Validation of a modified South African triage scale in a high-resource setting: a retrospective cohort study

Triage systems are widely used in emergency departments, but are not always validated. The South African Triage Scale (SATS) has mainly been studied in resource-limited settings. The aim of this study was to determine the validity of a modified version of the SATS for the general population of patients admitted to an ED at a tertiary hospital in a high-income country. The secondary objective was to study the triage performance according to age and patient categories. We conducted a retrospective cohort study of patients presenting to the Emergency Department of Haukeland University Hospital in Norway during a four-year period. We used short-term mortality, ICU admission, and the need for immediate surgery and other interventions as the primary endpoints. A total of 162,034 emergency department visits were included in the analysis. The negative predictive value of a low triage level to exclude severe illness was 99.1% (95% confidence interval: 99.0-99.2%). The level of overtriage, defined as the proportion of patients assigned to a high triage level who were not admitted to the hospital, was 4.1% (3.9-4.2%). Receiver operating characteristic (ROC) curves showed an area under the ROC for the detection of severe illness of 0.874 (95% confidence interval: 0.870-0.879) for all patients and 0.856 (0.837-0.875), 0.884 (0.878-0.890) and 0.869 (0.862-0.876) for children, adults and elderly individuals respectively. We found that the modified SATS had a good sensitivity to identify short-term mortality, ICU admission, and the need for rapid surgery and other interventions. The sensitivity was higher in adults than in children and higher in medical patients than in surgical patients. The over- and undertriage rates were acceptable.