Detecting Cognitive Impairment and Dementia in Deaf People: The British Sign Language Cognitive Screening Test.

To provide accurate diagnostic screening of deaf people who use signed communication, cognitive tests must be devised in signed languages with normative deaf samples. This article describes the development of the first screening test for the detection of cognitive impairment and dementia in deaf signers. The British Sign Language Cognitive Screening Test uses standardized video administration to screen cognition using signed, rather than spoken or written, instructions and a large norm-referenced sample of 226 deaf older people. Percentiles are provided for clinical comparison. The tests showed good reliability, content validity, and correlation with age, intellectual ability, and education. Clinical discrimination was shown between the normative sample and 14 deaf patients with dementia. This innovative testing approach transforms the ability to detect dementia in deaf people, avoids the difficulties of using an interpreter, and enables culturally and linguistically sensitive assessment of deaf signers, with international potential for adaptation into other signed languages.