Silent aspiration lacks clinical manifestations and easily leads to complications such as aspiration pneumonia. At present, there is a lack of research on the current status of silent aspiration and its influencing factors in patients with dysphagia in China.

To understand the current status of silent aspiration among patients with dysphagia in China and to explore the influencing factors of silent aspiration.

This study was a cross-sectional survey. 212 patients with dysphagia were selected as study subjects among the rehabilitation, neurosurgery, and neurology departments of four hospitals in Nanjing (the First Affiliated Hospital with Nanjing Medical University, the Affiliated Jiangning Hospital of Nanjing Medical University, the Affiliated Sir Run Run Hospital of Nanjing Medical University, and the Dongshan Hospital of Jiangning District of Nanjing) by the convenience sampling method from December 2022 to January 2024. The basic data of the patients were recorded, and the Eating Assessment Questionnaire (EAT-10) score and Barthel Index were used to assess dysphagia risk and ability to perform activities of daily living. Fluoroscopic Fluorescence Swallowing Screening (VFSS) or Flexible Endoscopic Swallowing Function Examination (FEES) was used to diagnose whether the patient experienced aspiration and the type of aspiration. In this study, all patients who had no aspiration during swallowing were categorized as the no aspiration group, all patients who had at least 1 silent aspiration during swallowing were categorized as the silent aspiration group, and all patients who had at least 1 overt aspiration but no silent aspiration during swallowing were categorized as the overt aspiration group. Multivariate Logistic regression analysis was used to explore the influencing factors of silent aspiration and overt aspiration.

Silent aspiration accounted for 47.2% (100/212), overt aspiration 13.2% (28/212), and no aspiration 39.6% (84/212) of patients with dysphagia. Among the 128 patients with aspiration, 78.1% (100/128) were silent aspiration and 21.9% (28/128) were overt aspiration. The results of multivariate Logistic regression analysis showed that the EAT-10 score (OR=1.076, 95%CI=1.028-1.126, P=0.002), gender (female as control, OR=2.231, 95%CI=1.103-4.509, P=0.025), and conscious status (impaired consciousness as control, OR=0.334, 95%CI=0.123-0.911, P=0.032) were influential factors for silent aspiration. EAT-10 scores (OR=1.113, 95%CI=1.046-1.184, P=0.001) and poor self-assessed health (OR=0.194, 95%CI=0.041-0.923, P=0.039) were influential factors for overt aspiration.

The prevalence of silent aspiration is higher among patients with dysphagia and the risk of silent aspiration increases with higher EAT-10 scores, in males, and in those with impaired consciousness.