Cognitive Testing in Scottish Memory Clinics: Comparison of the RUDAS and the MoCA

BACKGROUND With the global prevalence of dementia projected to rise in the context of demographic change, there is increasing demand for appropriate screening tools to detect dementia in diverse populations. However, a significant challenge to disease detection is the influence of culture on cognitive assessment. The Rowland Universal Dementia Assessment Scale (RUDAS) was specifically developed to minimise the effects of culture on test performance. It has been validated cross-culturally but has never been evaluated in the UK. The aim of this study was to compare performance on the RUDAS with the Montreal Cognitive Assessment (MoCA), a commonly used screening tool, to determine concurrent validity in a Scottish sample, and to establish both the reliability and influence of demographic and health-related variables on test performance. METHODS A cross-sectional study was conducted whereby performance on the RUDAS and MoCA was compared for a sample of 47 older adults (aged 65+ years). Participants were recruited from a clinical population of patients presenting to NHS memory clinics for evaluation of cognitive decline. The influence of demographic and health-related variables (age, sex, years of education, depression, vascular risk factors, and diabetes) were measured using multiple linear regression, and inter-rater reliabilities were determined for both tests using intraclass correlation coefficients (ICC). CONCLUSION • The RUDAS demonstrated moderate concurrent validity with the MoCA and comparatively excellent inter-rater reliability. This replicates the moderate correlations between the RUDAS and MoCA reported in other studies and demonstrates adequate concurrent validity for the RUDAS in a UK population. • Demographic and health-related variables did not significantly influence test scores and accounted for relatively little variance in both measures. This suggests that the RUDAS and MoCA were similarly insusceptible to a range of variables known to influence cognition. • There was double the number of cases scoring in the impaired range on the MoCA compared to the RUDAS. This likely reflects the RUDAS’ higher threshold (i.e., lower cut-off score) and the MoCA’s sensitivity, but suggests potential problems for the MoCA’s specificity. IMPLICATIONS These results provide encouraging preliminary evidence for the RUDAS’ clinical utility in the UK, but further research into diagnostic accuracy and discriminant validity of the RUDAS is required with culturally and ethnically diverse UK samples to recommend its use cross-culturally