Validity of the Taiwan Triage and Acuity Scale in mainland China: a retrospective observational study

The Taiwan Triage and Acuity Scale (TTAS), developed for use in EDs, has been shown to be an excellent tool for triaging patients with high predictive performance, with an area under the receiver operating curve (AUROC) of 0.75. TTAS has been widely used in hospitals in Taiwan since 2010, but its utility has not been studied outside of Taiwan. Thus, the aim of this study was to evaluate the validity of using the TTAS in the ED of a tertiary hospital in mainland China to predict patient outcomes.

A retrospective observational study was performed on patients 14 years of age or older attending the ED of a tertiary hospital in mainland China between 1 January 2016 and 31 March 2016. The validity of the TTAS in predicting hospital admission, intensive care unit (ICU) admission, death, ED length of stay (LOS) and ED resource utilisation was evaluated by determining the correlation of these outcomes with the TTAS, AUROC and test characteristics.

A total of 7843 patients were included in this study. There were significant differences between the TTAS categories in disposition, ED LOS and ED resource utilisation (p<0.0001). The TTAS was significantly correlated with patient disposition at discharge, hospital admission, ICU admission and death in the ED (Kendall rank correlations were 0.254, -0.254, -0.079 and -0.071, respectively; p=0.001). The AUROCs for the prediction of hospital admissions, ICU admissions and deaths in the ED were 0.749 (95% CI 0.732 to 0.765), 0.869 (95% CI 0.797 to 0.942) and 0.998 (95% CI 0.995 to 1.000), respectively. Our results demonstrated better performance using the TTAS for predictions of ICU admission and death.

The TTAS had good validity in predicting patient outcomes and ED resource utilisation in a tertiary hospital in mainland China. Compared with the performance of the TTAS in Taiwan, our results suggest that the TTAS can usefully be applied outside of Taiwan.