Alzheimer’s Quick Test cognitive screening criteria for West African speakers of Krio

Abstract

To obtain normative data for Alzheimer's Quick Test (AQT) measures of perceptual and cognitive speed from West African speakers of Krio. Normal adults, who were functionally independent, from Sierra Leone (n = 164) aged 25-79 years. Perceptual and cognitive speed were measured with AQT single- and dual-dimension colour-number (C-N) and colour-animal (C-A) naming tasks. Tests were administered individually in the participants' communities. Men and women performed similarly (P>0.05), whereas literate speakers used significantly less time than preliterate peers (P<0.01). Correlations between age and colour naming were low (P<0.01) and speed decreased by <0.1 s per year. Dual-dimension naming remained stable across ages. Correlations with years of education were low for dual-dimension naming (P<0.01) and speed increased approximately 0.4 s per added year. Correlations between age and education and AQT naming were non-significant for literate participants. Criterion time cut-offs (seconds) for screening were developed for preliterate and literate speakers of Krio for typical (<+1 SD), slower-than-typical (between +1 and +2 SD) and atypical (>+2 SD) performance. AQT C-N and C-A naming are time efficient (3-5 min each), objective and reliable and can be administered in Krio to West African adults in Africa, Europe or North America to screen for cognitive impairments and facilitate referral for medical workup.