Reliability of Korean Triage and Acuity Scale: Interrater Agreement between Two Experienced Nurses by Real-Time Triage and Analysis of Influencing Factors to Disagreement of Triage Levels

BACKGROUND: All emergency centers in Korea use the Korean Triage and Acuity Scale (KTAS) as their initial triage tool. However, KTAS has been used without verification of its reliability. In this study, we assess the interrater agreement of KTAS by two independent nurses in real-time and analyse the factors which have an effect on the disagreement of KTAS levels. METHODS: This study was a prospective observational study conducted with patients who visited an emergency department (ED). Two teams, each composed of two nurses, triaged patients and recorded KTAS level and the main complaint from the list of 167 KTAS complaints, as well as modifiers. Interrater reliability between the two nurses in each team was assessed by weighted-kappa. Pearson's χ(2) test was conducted to determine if there were differences between each nurse's KTAS levels, depending on whether they chose the same complaints and the same modifiers or not. RESULTS: The two teams triaged a total of 1,998 patients who visited the ED. Weighted-kappa value was 0.772 (95% confidence interval [CI], 0.750–0.794). Patients triaged by different chosen complaints showed (38.0%) higher inconsistency rate in KTAS levels than those triaged by the same complaint (10.9%, P < 0.001). When nurses chose the same complaint and different modifiers, the ratio of different levels (50.5%) was higher than that of the same complaint and same modifier (8.1%, P < 0.001). CONCLUSION: This study showed that KTAS is a reliable tool. Selected complaints and modifiers are confirmed as important factors for reliability; therefore, selecting them properly should be emphasized during KTAS training courses.