Diagnostic accuracy of radiographs for detecting supraglottitis: a systematic review and meta‐analysis

Aim To assess the diagnostic performance of lateral radiograph of the neck for supraglottitis in adults and children. Methods Electronic database searches (including PubMed, EMBASE, CINAHL, Web of Science, and WHO International Clinical Trials Registry Platform) were carried out through July 2014. Citations of included studies and recent narrative reviews were searched. Studies that compared lateral radiograph of the neck with a reference standard of direct/indirect laryngoscopy were included. Two reviewers independently assessed the methodological quality of included studies by Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2). Results Of 2,088 potentially relevant citations, two single-gate (cohort) studies and six two-gate (case-control) studies were identified. These included studies of design are at the moderate or high risk of bias in QUADAS-2. The pooled sensitivity from bivariate random-effects regression was 92.9% (95% confidence interval [CI], 88.5-95.9%) and the pooled specificity was 89.2% (95% CI, 85.9-91.9%), but the diagnostic value would be overestimated because of selection bias in the six two-gate studies. The sensitivity and specificity of the single-gate studies were 100.0% (95% CI, 92.2-100.0%) and 30.6% (95% CI, 15.5-35.6%) in children and 81.0% (95% CI, 78.2-93.2%) and 85.7% specificity (95% CI, 78.2-93.2%) in adults. Conclusion This study determines that there are insufficient studies of lateral neck radiograph for detecting supraglottitis. Lateral radiograph of the neck seems to have moderate accuracy for detecting supraglottitis. Further approximately unbiased studies are needed to obtain more valid and reliable estimates of test accuracy.