Diagnostic validity of methods for assessment of swallowing sounds: a systematic review

Abstract Introduction: Oropharyngeal dysphagia is a highly prevalent comorbidity in neurological patients and presents a serious health threat, which may lead to outcomes of aspiration pneumonia, ranging from hospitalization to death. This assessment proposes a non-invasive, acoustic-based method to differentiate between individuals with and without signals of penetration and aspiration. Objective: This systematic review evaluated the diagnostic validity of different methods for assessment of swallowing sounds, when compared to videofluroscopy swallowing study to detect oropharyngeal dysphagia. Methods: Articles in which the primary objective was to evaluate the accuracy of swallowing sounds were searched in five electronic databases with no language or time limitations. Accuracy measurements described in the studies were transformed to construct receiver operating characteristic curves and forest plots with the aid of Review Manager v. 5.2 (The Nordic Cochrane Centre, Copenhagen, Denmark). The methodology of the selected studies was evaluated using the Quality Assessment Tool for Diagnostic Accuracy Studies-2. Results: The final electronic search revealed 554 records, however only 3 studies met the inclusion criteria. The accuracy values (area under the curve) were 0.94 for microphone, 0.80 for doppler, and 0.60 for stethoscope. Conclusion: Based on limited evidence and low methodological quality because few studies were included, with a small sample size, from all index testes found for this systematic review, doppler showed excellent diagnostic accuracy for the discrimination of swallowing sounds, whereas microphone-reported good accuracy discrimination of swallowing sounds of dysphagic patients and stethoscope showed best screening test.

引言与摘要：口咽吞咽障碍（Oropharyngeal Dysphagia）是神经系统疾病患者中高流行的共病状态，可构成严重健康威胁，可能引发吸入性肺炎，病情严重程度可从需住院治疗直至死亡。本研究拟采用一种基于声学特征的非侵入式方法，区分存在吞咽渗透与误吸信号的个体与健康人群。

研究目的：本系统评价旨在评估各类吞咽声音评估方法的诊断效度，并以视频透视吞咽检查（Videofluoroscopy Swallowing Study）作为参照标准，检测口咽吞咽障碍。

研究方法：本研究在5个电子数据库中检索以评估吞咽声音诊断准确性为核心目标的文献，检索未设置语言与时间限制。借助Review Manager v.5.2软件（丹麦哥本哈根北欧科克伦中心研发），将研究中报告的准确性指标转换为受试者工作特征曲线（Receiver Operating Characteristic Curve）与森林图。采用诊断准确性研究质量评价工具-2（Quality Assessment Tool for Diagnostic Accuracy Studies-2）对纳入研究的方法学质量进行评估。

研究结果：最终电子检索共获取554条文献记录，但仅3项研究符合纳入标准。各类检测手段的准确性指标（曲线下面积，Area Under the Curve）分别为：麦克风法0.94、多普勒法0.80、听诊器法0.60。

研究结论：鉴于本次系统评价纳入的研究数量有限、样本量偏小且方法学质量偏低，现有证据显示：在本次系统评价所纳入的各类吞咽声音检测指标中，多普勒法对吞咽声音的判别具有极佳的诊断准确性；麦克风法可较好地区分吞咽障碍患者与健康人群的吞咽声音；而听诊器法则可作为最优的筛查工具。