Abstract Body: Introduction
Arriving at the hospital after 4.5 hours of stroke onset makes a patient ineligible for intravenous thrombolytic therapy. In the U.S., pre-hospital triage is governed by each state. We aimed to understand hospital arrival times by state and race/ethnicity.

Methods
This cross-sectional observational study included adult patients with acute ischemic stroke treated at the Get With The Guidelines-Stroke (GWTG-Stroke) participating hospitals from January 2021 to August 2023. The primary outcome was the proportion of patients with onset-to-arrival (OTA)>4.5 hours. Multivariable logistic regression models were adjusted for patient- and hospital-level potential confounding factors.

Results
This study included 691,689 patients (66.2% White, 17.1% Black, 8.8% Hispanic, 3.4% Asian, and 4.4% other / undetermined), 49.8% with OTA >4.5 hours. OTA>4.5 hours occurred in 55% of Asian patients, 54% of Black patients, 52% of Hispanic patients, and 48% of White patients. Compared to White patients, Asian [adjusted odds ratio (aOR), 1.24; 95% CI 1.20-1.28], Black (aOR, 1.18; 95% CI 1.16-1.19), and Hispanic patients (aOR, 1.10; 95% CI 1.07-1.12) were more likely to present after 4.5 hours of stroke onset. The percentages of patients with OTA>4.5 hours in each race and ethnicity by state are depicted in the Figure. States with the highest percentages of OTA>4.5 hours were North Dakota for Asian patients (83%); and Vermont for Black (90%), Hispanic (100%), and White (55%) patients. After risk adjustment, compared to Texas which had the highest diversity index, states with the highest odds of OTA>4.5 hours in all patients were Vermont (1.31; 95% CI, 1.13-1.52), Mississippi (1.15; 95% CI, 1.04-1.28), North Carolina (1.15; 95% CI, 1.06-1.24) and Kentucky (1.15; 95% CI, 1.06-1.25). For the combined group of underrepresented Asian, Black, and Hispanic patients, the adjusted analysis showed that the highest odds of OTA>4.5 hours were in Vermont (5.68, 95% CI 4.30-7.51), District of Columbia (1.39, 95% CI 1.06-1.83), Utah (1.37, 95% CI 1.08-1.75) and Rhode Island (1.36, 95% CI 1.15-1.60) compared to Texas.

Conclusions
Asian, Black, and Hispanic patients are more likely to arrive after 4.5 hours of stroke onset than White patients, with a state-specific pattern. Further studies and interventions of these states and culturally tailored interventions are warranted to improve arrival times and time-dependent stroke treatment.