We aimed to externally validate the Enhanced Detection of Edema in Malignant Anterior Circulation Stroke (EDEMA) score for predicting potentially lethal malignant edema (PLME) after stroke in a Chinese cohort and to test whether adding stroke severity to the EDEMA score could improve the predictive performance.

Patients with anterior circulation stroke, cerebral edema, National Institutes of Health Stroke Scale (NIHSS) score ≥ 8 and head computed tomography within 24 hours of onset were enrolled. The outcome of PLME was defined as death with midline shift ≥ 5 mm or decompressive hemicraniectomy. Discrimination was assessed using area under receiver operating characteristic curve (AUC). Calibration was assessed by calibration plot. Decision curve analysis (DCA) was performed to evaluate the clinical usefulness of the score. The added value of stroke severity (admission NIHSS score) was evaluated using AUC, net reclassification improvement, and integrated discrimination improvement.