An evidence-based co-occurring disorder intervention in VA homeless programs: outcomes from a hybrid III trial

Evidence-based treatment for co-occurring disorders is needed within programs that serve homeless Veterans to assist with increasing engagement in care and to prevent future housing loss. A specialized co-occurring disorders treatment engagement intervention called Maintaining Independence and Sobriety Through Systems Integration, Outreach and Networking - Veterans Edition (MISSION-Vet) was implemented within the Housing and Urban Development - Veterans Affairs Supportive Housing (HUD-VASH) Programs with and without an implementation strategy called Getting To Outcomes (GTO). While implementation was modest for the GTO group, no one adopted MISSION in the non-GTO group. This paper reports Veteran level outcome data on treatment engagement and select behavioral health outcomes for Veterans exposed to the MISSION-Vet model compared to Veterans without access to MISSION-Vet.

This hybrid Type III trial compared 81 Veterans in the GTO group to a similar group of 87 Veterans with mental health and substance use disorders from the caseload of staff in the non-GTO group. Comparisons were made on treatment engagement, negative housing exits, drug and alcohol abuse, inpatient hospitalizations, emergency department visits and income level over time, using mixed-effect or Cox regression models.

Treatment engagement, as measured by the overall number of case manager contacts with Veterans and others (e.g. family members, health providers), was significantly higher among Veterans in the GTO group (B = 2.30, p = .04). Supplemental exploratory analyses between Veterans who received "higher" and "lower" intensity MISSION-Vet services in the GTO group failed to show differences in alcohol and drug use, inpatient hospitalization and emergency department use.

Despite modest MISSION-Vet fidelity among staff treating Veterans in the GTO group, differences were found in treatment engagement. However, this study failed to show differences in alcohol use, drug use, mental health hospitalizations and negative housing exits over time among those Veterans receiving higher intensity MISSION-Vet services versus low intensity services. This project suggests that MISSION-Vet could be used in HUD-VASH to increase engagement among Veterans struggling with homelessness, a group often disconnected from care.

Clinicaltrials.gov, registration number: NCT01430741 , registered July 26, 2011.