The Repetitive Saliva Swallowing Test (RSST) as a Screening Test of Functional Dysphagia. (2). Validity of RSST.

Abstract

We developed the "Repetitive Saliva Swallowing Test (RSST)" to safely and simply screen patients for functional dysphagia. We examined 131 patients with functional dysphagia by using RSST and compared its findings with those of videofluorography (VF) to establish the validity of RSST. RSST findings had a high correlation with those of VF. Especially in examining aspiration, there was statistically significant difference between patients with RSST≥3/30sec and those with RSST<3. We concluded that the criteria of twice or less per 30sec, which was set as the screening value of RSST, was appropriate. The sensitivity and specificity of RSST in screening aspiration were 0.98 and 0.66 respectively, proving that RSST had very high sensitivity. It seems reasonable to set the screening value of RSST at twice or less per 30sec. When evaluating dysphagia, it seems appropriate to perform RSST first. When RSST presents the value of twice or less per 30sec, clinical history and medical information of the patients should be investigated, and, if necessary, VF should be performed to decide specific treatment.