Outcomes of the triage process in Croatian emergency departments: a retrospective study using the Australasian Triage Scale

Aim: To evaluated the effectiveness of the Australasian Triage Scale (ATS) in Croatian emergency departments by analyzing hospitalization, mortality, and discharge rates across different triage categories. Design: A retrospective cohort study. Methods: A total of 68,165 adult patients treated in the emergency department of the Clinical Hospital Center, Rijeka between January 1 and December 31, 2023. Patients were triaged into Australasian Triage Scale levels 1 to 5, and their outcomes–including hospital admissions, discharges, and mortality – were analyzed. Statistical significance was assessed using chi-square tests for categorical variables, with Bonferroni-adjusted post-hoc pairwise comparisons. Age differences across categories were analyzed using ANOVA and Kruskal-Wallis tests. A p-value of<0.05 was considered statistically significant. Results: Significant differences in outcomes were observed across all Australasian Triage Scale categories (p<0.001). Category 1 patients had the highest mortality rate (74.6%) and the lowest hospitalization rate (4.6%), reflecting the critical nature of these cases. Category 2 showed a mortality rate of 17.7% and a hospitalization rate of 26.3%. Category 3, which accounted for 45% of the sample, had the highest hospitalization rate (48.4%) with a lower mortality rate (6.9%), indicating appropriate triage of serious but non-immediately life-threatening cases. Categories 4 and 5 exhibited low mortality (0.8% and 0%) and high discharge rates (88.6% and 89.9%), supporting the accurate identification of lower-acuity patients. Post-hoc comparisons confirmed significant differences in hospitalization and mortality between most Australasian Triage Scale levels (p<0.001), except between categories 4 and 5, in which no statistically significant difference was found (p=0.169). Median time to treatment corresponded to clinical urgency, ranging from 0 minutes in ATS 1 to 24 minutes inATS 5, indicating timely initiation of care. Conclusion: The Australasian Triage Scale effectively stratifies patients basedonclinical urgency, facilitating appropriate resource allocation and timely intervention. However, the high proportion ofnon-urgent visits contributes to emergency department overcrowding. These findings underscore the need for public education on appropriate use of emergency departments and stronger integration of primary healthcare services to enhance triage efficiency.