Discriminant ability of the 3-ounce water swallow test to detect aspiration in amyotrophic lateral sclerosis

Background Given the need for quick and accurate dysphagia screening tools to optimize referral workflows and resource utilization in fast-paced multidisciplinary amyotrophic lateral sclerosis (ALS) clinics, we evaluated the discriminant ability of the 3 oz. water swallow test (WST) to detect aspiration in individuals with ALS. Methods A total of 212 paired 3 oz. WST (index test) and standardized videofluoroscopic swallow studies (reference test) were completed in individuals with a confirmed diagnosis of ALS. Blinded raters analyzed swallowing safety using the validated penetration-aspiration scale (PAS; non-aspirator: PAS < 6; aspirator: PAS >= 6). Receiver operating characteristic curve analysis, area under the curve (AUC), sensitivity, specificity, and positive and negative predictive values (PPV, NPV) were calculated. Key Results Index test: 78 (36.8%) WSTs were scored as a fail and 134 (63.2%) as a pass. Reference test: Aspiration was confirmed in 67 (31.6%) reference tests with 145 (68.4%) reference tests verified as having no aspiration. Sensitivity and specificity of the 3 oz. WST to detect radiographically confirmed aspiration was 55.2% and 71.7%, respectively (AUC: 0.635, PPV: 47.4%, NPV: 77.6%). Conclusions & Inferences In this dataset, the 3 oz. WST did not demonstrate adequate sensitivity or specificity to detect aspiration in people with ALS as a stand-alone dysphagia screening tool.