Modeling Prehospital Transportation for Patients With Suspected Acute Ischemic Stroke Due to Large Vessel Occlusion: A Validation Study Using the RACECAT Trial Data

BACKGROUND: – Previously, a conditional probability model was developed to determine which transport method, drip and ship (transport to the primary stroke center for thrombolysis and then transfer to an endovascular therapy center) or mothership (direct transport to an endovascular therapy center), predicts the best outcomes for patients with suspected acute ischemic stroke. We compare and validate the conditional probability model based on the RACECAT (Rapid Arterial Occlusion Evaluation in Catalan Trial [Transfer to the Local Stroke Center Versus Direct Transfer to Endovascular Center of Acute Stroke Patients With Suspected Large Vessel Occlusion in the Catalan Territory]). METHODS: – Regional and individual level comparisons were performed by applying the conditional probability model to predict the best transport method compared with actual transport and outcomes. The primary outcome was the modified Rankin Scale score at 90 days. Ordinal logistic regression was used to assess the influence of matching transport methods on 90-day modified Rankin Scale outcomes. Subanalysis was performed to evaluate outcomes of patients with hemorrhagic stroke. RESULTS: – The conditional probability model was highly consistent with the RACECAT result overall: transport method outcomes were similar. 66.1% of Catalonia was predicted to have near equivalent outcomes for drip and ship compared with mothership. Drip and ship best predicted transport in larger areas in the daytime, and mothership for larger areas in the night. There was no significant difference in 90-day modified Rankin Scale outcomes between patients with matching versus mismatched transport methods (odds ratio, 1.13 [95% CI, 0.93–1.37]). Patients with hemorrhagic stroke had worse outcomes in those predicted and randomized to mothership versus those predicted to mothership and randomized to drip and ship (odds ratio, 3.53 [95% CI, 1.12–11.12]). CONCLUSIONS: – The conditional probability model for stroke transport successfully predicted the RACECAT clinical trial results, showing no difference in outcomes between drip and ship and mothership transport methods. REGISTRATION: – URL: https://www.clinicaltrials.gov; Unique identifier: NCT02795962.