All version of the Brisbane EBLT have undergone psychometric analysis in three separate research studies. The tests have undergone analysis of:
Test Validity (diagnostic accuracy) – The ability of the Brisbane EBLT to identify acute post-stroke language deficits was assessed in a STARD compliant cross-sectional study at the Royal Brisbane and Women’s Hospital and Princess Alexandra Hospital in Brisbane, Australia.
Test validity was determined by comparing acute stroke patient performance on the Brisbane EBLT with their performance on a ‘gold-standard’ language battery to determine the sensitivity and specificity of the new Brisbane EBLT test. Overall, this study equated to 100 Brisbane EBLT test ratings.
Inter-Rater Reliability – The inter-rater reliability of the Brisbane EBLT was examined by comparing the Brisbane EBLT test scores of different speech pathologists when they scored the performance of the same stroke patients.
For this study, 15 speech pathologists of different experience levels were required to score the performance of the same 15 acute stroke patients. Comparison of these test scores determined the inter-rater reliability of Brisbane EBLT test items. Overall, this study equated to a total of 225 Brisbane EBLT test ratings.
Intra-Rater Reliability – The consistency of clinician Brisbane EBLT scores over time was examined by comparing the scores of 2 speech pathologists when they re-scored the same patient performance after a two week interval. Comparison of the test scores over time determined the intra-rater reliability of the Brisbane EBLT (total of 140 test ratings).
As part of the test development acute stroke patients and their family members were asked to provide feedback on the test items. In total, 74 patients and family members provided feedback on the test. This feedback was incorporated in the test development process.
To control for cultural bias within test items, the test was piloted with participants originating from the following English-speaking countries: Australia, New Zealand, England, Scotland, United States of America, Canada and South Africa. Any items with reported cultural bias were eliminated from the assessment.