Content development of the VISION-Cog: a novel tool to assess cognitive impairment in visually impaired older adults in Singapore.

Objectives: Current cognitive screening and diagnostic instruments rely on visually dependent tasks and are, therefore, not suitable to assess cognitive impairment (CI) in visually impaired older adults. We describe the content development of the VISually Independent test battery Of NeuroCOGnition (VISION-Cog)-a new diagnostic tool to evaluate CI in visually impaired older Singaporean adults.

Design: The content development phase consisted of two iterative stages: a neuropsychological consultation and literature review (stage 1) and an expert-panel discussion (stage 2). In stage 1, we investigated currently available neuropsychological test batteries for CI to inform constructions of our preliminary test battery. We then deliberated this battery during a consensus meeting using the Modified Nominal Group technique (stage 2) to decide, via agreement of five experts, the content of a pilot neuropsychological battery for the visually impaired.

Setting: Singapore Eye Research Institute.

Participants: Stakeholders included researchers, psychologists, neurologists, neuro-ophthalmologists, geriatricians and psychiatrists.

Outcome Measure: pilot VISION-Cog.

Results: The two-stage process resulted in a pilot VISION-Cog consisting of nine vision-independent neuropsychological tests, including the modified spatial memory test, list learning, list recall and list recognition, adapted token test, semantic fluency, modified spatial analysis, verbal subtests of the frontal battery assessment, digit symbol, digit span forwards, and digit span backwards. These tests encompassed five cognitive domains-memory and learning, language, executive function, complex attention, and perceptual-motor abilities. The expert panel suggested improvements to the clarity of test instructions and culturally relevant test content. These suggestions were incorporated and iteratively pilot-tested by the study team until no further issues emerged.

Conclusions: We have developed a five-domain and nine-test VISION-Cog pilot instrument capable of replacing vision-dependent diagnostic batteries in aiding the clinician-based diagnosis of CI in visually impaired older adults. Subsequent phases will examine the VISION-Cog's feasibility, comprehensibility and acceptability; and evaluate its diagnostic performance.