Simplified Prehospital Prediction Rule to Estimate the Likelihood of 4 Types of Stroke: The 7-Item Japan Urgent Stroke Triage (JUST-7) Score

Objective Prehospital prediction models to estimate the likelihood of several types of stroke (large vessel occlusion [LVO], intracranial hemorrhage [ICH], and subarachnoid hemorrhage [SAH], and other types of stroke) should be useful to transfer those with suspected stroke to appropriate facilities. We recently reported Japan Urgent Stroke Triage (JUST) score with 21 items had excellent predictive abilities, and we further tried to simplify the score with parsimonious items and comparable predictive abilities. Methods We conducted historical and prospective multicenter cohort studies at 8 centers from June 2015 to March 2018. We developed the prediction rules with select variables from JUST score for LVO, ICH, SAH and other types of stroke in 2236 patients with suspected stroke in historical derivation cohort. We validated the developed prediction rules in 964 patients in prospective validation cohort. Results There were 1150 stroke, including 235 LVO, 352 ICH, 107 SAH and 456 other types of stroke in the derivation cohort. We developed the scores with 7 items (high blood pressure, arrhythmia, conjugate deviation, headache, dysarthria, disturbance of consciousness, paralysis of upper limbs) and the developed scores had area under the receiver-operating curve (AUC) of 0.84 for any type of stroke, 0.89 for LVO, 0.79 for ICH, and 0.90 for SAH in the derivation cohort. There were 490 stroke, including 102 LVO, 138 ICH, 28 SAH and 222 other types of stroke in the validation cohort. The scores well discriminated these strokes in the validation cohort (AUC of 0.76 for any type of stroke; 0.81 for LVO, 0.73 for ICH, and 0.85 for SAH). Conclusions The simplified 7-item JUST (JUST-7) score had good predictive ability and can help healthcare providers to estimate the likelihood of different types of stroke and decide the referral hospital.