Impacts of the introduction of a triage system in Japan: a time series study.

The aim of the present study was to measure and compare the effectiveness of nursing triage before and after introduction of the Japanese Triage and Acuity Scale (JTAS), the Japanese version of the Canadian Triage and Acuity Scale (CTAS), during emergency treatment. Surveys of triage nurses and emergency physicians were conducted before and after JTAS introduction. Respondents were triage nurses (before 112 cases, after 94 cases), emergency physicians (before 50, after 41), and triaged patients (before 1057, after 1025) from seven separate emergency medical facilities. The results showed that nursing triage using the JTAS shortened "time from registration to triage" by 3.8min, "triage duration" by 1min, "time from registration to physician" by 11.2min, and "waiting time perceived by patients to see a physician" by 18.6min (p<0.001). The difference in assigned level of urgency between triage nurses and emergency physicians decreased from 34.2% to 12.2% (p<0.001), over-triage decreased from 24.7% to 8.6% (p<0.001), and under-triage decreased from 9.5% to 3.6% (p<0.001). Furthermore, assessment agreement between triage nurses and emergency physicians increased significantly, from weighted κ=0.486 to weighted κ=0.820. These findings suggest that the introduction of the JTAS promoted more effective nursing triage and medical care.