Clinical decision making in the emergency department (ED) can have a significant impact on patient safety and health care outcomes. One type of clinical decision making is the process of emergency department triage. Within the context of the 5-level Emergency Severity Index triage system, it is not known what factors influence patient assignment by the triage nurse to ESI acuity levels 2 and 3. To increase the validity of patient assignment to levels 2 and 3, more explicit criteria are needed.

Purposes: 1) Describe factors that influence triage nurse assignment of patients to level 2 and level 3; 2) Examine the relationship between group membership (level 2 and Level 3) and specific patient factors; and 3) Describe the emergency department trajectory for patients assigned at triage to level 2 or level 3.

Methods: This prospective study used a convenience sample of 18 nurses from two large emergency departments. During the triage process, if the patient was assigned to level 2 or level 3, the nurse completed a Triage Questionnaire. The PI then continued data collection on these patients as they progressed through the emergency department experience to final diagnosis and disposition.

Results: A total of 334 Triage Questionnaires and patient charts were used for data analysis. Nurses rated patient age, vital signs, and the need for a timely intervention as significant factors influencing patient assignment to level 2, and number of expected resources as a significant factor influencing patient assignment to level 3. Influencing factors that did not reach statistical significance, but were nonetheless clinically important, included patient chief complaint, past medical history, additional symptoms other than patient chief complaint, and patient presentation. Resource use was significantly different for patients assigned to level 2 compared to level 3.

Conclusions: This study was able to identify specific, objective factors that are important in clinical decision making when determining patient severity of illness and time to treatment. Those factors could be used by less experienced nurses to assist in differentiating which patients could potentially be in a high risk situation, and should therefore be assigned to level 2 rather than level 3.