Abstract WP302: Simulating the Impact of Reducing Door-in-Door-out Times for Acute Stroke Transfers

Introduction: Some acute stroke (AS)patients require transfer to comprehensive stroke centers (CSCs) for time-sensitive, advanced treatments that lead to better outcomes. However, door-in-door-out (DIDO). PSC DIDO processes at primary stroke centers (PSCs) can be prolonged and result in delay or failure to deliver the advanced treatments at the CSC. We simulated the impact of reducing PSC DIDO times on the rate of inappropriate transfers to CSCs, a potential consequence of such efforts. Methods: Clinicians from3Chicago-area CSCs and 3 affiliated PSCs and the two main ambulance providers created a PSC DIDO process map Patient-level data from the 3 PSCs (N-108) and estimates from the literature were used to determine the distribution, range, or proportion of each step in the process. Datainputs were varied using Python™ in simulations with 100 replications. Outputswere DIDO time, % patients transferred to CSC, and % inappropriate CSC transfers. Sensitivity analyses assessed most impactful factors on DIDO time. Results: Three key decision points for transfer of an AS patient to a CSC were identified: (1) After stroke code activation; (2) After telestroke consultation; and (3) Post-tPA administration(most common current process). The figureshows that increasing PSC transfer ratesimmediately after stroke code activation by 5% decreased DIDO time by 10 minutes (11%), while increasing the inappropriate CSC transfer rate by 4%. Sensitivity analyses show that total DIDO time is most sensitive to the proportion of PSC hemorrhagic strokes, accuracy of AS detection at triage, and proportion of AS patients arriving by EMS. Conclusions: A strategy of earlier detection of acute stroke at triage, followed rapidly by stroke code activation and streamlined transfer of AS patients is likely to benefit from CSC care is predicted to a large impact on DIDO times, with a very small trade-off in increasing inappropriate transfers.