Abstract for: Operationalizing RE-AIM as a Dynamic System: A System Dynamics Simulation Model of Implementation Trajectories and Sustainability

Sustaining evidence-based interventions in complex healthcare systems remains difficult. The RE-AIM framework (Reach, Effectiveness, Adoption, Implementation, Maintenance) is widely used to evaluate population-level impact but is often applied as a static evaluation tool. This study develops a dynamic simulation model to examine how interactions among RE-AIM constructs, workforce capacity, and contextual pressures influence long-term implementation trajectories and program sustainability. We developed a system dynamics simulation model representing interactions among sites, participants, workforce capacity, and organizational processes. RE-AIM constructs were modeled as interconnected feedback structures governing reach, adoption, fidelity, effectiveness, and maintenance. Simulations were conducted over 120 months using a quarterly time step to compare sustained-support conditions with a mid-course funding-and-leadership collapse scenario. Under sustained support, adoption, implementation fidelity, effectiveness, and maintenance increased gradually and stabilized at high levels. In the collapse scenario, funding and leadership shocks triggered rapid erosion of fidelity, adoption, and organizational maintenance. Reach remained relatively high because previously enrolled participants continued to be counted, masking structural deterioration. Individual-level maintenance persisted temporarily due to delayed feedback from accumulated participant benefits. Implementation trajectories are sensitive to leadership continuity, funding stability, and workforce capacity. Dynamic interactions among RE-AIM constructs can produce nonlinear patterns of growth, erosion, or collapse that static evaluations may overlook. Simulation modeling offers a prospective learning tool for identifying early warning signals, anticipating implementation fragility, and designing strategies that strengthen resilience and long-term sustainability.