Validity of the Korean triage and acuity scale in older patients compared to the adult group

Introduction: While many patients visit the emergency department (ED) for various reasons, medical resources are limited. Therefore, various triage scale systems have been used to predict patient urgency and severity. South Korea has developed and used the Korean Triage and Accuracy Scale (KTAS) based on the Canadian classification tool. As the elderly population increases, the number of elderly patients visiting the ED also increases. However, in KTAS, there is no consideration for the elderly, and the same classification system as adults. The aim of this study is to verify the ability of KTAS to predict severity levels in the elderly group, compared to the adult group.Methods: This is a retrospective study for patients who visited the ED at two centers between February 1, 2018 and January 31, 2021. The initial KTAS level, changed level at ED discharge, general patient character, ED treatment results, in-hospital mortality, and lengths of hospital and ED stays were acquired. Area under the receiver operating characteristics (AUROC) was used to verify the severity prediction ability of the elderly group to KTAS, and logistic regression analysis was used for the prediction up-triage of KTAS.Results: The enrolled patients in the study were 87,220 in the adult group and 37,627 in the elderly group. The proportion of KTAS up-triage was higher in the elderly group (1.9 % vs. 1.2 %, p < 0.001). The AUROC for the overall admission rate was 0.686, 0.667 in the adult and elderly group, the AUROC for ICU admission was 0.842, 0.767, and the AUROC for in-hospital mortality prediction was 0.809, 0.711, indicating a decrease in the AUROC value in the elderly group. The independent factors of the up-triage predictors were old age, male gender, pulse, and ED length of stay, and old age was the most influential variable.Conclusion: KTAS was poorly associated with severity in the elderly than in adults, and it was found that up -triaging was more likely to occur in the elderly. The severity and urgency of patients over 65 years of age should not be underestimated when initially determining the triage scale.