Inter‐rater reliability of the National Triage Scale over 11,500 simulated occasions of triage

Since its introduction in 1993, the National Triage Scale (NTS), a five‐category scale based on the optimal time to medical intervention, has been introduced into most Australasian emergency departments as the basis of triage, clinical indicators and in some departments, casemix classification. The scale is a modification of the Ipswich Triage Scale (ITS), developed in 1989. This scale was shown in separate studies in Ipswich and Perth to be reliable and valid. The NTS however, although well validated, particularly with regard to resource use, workload and admission rates, has not been formally tested for inter‐rater reliability. In this study the inter‐rater reliability of the NTS was assessed in eight Western Australian hospital emergency departments, covering teaching, non‐teaching, rural and private hospitals, using the same methodology and patient profiles as the original ITS study. One hundred and fifteen triage nurses in these hospitals triaged 100 written patient profiles using the NTS. Inter‐rater reliability was acceptable. Of the 115 respondents, 95% were within one category of the modal response for all but four patient profiles and 86% were within one category for all patient profiles. Concurrence, or the percentage of responses in the modal category, was good. For 89% of the profiles, more than 50% of trieurs agreed with the modal response. The distribution of modal responses was not significantly affected by hospital type or triage nurse experience. The inter‐rater reliability of the NTS overall was slightly better than for the ITS in 1989. Emergency physicians, hospital administrators and government authorities can be confident that this widely used scale is a reliable measure of urgency.