The Effect of Human Supervision on an Electronic Implementation of the Canadian Triage Acuity Scale (CTAS).

Background: Most electronic emergency department (ED) triage systems allow nurses to modify computer-generated triage scores. It is currently unclear how this affects triage validity.

Objective: Are nurse-generated triage scores more strongly associated with rates of admission, intensive care unit (ICU) consultation, and mortality than computer-generated scores?

Methods: Retrospective observational cohort study of all adult visits to a tertiary ED. An electronic implementation of the Canadian Triage Acuity Scale (CTAS) generated a CTAS score for each visit. In some cases, the triage nurse overwrote the computer-generated CTAS score with a score they felt was more appropriate. Among visits with nurse-modified triage scores, we compared the rate of acuity-related outcomes (mortality, ICU consultation, hospital admission) in each CTAS level as categorized by nurse-generated vs. computer-generated scores.

Results: In a cohort of 229,744 patients, 19,566 (8.51%) had nurse-modified triage scores. Most modifications consisted of assigning a higher acuity triage score than recommended by the computer. Visits with triage scores 1-2 according to the nurse-generated scores had the same or higher rates of the acuity outcomes than visits that were CTAS 1-2 according to the computer-generated CTAS scores. Conversely, visits with triage scores 4-5 according to the nurse-generated scores had lower rates of the outcomes than visits that were CTAS 4-5 according to the computer-generated CTAS scores.

Conclusions: Nursing supervision of the computer-automated CTAS triage system was associated with fewer hospital admissions, ICU consultations, and deaths in the triage score 4-5 categories, suggesting a safer triage process than the automated CTAS algorithm alone.