Wang J, Gong X, Zhong W, et al. - Researchers designed a 4‐item Stroke Scale (4I‐SS) based on the items of National Institutes of Health Stroke Scale and medical history and identified it as an effective and simple tool to identify large vessel occlusion stroke (LVOS) and its cause.

• The derivation and validation cohort included 1,630 and 11 440 patients, respectively.

• Gaze, level of consciousness, arm weakness, and atrial fibrillation were incorporated in the 4I‐SS.

• In the validation cohort, the 4I‐SS ≥ 4 had Youden Index, area under the curve, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy to predict LVOS of 0.494, 0.800, 0.657, 0.837, 0.600, 0.868, and 0.788, respectively, and the 4I‐SS ≥ 7 had values of 0.200, 0.669, 0.229, 0.971, 0.066, 0.974, and 0.899, respectively, to predict basilar artery occlusion.

• Relative to previously published scales, higher Youden Index and area under the curve were generated for predicting LVOS.

• When the 4I‐SS score, including atrial fibrillation, was ≥ 6, its accuracy was 0.922 for predicting whether cardiogenic embolism was the cause, and when it was ≥ 7, its accuracy was 0.590 for predicting that the occluded vessel was intracranial internal carotid artery or M1 segment of the middle cerebral artery.