Drip and Ship Versus Direct to Comprehensive Stroke Center: Conditional Probability Modeling.

Abstract

The outcome of ischemic stroke is related to the volume of brain that is infarcted, and the volume of infarction is directly related to the time to reperfusion.1 In an anterior circulation, large-vessel ischemic stroke 1.9 million neurons are lost every minute.2 Treatment efficacy is dependent on time to treatment initiation. Acute ischemic stroke is treated medically with the administration of intravenous alteplase. Recent results of several randomized trials established the efficacy of endovascular treatment in ischemic stroke.3–8 The facilities and expertise needed for endovascular procedures are only available at endovascular capable centers (ECCs), which are typically tertiary care hospitals. Medical treatment with alteplase is more widely available. This creates 2 options for prehospital destination decision-making for suspected stroke: (1) transport the patient directly to the nearest ECC to receive alteplase and, if appropriate, immediate endovascular therapy even though this might mean bypassing a closer non-ECC (nECC; mothership model); or (2) transport the patient to the nearest nECC to receive alteplase and then transfer the patient to the nearest ECC for endovascular therapy (drip and ship model). There are advantages and disadvantages to each of these options, and it is currently unknown which of these options will lead to the highest probability of good outcome for the patient. The RACECAT trial in Barcelona, Spain, is planned to directly address this question (NCT02795962). Herein, we propose a methodology for addressing this problem using statistical probability modeling and suggest a candidate model for evaluation. ### Assumptions We make several assumptions in the development of the prediction models (Table I in the online-only Data Supplement). First, these models apply when there is uncertainty on which transport and treatment decision to choose. Second, the nECC is the closest treatment center to the location of stroke occurrence. If an ECC is the …