Validity, reliability and sensitivity of the NORLA-6: Naming and oral reading for language in aphasia 6-point scale
Purpose: Evaluation of the Naming and Oral Reading for Language in Aphasia 6-point scale (NORLA-6), a scoring system of oral reading and naming performance in aphasia.
Method: Data were drawn from 91 participants with non-fluent aphasia secondary to left-hemisphere stroke across four treatment studies. To assess validity, Spearman’s correlations were calculated between the NORLA-6 and the Gray Oral Reading Test-Fourth Edition (GORT-4) Accuracy score, GORT-4 Rate score and the Boston Naming Test (BNT). Inter-rater and test–retest reliability were evaluated using correlations. Sensitivity to change following oral reading intervention was analysed using Wilcoxon Signed Rank tests between pre- and post-treatment NORLA-6 scores.
Result: NORLA-6 performance was significantly correlated (p < 0.001) with all reference tests (GORT-4 Accuracy, rs=0.84; GORT-4 Rate, rs= 0.61; and BNT, rs= 0.92). Inter-rater (ICC ≥0.90) and test–retest (r > 0.92) reliability were both excellent. Sensitivity following oral reading intervention was demonstrated in both oral reading accuracy and rate (p < 0.004).
Conclusion: The NORLA-6 is a valid and reliable measure of oral reading and naming performance. It also demonstrates sensitivity to change in treatment-targeted behaviours. Therefore, the NORLA-6 scale may enhance outcome measurement in both clinical practice and aphasia research.