Objectives To retrospectively evaluate the diagnostic performance of qualitative and quantitative radiographic parameters for diagnosing adult acute epiglottitis, and identify the prevalence and risk factors of false-negative neck radiography-based diagnosis of acute epiglottitis. Methods An emergency physician and a radiologist independently reviewed neck radiographs of 91 patients with laryngoscopy-confirmed acute epiglottitis and 91 control subjects between March 2010 and June 2016 for qualitative and quantitative radiographic parameters of acute epiglottitis, and concluded a diagnosis. Receiver operating characteristic (ROC) curves were constructed to assess the diagnostic performance of radiographic parameters, while independent risk factors of false-negative diagnosis were determined by multivariate logistic regression analysis. Inter-observer agreement was also calculated. Results All radiographic parameters showed good diagnostic performance with sensitivities and specificities of 33.0–80.2% and 64.8–100%, respectively. Epiglottis width (EW) > 6.3 mm showed the highest diagnostic performance (area under the ROC curve [AUC]: 0.867, sensitivity: 75.8%, specificity: 97.8%). Interobserver agreement for all radiographic parameters was excellent (range: 0.893–0.991). The lateral neck radiography-based false-negative diagnosis rate was 31.9%, and previous oral antibiotic usage was an independent risk factor of false-negative results. Conclusion EW > 6.3 mm showed the best diagnostic accuracy, facilitating a neck radiograph-based diagnosis of acute epiglottitis. However, false-negative results on neck radiograph are quite common and previous oral antibiotic usage is a risk factor. Based on the knowledge of the usefulness and risk factors of false-negative results of neck radiography, diagnostic process for acute epiglottitis using neck radiography need to be changed.
- False negative
- Risk factor