The housing first model (HFM) fidelity index: designing and testing a tool for measuring integrity of housing programs that serve active substance users

BACKGROUND The Housing First Model (HFM) is an approach to serving formerly homeless individuals with dually diagnosed mental health and substance use disorders regardless of their choice to use substances or engage in other risky behaviors. The model has been widely diffused across the United States since 2000 as a result of positive findings related to consumer outcomes. However, a lack of clear fidelity guidelines has resulted in inconsistent implementation. The research team and their community partner collaborated to develop a HFM Fidelity Index. We describe the instrument development process and present results from its initial testing. METHODS The HFM Fidelity Index was developed in two stages: (1) a qualitative case study of four HFM organizations and (2) interviews with 14 HFM "users". Reliability and validity of the index were then tested through phone interviews with staff members of permanent housing programs. The final sample consisted of 51 programs (39 Housing First and 12 abstinence-based) across 35 states. RESULTS The results provided evidence for the overall reliability and validity of the index. CONCLUSIONS The results demonstrate the index's ability to discriminate between housing programs that employ different service approaches. Regarding practice, the index offers a guide for organizations seeking to implement the HFM.