Development and diagnostic validation of the Brisbane Evidence-Based Language Test

Abstract

Purpose To describe the development and determine the diagnostic accuracy of the Brisbane Evidence-Based Language Test in detecting aphasia. Methods Consecutive acute stroke admissions (n = 100; mean = 66.49y) participated in a single (assessor) blinded cross-sectional study. Index assessment was the ∼45 min Brisbane Evidence-Based Language Test. The Brisbane Evidence-Based Language Test is further divided into four 15–25 min Short Tests: two Foundation Tests (severe impairment), Standard (moderate) and High Level Test (mild). Independent reference standard included the Language Screening Test, Aphasia Screening Test, Comprehensive Aphasia Test and/or Measure for Cognitive-Linguistic Abilities, treating team diagnosis and aphasia referral post-ward discharge. Results Brisbane Evidence-Based Language Test cut-off score of ≤157 demonstrated 80.8% (LR+ =10.9) sensitivity and 92.6% (LR− =0.21) specificity. All Short Tests reported specificities of ≥92.6%. Foundation Tests I (cut-off ≤61) and II (cut-off ≤51) reported lower sensitivity (≥57.5%) given their focus on severe conditions. The Standard (cut-off ≤90) and High Level Test (cut-off ≤78) reported sensitivities of ≥72.6%. Conclusion The Brisbane Evidence-Based Language Test is a sensitive assessment of aphasia. Diagnostically, the High Level Test recorded the highest psychometric capabilities of the Short Tests, equivalent to the full Brisbane Evidence-Based Language Test. The test is available for download from brisbanetest.org. Implications for rehabilitation Aphasia is a debilitating condition and accurate identification of language disorders is important in healthcare. Language assessment is complex and the accuracy of assessment procedures is dependent upon a variety of factors. The Brisbane Evidence-Based Language Test is a new evidence-based language test specifically designed to adapt to varying patient need, clinical contexts and co-occurring conditions. In this cross-sectional validation study, the Brisbane Evidence-Based Language Test was found to be a sensitive measure for identifying aphasia in stroke.