Validation of the Italian Version of the Functional Oral Intake Scale (FOIS-It) Against Fiberoptic Endoscopic Evaluation of Swallowing and Nutritional Status

The Functional Oral Intake Scale (FOIS) is a reliable and valid tool to assess functional oral intake of food and liquids in patients with oropharyngeal dysphagia (OD). Its validity was established for stroke patients against Videofluoroscopic Swallowing Study in English and Chinese and against Fiberoptic Endoscopic Evaluation of Swallowing (FEES) in German. FOIS was cross-culturally validated into Italian (FOIS-It), but construct validity against instrumental assessment and nutritional status was not investigated. The study aims at contributing to the validation of the FOIS-It, by performing convergent and known-group validity against FEES and nutritional status in patients with OD of different etiologies. Overall, 220 adult patients with OD of etiological heterogeneity were recruited. FOIS-It score and Body Mass Index (BMI) were collected. FEES was performed to assess swallowing safety and efficiency based on the Penetration-Aspiration Scale (PAS) and the Yale Pharyngeal Residue Severity Rating Scale (YPRSRS). Moderate to weak associations with PAS (ρ = − .37, p < .01), YPRSRS in the pyriform sinuses (ρ = − .20, p < .01), and BMI (ρ = .24, p < .01) were detected with Spearman’s correlation. FOIS-It distribution was compared with the Mann–Whitney U and Kruskal–Wallis tests. Significantly lower FOIS-It scores were detected among patients with penetration/aspiration (PAS > 2) and penetration (PAS > 2 ≤ 5) for all consistencies (p < .01), aspiration (PAS > 5) of liquids and semisolids (p < .001), residue in the pyriform sinuses (YPRSRS > 3) with semisolids (p < .001) and solids (p = .02), and malnutrition (BMI ≤ 18.5; p = .019). FOIS-It appears as a valid tool to assess functional oral intake against FEES’ measures of swallowing safety and efficiency and nutritional status in patients with OD of etiological heterogeneity.