Validation of the German Version of Functional Oral Intake Scale (FOIS-G) for Flexible Endoscopic Evaluation of Swallowing (FEES)

The Functional Oral Intake Scale (FOIS) is the most frequently used scale for the evaluation of functional oral intake by dysphagia patients. FOIS was validated using data from Videofluoroscopic Swallowing Study (VFSS). Until now, a validated German version of FOIS for Flexible Endoscopic Evaluation of Swallowing (FEES) is lacking. The aim of this study was a cross-cultural validation of the German version of FOIS (FOIS-G) for FEES. The translation of the original FOIS was carried out according to the Translation, Review, Adjudication, Pretesting, Documentation (TRAPD) translation methodology. For the validation process, six experienced language therapists (SLT) retrospectively analyzed charts of 93 stroke patients. Inclusion criteria were comprised of stroke, clinical examination by an SLT within 24 h of admission, and FEES within 72 h of admission. The validity was calculated by comparison with Modified Rankin Scale (MRS), Barthel Index (BI), the Penetration-Aspiration-Scale (PAS), and a water swallow test. Spearman rank correlation of all paired raters ranged from r(s) = 0.96 to r(s) = 0.99, and percentage agreement ranged from 81 to 94%. The overall agreement between all raters was calculated by Fleiss kappa (0.83) (s.e. 0.02). There is a significant correlation between the BI and the MRS with the FOIS-G (r(s) = 0.301, p = 0.003 for BI; r(s) = – 0.366, p < 0.001 for MRS), between the PAS and the FOIS-G (r(s) = − 0.758, p < 0.001), as well as between the 70 ml-water-test and the FOIS-G (r(s) = 0.470, p < 0.001). FOIS-G is a valid instrument for the evaluation of the functional oral intake of food and liquids in dysphagia patients.