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

Abstract

ObjectivesCurrent 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.DesignThe 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.SettingSingapore Eye Research Institute.ParticipantsStakeholders included researchers, psychologists, neurologists, neuro-ophthalmologists, geriatricians and psychiatrists.Outcome measurepilot VISION-Cog.ResultsThe 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.ConclusionsWe 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.

Feasibility, comprehensibility and acceptability of the VISION-Cog, a novel tool to assess cognitive impairment in visually impaired older adults: a cross-sectional pilot study in Singapore

“…It includes nine visually independent tests, namely 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. The test protocols have been described in detail previously, 13 and were formulated into a standardised test manual for the current study. The manual was then professionally translated into Mandarin by a certified translation centre using a forward-backward translation procedure to ensure the accuracy of instructions.…”

“…The test battery was considered feasible if the total duration did not exceed 90 min as determined by our expert panel in the previous phase. 13 …”

“…The purpose of this meeting was to seek experts’ opinions on the results obtained from the pilot study and revise the pilot VISION-Cog accordingly. Similar to the consensus meeting reported in a prior publication, 13 the expert panel consisted of one neuropsychologist, one neurologist, one neuro-ophthalmologist, one geriatrician and one psychiatrist/public health expert. The Informal Consensus Method (ICM), a qualitative technique of judgement aggregation based on majority voting, was used to conduct the meeting.…”

“…Similar to the previous consensus meeting, we used the content validity ratio (CVR) to evaluate consensus. 13 CVR has a range of −1 to 1 with a higher score demonstrating better agreement. To achieve consensus with five expert members, a minimum CVR of 0.99 was needed.…”

“…To address this important gap, our group has developed, using a multiphase, mixed-methods approach, a pilot version of the VIS ually I ndependent test battery O f N euro COG nition (VISION-Cog), a new diagnostic instrument to assess CI in older adults with VI (Phase 1). 13 Here, we report subsequent pilot studies to revise and fine-tune the VISION-Cog (Phase 2). This phase consisted of three stages: (1) A study in which the pilot VISION-Cog was first pilot-tested to examine its feasibility, comprehensibility and acceptability; (2) expert-panel discussion to seek agreement on a revised VISION-Cog version; and (3) a second study to ascertain improvement in feasibility, comprehensibility and acceptability of the revised VISION-Cog compared with the pilot version.…”