Montreal Cognitive Assessment: Exploring the impact of demographic variables, internal consistency reliability and discriminant validity in a South African sample

Elisabeth Kirkbride,Mlinganisi Sibandze,Aline Ferreira-Correia

doi:10.4102/ajopa.v4i0.73

Abstract

The Montreal Cognitive Assessment (MoCA) is widely used to screen for cognitive impairment and has shown a good capacity to identify cognitive impairment. However, its psychometric properties have not been sufficiently studied in the South African context. Therefore, this study aimed to investigate (1) the influence of demographic variables (age, years of education, and gender) on total MoCA scores; (2) the internal consistency reliability of the test and (3) the discriminant validity of the total MoCA score. This study analysed secondary quantitative data, utilising a cross-sectional, between-subjects design. All participants completed the English MoCA version 8.1. The control sample (n = 89) included healthy South African adults who speak English as a second or third language and who have been educated in public schools. The clinical sample (n = 83) included patients with human immunodeficiency virus (HIV) and a comorbid disorder, either psychiatric (n = 70) or neurocognitive (n = 13). Total MoCA scores were significantly correlated with years of education (p 0.001) and age (p = 0.007) but not gender. Cronbach’s alpha was 0.64 revealing moderate internal consistency. The total MoCA score was not a significant predictor of diagnostic status, indicating poor discriminant validity of the MoCA in this sample. The MoCA appears not to be a useful screening or diagnostic tool in samples with similar characteristics.

Highlights

The Montreal Cognitive Assessment (MoCA) is a brief screening tool developed to detect mild cognitive impairment (MCI), which can be a precursor to dementia (Nasreddine et al, 2005)
The final clinical sample included participants who had a dual clinical diagnosis, classified into two groups: (1) participants with human immunodeficiency virus (HIV) and comorbid psychiatric disorder, consisting of mood disorder, psychosis, or mood and psychosis disorders and (2) HIV participants with comorbid NCD, including HIVassociated dementia (HAD) and mild neurocognitive disorder (MND), with or without an additional psychiatric disorder. The rationale behind this classification is to determine whether the level of severity of cognitive impairment, where NCD is more severe than psychiatric disorder, influences MoCA performance and/or the ability of MoCA to discriminate between these two clinical groups
The control group was not well matched to the clinical groups in terms of gender; the proportion of males in http://www.ajopa.org the control group (n = 41) was significantly higher than in the MP (n = 17) and NCD (n = 2) groups, c2(2, n = 172) = 10.5, p = 0.005. These results indicate that diagnostic groups were not well matched in terms of age, years of education, and gender

Summary

Introduction

The Montreal Cognitive Assessment (MoCA) is a brief screening tool developed to detect mild cognitive impairment (MCI), which can be a precursor to dementia (Nasreddine et al, 2005). Our study aims to address some of these gaps and contribute to the limited body of literature on the MoCA in South Africa by exploring the influence of age, years of education and gender, on total MoCA score, and internal consistency, in a sample of South African adults that speak English as a second or third language and have been educated in public schools It investigates the MoCA’s discriminant validity in terms of its capacity to identify cognitive impairment in a sample of patients with dual diagnosis, http://www.ajopa.org

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