A longitudinal, retrospective registry-based validation study of RETTS©, the Swedish adult ED context version

BACKGROUND: Triage and triage related work has been performed in Swedish Emergency Departments (EDs) since the mid-1990s. The Rapid Emergency Triage and Treatment System (RETTS©), with annual updates, is the most applied triage system. However, the national implementation has been performed despite low scientific foundation for triage as a method, mainly related to the absence of adjustment to age and gender. Furthermore, there is a lack of studies of RETTS© in Swedish ED context, especially of RETTS© validity. Hence, the aim the study was to determine the validity of RETTS©. METHODS: A longitudinal retrospective register study based on cohort data from a healthcare region comprising two EDs in southern Sweden. Two editions of RETTS© was selected; year 2013 and 2016, enabling comparison of crude data, and adjusted for age-combined Charlson comorbidity index (ACCI) and gender. All patients ≥ 18 years visiting either of the two EDs seeing a physician, was included. Primary outcome was ten-day mortality, secondary outcome was admission to Intensive Care Unit (ICU). The data was analysed with descriptive, and inferential statistics. RESULTS: Totally 74,845 patients were included. There was an increase in patients allocated red or orange triage levels (unstable) between the years, but a decrease of admission, both to general ward and ICU. Of all patients, 1031 (1.4%) died within ten-days. Both cohorts demonstrated a statistically significant difference between the triage levels, i.e. a higher risk for ten-day mortality and ICU admission for patients in all triage levels compared to those in green triage level. Furthermore, significant statistically differences were demonstrated for ICU admission, crude as well as adjusted, and for adjusted data ten-day mortality, indicating that ACCI explained ten-day mortality, but not ICU admission. However, no statistically significant difference was found for the two annual editions of RETTS© considering ten-day mortality, crude data. CONCLUSION: The annual upgrade of RETTS© had no statistically significant impact on the validity of the triage system, considering the risk for ten-day mortality. However, the inclusion of ACCI, or at least age, can improve the validity of the triage system