Accuracy of Emergency Severity Index in older adults

Abstract

Background and importance: Emergency Severity Index is a five-level triage tool in the emergency department that predicts the need for emergency department resources and the degree of emergency. However, it is unknown whether this is valid in patients aged greater than or equal to 65 years.

Objective: The aim of the study was to compare the accuracy of the Emergency Severity Index triage system between emergency department patients aged 18-64 and greater than or equal to 65 years.

Design, settings, and participants: This was a retrospective observational cohort study of adults who presented to a Finnish emergency department between 1 February 2018 and 28 February 2018. All data were collected from electronic health records.

Outcome measures and analysis: The primary outcome was 3-day mortality. The secondary outcomes were 30-day mortality, hospital admission, high dependency unit or ICU admission, and emergency department length of stay. The area under the receiver operating characteristic curve and cutoff performances were used to investigate significant associations between triage categories and outcomes. The results of the two age groups were compared.

Main results: There were 3141 emergency department patients aged 18-64 years and 2370 patients aged greater than or equal to 65 years. The 3-day mortality area under the curve in patients aged greater than or equal to 65 years was greater than that in patients aged 18-64 years. The Emergency Severity Index was associated with high dependency unit/ICU admissions in both groups, with moderate sensitivity [18-64 years: 61.8% (50.9-71.9%); greater than or equal to 65 years: 73.3% (63.5-81.6%)] and high specificity [18-64 years: 93.0% (92.0-93.8%); greater than or equal to 65 years: 90.9% (90.0-92.1%)]. The sensitivity was high and specificity was low for 30-day mortality and hospital admission in both age groups. The emergency department length of stay was the longest in Emergency Severity Index category 3 for both age groups. There was no significant difference in accuracy between age groups for any outcome.

Conclusion: Emergency Severity Index performed well in predicting high dependency unit/ICU admission rates for both 18-64 years and greater than or equal to 65-year-old patients. It predicted the 3-day mortality for patients aged greater than or equal to 65 years with high accuracy. It was inaccurate in predicting 30-day mortality and hospital admission for both age groups.