Treatment setting and baseline substance use severity interact to predict patients' outcomes

Aims This study tested the hypothesis that patients with more severe substance use disorders (SUDs) at intake respond better when treated in more structured and intensive settings (i.e. in-patient/residential versus out-patient), whereas patients with less severe SUD problems have similar outcomes regardless of treatment setting. Design, setting and participants Up to 50 new patients were selected randomly from each of a random and representative sample of 50 Department of Veterans Affairs (VA) SUD treatment programs (total n = 1917 patients), and were followed- up an average of 6.7 months later (n = 1277). Measures Patients completed a brief self- report version of the Addiction Severity Index (ASI) at baseline and at follow-up. Findings In mixed- model regression analyses, baseline substance use severity predicted follow-up substance use severity and there were no main effects of treatment setting. However, interaction effects were found, such that more severe patients experienced better alcohol and drug outcomes following in-patient/residential treatment versus out-patient treatment; on the other hand, patients with lower baseline ASI drug severity had better drug outcomes following out-patient treatment than in-patient treatment. Treatment setting was unrelated to alcohol outcomes in patients with less severe ASI alcohol scores. Conclusions Results provide some support to the matching hypothesis that for patients who have higher levels of substance use severity at intake, treatment in in-patient/residential treatment settings is associated with better outcomes than out-patient treatment. More research needs to be conducted before in-patient/residential settings are further reduced as a part of the SUD continuum of care in the United States.