Reliability of the Japanese Version of the Kit for Assessment of Time Processing Ability (KaTid)-Child in Typically...

Children with developmental disabilities often experience difficulties in time management, which negatively affect their daily functioning and social adjustment. The Kit for Assessment of Time Processing Ability (KaTid) is a validated Swedish instrument for assessing time management skills. However, its use in Japan remains limited, and a culturally adapted version has not yet been validated.

This study aimed to validate the Japanese version of the KaTid-Child (KaTid-C-J) by examining its test-retest reliability, inter-rater reliability, and comparability of Time Processing Ability (TPA) scores with the developmental age bands of the original Swedish KaTid-Child.

Twelve typically developing children aged 5-10 years were recruited through snowball sampling. The KaTid-C-J was administered twice by the same examiner with an interval of 30-60 minutes to assess test-retest reliability. Video recordings were independently scored by another rater to assess inter-rater reliability. Spearman's correlation, Bland-Altman plots, Cohen's kappa, and intraclass correlation coefficients (ICCs) were used to examine reliability. Bootstrapping was performed to estimate 95% confidence intervals (CIs). Comparisons between the Japanese and Swedish versions were made using chi-squared tests.

Test-retest reliability showed moderate-to-strong correlations (Spearman's ρ = 0.531-0.872) across four domains of time processing (TP, TO/TC, TO/OT, TM), with no systematic or random errors. Inter-rater reliability was perfect, with both kappa and ICC values of 1.00. The Japanese and Swedish versions demonstrated high concordance for children aged 8-10 years; however, children aged 5-7 years showed slightly higher ability scores in the Japanese version, possibly due to linguistic and cultural differences in month-naming conventions.

The Japanese version of the KaTid-Child demonstrated high test-retest and inter-rater reliability, supporting its potential as a reliable tool for assessing time processing ability in typically developing Japanese children. Further studies with larger and more diverse samples are needed to confirm its validity and cross-cultural applicability.