Accuracy of the NICE Traffic Light system for detecting serious illness in acutely unwell children presenting to general practice: a retrospective cohort study

Background: The NICE Traffic Light system was created to facilitate the assessment of unwell children in primary care. No studies have evaluated this tool in UK general practice. Aim: To evaluate the accuracy of this system for detecting serious illness in children presenting to general practice. Design and Setting: Retrospective diagnostic accuracy study, using a cohort of acutely unwell children under five years presenting to general practice in England and Wales. Method: The Traffic Light categories of 6,703 children were linked with hospital data to identify admissions and diagnoses. The sensitivity and specificity of these categories were calculated against the reference standard: a hospital diagnosed serious illness within seven days of GP consultation, measured using ICD-10 codes. Results: 2,116 (31·6%) children were categorised as red; 4,204 (62·7%) amber; and 383 (5·7%) green. 139 (2·1%) children were admitted to hospital within seven days of consultation, of whom 17 (12·2%; 0·3% overall) had a serious illness. The sensitivity of the ‘red’ category (vs. amber/green) was 58·8% (95% confidence interval: 32·9% to 81·6%) and the specificity 68·5% (67·4% to 69·6%). The sensitivity and specificity of ‘red’ and ‘amber’ combined (vs. green) was 100% (80·5% to 100%) and 5·7% (5·2% to 6·3%) respectively. Conclusion: The Traffic Light system cannot accurately detect children admitted with a serious illness, nor those not seriously ill who can be managed at home. This system is not suitable for use as a clinical tool in general practice. Further research is required to update or replace the Traffic Light system.