The Manchester Triage System's performance in clinical risk prioritisation of patients presenting with headache in emergency department: A retrospective observational study.

OBJECTIVE Non-traumatic headache is a frequent reason for visits to the emergency department (ED). We evaluated the performance of the Manchester Triage System (MTS) in prioritising patients presenting to the ED with non-traumatic headache. METHODS In this single-centre observational retrospective study, we compared the association of MTS priority classification codes with a final diagnosis of a severe neurological condition requiring timely management (ischaemic or haemorrhagic stroke, subarachnoid haemorrhage, cerebral sinus venous thrombosis, central nervous system infection or brain tumour). The study was conducted and reported according to the STROBE statement. The overall prioritisation accuracy of MTS was estimated by the area under the receiver operating characteristic (ROC) curve. The correctness of triage prediction was estimated based on the "very urgent" MTS grouping. An undertriage was defined as a patient with an urgent and severe neurological who received a low priority/urgency MTS code (green/yellow). RESULTS Over 30 months, 3002 triage evaluations of non-traumatic headache occurred (1.7% of ED visits). Of these, 2.3% (68/3002) were eventually diagnosed with an urgent and severe neurological condition. The MTS had an acceptable prioritisation accuracy, with an area under the ROC curve of 0.734 (95% CI 0.668-0.799). The sensitivity of the MTS for urgent codes (yellow, orange and red) was 79.4% (95% CI 74.5-84.3), with a specificity of 54.1% (95% CI 52.9-55.3). The triage prediction was incorrect in only 6.3% (190/3002) of patients with headache. CONCLUSION The MTS is a safe and accurate tool for prioritising patients with non-traumatic headache in the ED. However, MTS may need further specific tools for evaluating the more complicated symptoms and for correctly identifying patients with urgent and severe underlying pathologies. RELEVANCE TO CLINICAL PRACTICE The triage nurse using MTS may need additional tools to improve the assessment of patients with headache, although MTS provides a good safety profile.