Association Between Stroke Presentation During Off-Hours and Mechanical Thrombectomy.

Background: Access to mechanical thrombectomy (MT) in the United States remains limited. Given potential staffing challenges, we hypothesized that access to thrombectomy would be worse off hours. Methods: We used 2016 to 2018 all-payer claims data from all nonfederal emergency departments and acute care hospitals across 11 US states encompassing 80 million residents. Using recorded arrival times, hospital presentation was classified as on hours if it fell between 8:00 a.m. and 6:00 p.m. on weekdays and as off hours otherwise. We examined the association between off-hours arrival and MT using multiple adjusted logistic regression models. In a subset of patients with available National Institutes of Health Stroke Scale data, we performed a sensitivity analysis limited to patients who presented to a thrombectomy hub with a probable large-vessel occlusion, defined as a documented National Institutes of Health Stroke Scale score ≥12, and underwent intravenous thrombolysis. Similar analyses were performed to assess MT odds during extreme off hours, defined as midnight to 6:00 a.m., compared to 8:00 a.m. to 2:00 p.m. Results: Among 169 199 patients with ischemic stroke, the 82 784 (48.9%) who presented during off hours more often presented to thrombectomy hubs and teaching hospitals and more often received intravenous thrombolysis. Among 31 148 patients with documented National Institutes of Health Stroke Scale scores, those presenting off hours had higher scores (4 [interquartile range, 2-10] versus 2 [interquartile range, 1-9]; Conclusion: In a large, population-based sample of ischemic stroke patients across the United States, the odds of MT were similar during on and off hours. Extreme off hours seem to be associated with decreased access to treatment.