of outcome.
Design The MacArthur model was applied in this naturalistic study to identify how baseline, discharge and 1-year follow-up factors worked together to predict 4-year improvement in substance-related problems.
Setting Eighty-eight community residential facilities were selected based on geographic representativeness, number of patient referrals and type of treatment orientation.
Participants Of 2796 male patients who completed intake assessments, 2324 were assessed at the 1-year follow-up and 2023 at the 4-year follow-up.
Measurements Self-report measures of symptom severity, functioning, social resources and coping, treatment and involvement in Alcoholics Anonymous (AA) were collected at baseline and at 1- and 4-year follow-ups. Provider-rated treatment participation measures were obtained at discharge.
Findings Greater substance use severity, more psychiatric symptoms, more prior arrests and stronger belief in AA-related philosophy at treatment entry predicted improvement significantly in substance-related problems 4 years later. At the 1-year follow-up, being employed and greater use of AA-related coping predicted outcome significantly. AA-related coping at 1 year mediated the relationship partially between belief in AA philosophy at treatment entry and 4-year outcome.
Conclusions The findings highlight the unique and positive impact of AA involvement on long-term SUD treatment outcome and extend understanding of why AA is beneficial for patients.