PUB - Publikationen an der Universität Bielefeld

Objectives: As the prevalence of age-related disorders-including dementia-continues to rise among individuals with intellectual disabilities, there is an increasing need for psychometrically sound assessment instruments. Methods: Individuals with intellectual disabilities (n = 86), both with (n = 13) and without (n = 73) dementia, were assessed using the Dementia Test for People with Intellectual Disability (DTIM) at three distinct time points (T1-T3) in a blinded setting. Results: Participants with dementia demonstrated significantly lower DTIM total scores at T1 (38.54 vs. 49.42; p = 0.02) compared to those without dementia. We observed a mean decline of 3 points from T1 to T3 in the dementia group, which was not statistically significant. For the established cut-score, receiver operating characteristic analysis yielded an area under the curve of 0.645, with a sensitivity of 0.54, a specificity of 0.71, and a Cohen's kappa of 0.17. Convergent validity between the DTIM total score and the Neuropsychological Test Battery was strong, while no significant correlation was found with the Aberrant Behaviour Checklist. Conclusions: These results suggest that the DTIM may be a useful tool for assessing cognitive decline in individuals with intellectual disabilities. To strengthen the evidence, future studies should include larger and more balanced samples to provide more robust and generalizable findings.