Validity and reliability of the Thai Shortened Token Test

Abstract

Background: The Token Test (TT) helps evaluate language comprehension in individuals with aphasia. This test can detect comprehension difficulties, even in mild aphasia cases. In Thailand, the other language tests for aphasia focused primarily on multiple aspects of language, which took a long time to evaluate. The Shortened TT, which has fewer commands, has been chosen to be translated for this study. Previously, the Shortened TT was translated into Thai using only forward translation and had not yet been evaluated for its psychometric properties. Thus, this study focuses on translating the Shortened TT into Thai using a forward and backward translation process and determining its validity and reliability. Objective: To translate, validate, and determine the reliability of the Thai Shortened TT. Materials and methods: The Shortened TT was translated using forward and backward translation. Following the completion of the translation process, five expert speech-language pathologists (SLPs) evaluated its content validity using the Content Validity Index (CVI), the Content Validity Index for Items (I-CVI), and the Content Validity Index for Scales (S-CVI). Then, it was administered to 12 normal participants and 12 aphasia participants to determine the test-retest, intra-, and inter-rater reliability using the Intraclass Correlation Coefficient (ICC). Results: The Thai Shortened TT’s content validity was satisfied at CVI=0.920, I-CVI=0.800-1, and S-CVI=0.983. The test-retest, intra-, and inter-rater reliability were excellent. In the normal group, they were 0.943, 0.985, and 0.974, respectively; in the aphasia group, they were 0.985, 0.999, and 0.999, respectively. Conclusion: This study indicated that the Thai Shortened TT can be utilized and is suitable for clinical evaluation regarding its content validity and reliability.