To assess the performance of the newly implemented Canadian Emergency Department Triage and Acuity Scale (CTAS) triage system in a redesigned 200-bed community hospital emergency department (ED) and to evaluate the predictive validity of CTAS in this setting.

Triage system performance was analyzed on the basis of 4 quality indicators: time to triage; triage duration; proportion of patients who left without being seen by a physician; and waiting time to nurse and physician, stratified by triage level and reported as fractile response rates. The predictive validity of CTAS was evaluated by investigating the relationship between CTAS level, hospitalization index, ED length of stay (LOS) and diagnostic test utilization.

During the study period, 32 574 patients were triaged and 32 261 were eligible for study. Eighty-five percent were triaged within 10 minutes, and 98% had a triage duration of ≤5 minutes. Waiting times to nurse and physician were within CTAS time objectives in 96.3% and 92.3% of cases respectively. The left without being seen (LWBS) rate was 0.96%. Hospitalization rates were compatible with CTAS standards for adults in Levels I, II, III and V and for children in Level V. Median LOS and laboratory test utilization were highly correlated with CTAS Levels II to V (p < 0.01), and similar correlation between triage acuity and imaging utilization was noted in adult patients with non-traumatic non-musculoskeletal complaints (p < 0.01).

The CTAS is adaptable to countries beyond Canada and its operating objectives are achievable. Time to triage and fractile response rates can be considered indicators of triage quality and ED performance. CTAS is a valid instrument for predicting admission rates, hospital LOS and diagnostic utilization.