Reliability and Optimal Cut-Off Points of the Test for Upper Limb Apraxia (TULIA) for Spanish Speaking Post-Stroke Patients

Abstract

Objective: To evaluate the reliability, identify the optimal cut-off points, and determine the diagnostic accuracy of the TULIA Apraxia test in a sample of Spanish-speaking post-stroke patients. Design: Cross-sectional. Setting: Public primary care. Participants: 201 post-stroke patients. Main Measures: Reliability was assessed using Cronbach’s alpha. Cut-off points were identified for each TULIA Apraxia sub-test and stratified for age (≤65 years, > 65 years) using ROC curve analysis, area under the curve, and Youden index. Diagnostic accuracy was evaluated using sensitivity, specificity, and predictive values. Results: Cronbach’s alpha of the sub-tests varied from 0.716 (95% CI 0.653–0.772) for pantomime intransitive to 0.824 (95% CI 0.784–0.858) for imitation non-symbolic. Cut-off points ranged from ≤25 to ≤35 points. For individuals aged ≤65 years, the cut-offs that best balanced sensitivity and specificity were ≤25 points for detecting alterations in imitation transitive and ≤33 points for pantomime non-symbolic. For individuals over 65 years, the imitation transitive cut-off (≤26 points) presented the most adjusted balance. The minimum positive predictive value was 0.667 (95% CI 0.542–0.777), indicating that the TULIA Apraxia tests correctly classified more than 67% of patients with apraxia. The minimum negative predictive value was 0.763 (95% CI 0.644–0.859), showing that the test accurately identified more than 76% of patients without apraxia. Conclusions: The TULIA Apraxia test is reliable in Spanish-speaking post-stroke patients. Optimal cut-off points, along with their respective sensitivity and specificity values, exhibit adequate test accuracy. Predictive values indicate that the test correctly identifies individuals with and without apraxia.