Reliability of repeated cognitive testing in healthy Indigenous Australian adolescents

Abstract

Serial assessment is required in situations where decline or recovery of function is anticipated. Serial assessment of cognition in Indigenous populations, however, can be problematic due to a lack of culturally appropriate assessments with psychometric properties suitable for repeated administration. This study assessed a non-verbal, culturally neutral, computerised cognitive test battery for its test–retest reliability and any practice effects in a sample of 40 healthy Indigenous adolescents (mean age = 15.25 years). No practice effects and adequate retest reliabilities were recorded for both accuracy and speed on tests of psychomotor function, visual attention and working memory (i.e. card tasks). A lack of practice effects and adequate reliabilities were also observed for accuracy (but not speed) on the more complex learning and memory tasks (i.e. non-card tasks). Interestingly, this outcome contrasts with those of similar studies in which the performance of non-Indigenous people on the same tasks showed speed to be a more reliable measure than accuracy, and this may reflect different perceptions of time between these groups. Among Indigenous adolescents, this study demonstrates acceptable reliability and stability of the selected cognitive assessment process, providing validity for its use as a research and screening tool in this population.