<![CDATA[Reaction-time assessment can be challenging in adolescents with Down syndrome because testing procedures may require sustained attention, comprehension of instructions, and coordinated sensory-motor responses. The hand-touch reaction test is a low-cost field test involving an auditory color cue followed by movement to and hand contact with a corresponding-colored cone. Although the test has been used in typically developing school populations, evidence concerning its reliability in adolescents with Down syndrome is limited. This study examined the intra-day reliability of the hand-touch reaction test in adolescents with Down syndrome. Thirty adolescents with Down syndrome aged 14–18 years participated in four testing sessions conducted on the same day. In each session, participants completed four trials with randomized left/right color cues; the fastest trial was retained as the session score. Reliability across the four session scores was examined using a two-way mixed-effects intraclass correlation coefficient (ICC) with an absolute-agreement definition and 95% confidence intervals. Analyses were conducted in IBM SPSS Statistics version 25. Mean response times across the four sessions were 3.690 ± 0.571 s, 3.747 ± 0.527 s, 3.659 ± 0.618 s, and 3.659 ± 0.451 s, respectively. The single-measure ICC was 0.849 (95% CI 0.757–0.916), whereas the average-measure ICC was 0.957 (95% CI 0.926–0.978). These estimates indicate high consistency across repeated same-day administrations. The hand-touch reaction test demonstrated high intra-day reliability in this sample of adolescents with Down syndrome. The findings support its use as a practical field-based measure of the test performance captured by this protocol. However, because all sessions occurred on the same day and timing relied on a manual stopwatch, further studies should examine inter-day reliability and measurement error before the test is used for clinical decision-making or individual monitoring.]]>
