Diagnostic accuracy of ultrasound examination in detecting aspiration and pharyngeal residue in patients with dysphagia: A systematic review and meta-analysis

Aim: To estimate diagnostic accuracy of ultrasonography for detecting aspiration and pharyngeal residue in patients with dysphagia. Methods: A systematic search was conducted in MEDLINE (via PubMed), CINAHL, EMBASE, Ichushi-Web, and Cochrane Library databases to identify articles that showed diagnostic accuracy of ultrasonography for detecting aspiration and residue published in English and Japanese until August 2019. Cross-sectional studies, case–control studies, and cohort studies were included. The diagnostic accuracy results were extracted and the pooled estimated sensitivity and specificity were calculated. The risk of bias of the studies was assessed using the Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies 2. The certainty of the evidence was assessed using the Grades of Recommendation Assessment, Development, and Evaluation methodology. Results: Five studies were included in this review. The pooled estimated sensitivity and specificity for detecting aspiration were 0.82 (95% CI: 0.72–0.89) and 0.87 (95% CI: 0.81–0.92), respectively. One study was included that evaluated ultrasound assessments of pharyngeal residue. The sensitivity and specificity were 0.62 (95% CI: 0.32–0.86) and 0.67 (95% CI: 0.22–0.96), respectively. The certainty of the evidence was low and very low for the diagnostic accuracy of aspiration and pharyngeal residue, respectively. Conclusion: Ultrasound is a non-invasive method with good sensitivity and specificity in detecting aspiration as well as reference standards. While risk of bias and small number of studies limited the strength of this systematic review, our results suggested that ultrasound examination was useful as a bedside screening tool for detecting aspiration.