Comparing two implementation strategies for implementing and sustaining a case management practice serving homeless-experienced veterans: a protocol for a type 3 hybrid cluster-randomized trial

BACKGROUND: The Veterans Health Administration (VA) Grant and Per Diem case management “aftercare” program provides 6 months of case management for homeless-experienced veterans (HEVs) undergoing housing transitions. To standardize and improve aftercare services, we will implement critical time intervention (CTI), an evidence-based, structured, and time-limited case management practice. We will use two strategies to support the implementation and sustainment of CTI at 32 aftercare sites, conduct a mixed-methods evaluation of this implementation initiative, and generate a business case analysis and implementation playbook to support the continued spread and sustainment of CTI in aftercare. METHODS: We will use the Replicating Effective Programs (REP) implementation strategy to support CTI implementation at 32 sites selected by our partners. Half (n=16) of these sites will also receive 9 months of external facilitation (EF, enhanced REP). We will conduct a type 3 hybrid cluster-randomized trial to compare the impacts of REP versus enhanced REP. We will cluster potential sites into three implementation cohorts staggered in 9-month intervals. Within each cohort, we will use permuted block randomization to balance key site characteristics among sites receiving REP versus enhanced REP; sites will not be blinded to their assigned strategy. We will use mixed methods to assess the impacts of the implementation strategies. As fidelity to CTI influences its effectiveness, fidelity to CTI is our primary outcome, followed by sustainment, quality metrics, and costs. We hypothesize that enhanced REP will have higher costs than REP alone, but will result in stronger CTI fidelity, sustainment, and quality metrics, leading to a business case for enhanced REP. This work will lead to products that will support our partners in spreading and sustaining CTI in aftercare. DISCUSSION: Implementing CTI within aftercare holds the potential to enhance HEVs’ housing and health outcomes. Understanding effective strategies to support CTI implementation could assist with a larger CTI roll-out within aftercare and support the implementation of other case management practices within and outside VA. TRIAL REGISTRATION: This project was registered with ClinicalTrials.gov as “Implementing and sustaining Critical Time Intervention in case management programs for homeless-experienced Veterans.” Trial registration NCT05312229, registered April 4, 2022.