Screening for Acquired Cognitive Impairment and Dementia in Deaf Users of German Sign Language: The Cognition Test...

There is a lack of appropriate cognitive assessment tools to detect acquired cognitive impairment or dementia in deaf sign language users in Germany. To address this, the British Sign Language Cognitive Screening Test (BSL-CST) was culturally and linguistically adapted to German Sign Language and the German Deaf community, to be administered using a standardized video format.

A comprehensive 15-step cultural test adaptation paradigm was applied, involving focus groups, clinical experts and members of the Deaf community. Norming data were collected for the newly adapted Cognition Test German Sign Language (KoDGS), resulting in a cognitively healthy sample (n = 86; age 50-92) and a sample of individuals with neurological history (n = 13).

The KoDGS demonstrated robust test validity through convergent measures, sensitivity to age and education, and applicability across the heterogeneous German deaf population. Percentiles for the cognitively healthy sample were reported, and receiver operating characteristic curve analysis revealed high clinical reliability in distinguishing between the groups.

This study breaks new ground in the cross-linguistic and cross-cultural adaptation of dementia assessments in signed languages. The statistical reliability and clinical applicability of the test, along with the presented adaptation paradigm, provide a foundation for future adaptations of other cognitive assessments. As the first screening tool for cognitive impairment and dementia in deaf sign language users in Germany, the KoDGS has the potential to improve how deaf individuals are cognitively assessed for dementia.