Can the Repetitive Saliva Swallow Test Predict Airway Invasion in All Cause Dysphagia?

Abstract

The repetitive saliva swallow test (RSST) is a simple, noninvasive screening tool for oropharyngeal dysphagia, validated to detect aspiration in individuals with neurogenic dysphagia. This study aims to evaluate the diagnostic properties of the RSST in predicting airway invasion in an all-cause dysphagia population using fiberoptic endoscopic evaluation of swallowing (FEES) as the gold standard. A retrospective review including 87 adult outpatients from a dysphagia clinic was conducted. Each patient underwent both RSST and FEES. The primary outcome measure was the RSST's diagnostic performance against FEES-determined airway invasion (penetration-aspiration scale, PAS ≥ 3). The study cohort had a median RSST score of 5, and 32% demonstrated airway invasion on FEES. Higher RSST scores were associated with a lower likelihood of airway invasion (OR: 0.79, p = 0.03). On receiver operating characteristic curve analysis, RSST had an area under the curve of 0.64, with an optimal cutoff of ≤ 6 swallows, yielding 89% sensitivity and 34% specificity. The RSST demonstrates statistical compatibility for airway invasion screening in an all-cause dysphagia population. However, its high cutoff values hinder its clinical utility due to modest specificity.