2 The Vietnamese Montreal Cognitive Assessment: An Evaluation of Construct Validity and Recommended Cut-off for Cognitive Impairment after TBI

Abstract

Objective:Cognitive screening tools such as the Montreal Cognitive Assessment (MoCA) play an essential role in the clinical evaluation of neuropsychological functions. Despite the extensive investigations of the MoCA in English speaking countries as well as emerging adaptation work in a few Asian cultures, evidence base for the utility of the Vietnamese MoCA (MoCA-V) is lacking. This has posed a huge challenge for current and future clinical practice in Vietnam, as the country continues to assume a large burden of brain-related disorders. This study examined the construct validity of the MoCA-V and identified a cut-off score for the determination of cognitive impairment in a prevalent neurological condition in Vietnam - traumatic brain injury (TBI).Participants and Methods:Participants included 129 neurologically healthy individuals and 80 patients with moderate-to-severe TBI. All participants completed the MoCA-V, along with other common neurocognitive measures such as the Trail Making Test (TMT) Parts A and B, Vietnamese Verbal Fluency Test, and Digit Span.Results:Pearson’s correlations revealed significant, moderate correlations between performance on the MoCA-V subdomains and more comprehensive cognitive measures. Performance on the MoCA-V Attention domain was correlated with both Digit Span Forward, r(110) = .453, p < .001] and Digit Span Backward, r(110) = .303, p = .001; performance on the MoCA Language domain was correlated with the Vietnamese Verbal Fluency Test, r(107) = .334, p < .001; and performance on the MoCA Executive Function domain was correlated with the TMT-B, r(108) = -.479, p = .022. Performance on the MoCA-V was also associated with age, r(127) = -.659, p < .001, and education, r(127) = .769, p < .001, consistent with the general effects of age and education in cognitive abilities. Finally, a cut-off score of 22.5 was identified for the detection of cognitive impairment in Vietnamese people with TBI (AUC = 0.811; 95% CI = .75-.87, p < .001).Conclusions:This study provides the first evidence for the construct validity and clinical utility of the MoCA-V. Future research is necessary to cross-validate study findings among other clinical populations. Lessons learned from neuropsychological test translation and adaptation process will be discussed, particularly in the development of the administration materials and test instructions (e.g., considerations for individuals with limited formal education, influences of colonialism in the development of test stimuli).