Can EAT-10 Become EAT-5? Improving Measurement Efficiency of Dysphagia with Item Response Theory

Objectives: To assess: (1) the Eating Assessment Tool (EAT-10) with item response theory (IRT) to determine which individual items provide the most information, (2) the extent to which dysphagia is measured with subsets of items while maintaining precise score estimates, and (3) if 5-item scales have the differing discriminatory ability, as compared to the parent 10-item instrument. Methods: Prospectively collected data from 2,339 patients who completed the EAT-10 questionnaire during evaluation at a tertiary care otolaryngology clinic were utilized. IRT analyses provided discrimination and location parameters associated with individual questions. Residual item correlations were also assessed for redundant information. Based on these results, three 5-item subsets were further evaluated using item information function curves. Areas under receiver-operator characteristic curves (ROC-AUC) were also calculated to evaluate the discriminatory ability for dysphagia-related clinical diagnoses. Results: Item discrimination parameter estimates ranged from 1.71 to 5.46, with higher values indicating more information. Residual item correlations were determined within item pairs, and location parameters were calculated. Based on these data, in combination with clinical utility, three 5-item subsets were proposed and assessed. ROC-AUC analyses demonstrated no significant difference between the EAT-5-Alpha subset and the original 10-item instrument for discriminating dysphagia as a primary diagnosis (0.88, 0.88). The EAT-5-Clinical subset outperformed the original 10 instruments in ROC-AUC for aspiration. The EAT-5-Range subset was significantly associated with problems with thin liquids. Conclusions: IRT analyses distinguished three proposed 5-item subsets of the EAT-10 instrument, supporting shorter survey options, while still reflecting the impact of dysphagia without significant loss of discrimination.