Implementation and refinement of the Emergency Severity Index

Objectives: To implement a new five-level emergency department (ED) triage algorithm, the Emergency Severity Index (ESI), into nursing practice, and v alidate the instrument with a population-based cohort using hospitalization and ED length of stay as outcome measures. Methods: The five-level ESI alg orithm was introduced to triage nurses at two university hospital EDs, and implemented into practice with reinforcement and change management strategi es. Interrater reliability was assessed by a posttest and by a series of in dependent paired patient triage assignments, and a staff survey was perform ed. A cohort validation study of all adult patients registered during a one -month period immediately following implementation was performed. Results: Eight thousand two hundred fifty-one ED patients were studied. Weighted kap pa for reproducibility of triage assignments was 0.80 for the posttest (n = 62 nurses), and 0.73 for patient triages (n = 219). Hospitalization was 28 % overall and was strongly associated with triage level, decreasing from 58 /63 (92%) of patients in triage category 1, to 12/739 (2%) in triage catego ry 5. Median lengths of stay were two hours shorter at either triage extrem e (high and low acuity) than in intermediate categories. Outcomes followed a-priori predictions. Staff nurses rated the new program easier to use, and more useful as a triage instrument than previous three-level triage. They provided feedback, which resulted in significant revisions to the algorithm and educational materials. Conclusions: Triage nurses at these two hospita ls successfully implemented the ESI algorithm and provided useful feedback for further refinement of the instrument. Emergency Severity Index triage r eproducibly stratifies patients into five groups with distinct clinical out comes.