 This study developed and validated a method for converting Japan coma scale, JCS, scores to Glasgow coma scale, GCS, scores in adult patients visiting emergency departments in Japan. The conversion table was based on median GCS values, and the concordance rate between JCS and GCS was over 90% in the general adult patient population. This article was authored by Miki Onakajima, Yohei Okada, Tomohiro Senu, and others.