Date of Award


Degree Name

Doctor of Philosophy


Interdisciplinary Health Sciences

First Advisor

Dr. Amy B. Curtis

Second Advisor

Dr. Linwood Cousins

Third Advisor

Dr. Jessaca Spybrook


Co-occurring, peer, fidelity, integrated dual disorder treatment, evidence-based practice, implementation


Individuals with co-occurring illnesses are at risk for poor outcomes related to criminal justice, hospitalization, housing, and employment. High fidelity evidence-based practice models, including Integrated Dual Disorder Treatment (IDDT), are associated with significant improvements in outcomes. Although IDDT has been well-researched in small scale clinical trials, the implementation, alteration, and sustainability in real world applications over time has not been well-researched or understood. Initially, a descriptive analysis of a secondary dataset including the full population of 68 IDDT fidelity teams from 2006–2012 evaluated by the Michigan Fidelity and Assessment Team (MiFAST) in one state was completed. IDDT fidelity significantly improved from baseline fidelity review to second review and from second review to third review (p < .01). In an analysis of sustainability of IDDT, a multi-level analysis approach examined IDDT fidelity growth trajectories. Over time, teams that first adopted, later in time, had significantly higher baseline fidelity scores than early or mid-adopter teams, and later reviews had higher fidelity. However, teams varied significantly in their baseline review and growth in review between occurrences. In an evaluation of evidence-based practice alteration, the addition of peers to IDDT teams was analyzed for teams reporting on peer variables. Of these, 85% of IDDT teams incorporated a peer, and having a full-time peer was associated with significantly higher fidelity compared to teams with a part-time or no peer (p < .01). In this large sample, IDDT took time to implement to a level of high fidelity, and was sustained even with practice alteration of adding peers. Recommendations for staffing, funding, and policy are made in this study.

Access Setting

Dissertation-Campus Only

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