Associated Factors of Under and Over-Triage Based on The Emergency Severity Index; a Retrospective Cross-Sectional Study.

Introduction: Under-triage increases patients' risks for morbidity and mortality, whereas over-triage limits the resources available to sicker patients. This study aimed to determine the rates as well as associated factors of under-triage and over-triage in emergency department (ED), based on Emergency Severity Index (ESI) triage system. Methods: In this retrospective cross-sectional study, triage level of ED patients based on the ESI version 4, was studied during a 9-month period in 2019. Patients' ESI level, which were examined by triage nurses were reevaluated by 3 emergency physicians and the rate of correct, under-, and over-triage as well as their associated factors were analyzed. Results: 1000 cases of triage were evaluated. Triage was correct in 69.1% of cases. The rate of under-triage was 4.9%, and that of over-triage was 26.0%. Over-triage was significantly more common among patients aged 18-30 years than for those aged ≥65 years (adjusted odds ratio [OR] = 1.73; 95% confidence interval [CI]: 1.07-2.81; p = 0.026); those with traumatic injuries (adjusted OR = 1.80; 95% CI: 1.29-2.52; p = 0.001); those arriving at the hospital during the evening shift (adjusted OR = 1.42; 95% CI: 1.01-2.0; p = 0.046); patients who were hospitalized (adjusted OR = 0.35; 95% CI: 0.22-0.54; p < 0.001); and those with severe pain (adjusted OR = 0.28; 95% CI: 0.10-0.84; p = 0.023). Younger age was also significantly associated with under-triage. Patients aged 18-30 years were under-triaged more often than those aged ≥65 years (adjusted OR = 3.05; 95% CI: 1.16-8.00; p = 0.023). Conclusions: Over-triage was substantially more common than under-triage in Vajira Hospital. Factors associated with over-triage were younger age, traumatic injury, arrival time, hospital admission, and severe pain. Younger age was the only factor related to under-triage.