RESUMO
BACKGROUND: Early diagnosis of cognitive impairment allows timely intervention with pharmacological and non-pharmacological measures. However, current cognitive evaluation tools do not cater for multilingual populations. OBJECTIVE: To develop and validate a visual-based cognitive evaluation tool, the Visual Cognitive Assessment Test (VCAT), which can be administered to multilingual populations without the need for translation or adaptation. METHOD: We designed a battery of tests to evaluate the domains of memory, executive function, visuospatial function, language and attention. Pilot testing of individual test items, followed by test refinement and development of a field version was performed. We subsequently validated VCAT for the diagnosis of mild cognitive impairment (MCI) and mild Alzheimer's disease (AD). Diagnostic performance was assessed by the area under the curve (AUC), sensitivity (Se) and specificity (Sp). RESULTS: VCAT was validated in a sample of 206 participants. The sample comprised 53.9% males; mean age (SD) was 67.8 (8.86) years; mean years of education was 10.5(6.0). AUC of VCAT for detection of cognitive impairment was found to be 93.3 (95% CI 90.1 to 96.4). Also, the Se and Sp of VCAT for the diagnosis of cognitive impairment (MCI and mild AD) were 85.6% and 81.1%, respectively. VCAT's diagnostic Se and Sp comparable to those of the Montreal Cognitive Assessment in the same cohort. Mean time-to-complete VCAT was 15.7 ± 7.3 min. CONCLUSIONS: The VCAT has good Se and Sp for the diagnosis of MCI and mild AD. The visual-based test paradigm allows easy application to multilingual populations without the need for translation or adaptation.
