Accuracy of the NICE traffic light system in children presenting to general practice: a retrospective cohort study

BACKGROUND: The National Institute for Health and Care Excellence (NICE) traffic light system was created to facilitate the assessment of unwell children in primary care. To the authors’ knowledge, no studies have validated 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: A retrospective diagnostic accuracy study was undertaken, using a cohort of acutely unwell children aged <5 years presenting to general practice in England and Wales. METHOD: The traffic light categories of 6703 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 7 days of GP consultation, measured using International Classification of Diseases, 10th Revision codes. RESULTS: In total, 2116 (31.6%) children were categorised as ‘red’; 4204 (62.7%) as ‘amber’; and 383 (5.7%) as ‘green’. There were 139 (2.1%) children who were admitted to hospital within 7 days of consultation, of whom 17 (12.2%; 0.3% overall) had a serious illness. The sensitivity of the red category (versus amber and green) was 58.8% (95% confidence interval [CI] = 32.9 to 81.6) and the specificity 68.5% (95% CI = 67.4 to 69.6). The sensitivity and specificity of red and amber combined (versus green) was 100% (95% CI = 80.5 to 100) and 5.7% (95% CI = 5.2 to 6.3), respectively. CONCLUSION: The NICE traffic light system did not accurately detect children admitted with a serious illness, nor those not seriously ill who could have been 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 system.