Screening a heterogeneous elderly South African population for cognitive impairment: the utility and performance of the Mini- Mental State Examination, Six Item Screener, Subjective Memory Rating Scale and Deterioration Cognitive Observee

The aim of this study was to report on the prevalence of cognitive impairment, and to assess the performance and utility of subjective, objective and informant screening tools in a heterogeneous community sample. A sample of 302 elderly participants (>60 years) living in residential homes in a large city in South Africa were screened for the presence of cognitive impairment using objective (Mini-Mental State Examination [MMSE] and Six Item Screener-[SIS]), subjective (Subjective Memory Complaint [SMC]and Subjective Memory Rating Scale [SMRS]) and informant (Deterioration Cognitive Observee [DECO]) screening tools. All tools were compared to the MMSE and the influence of demographic variables on the performance on these tools was considered. Significantly lower MMSE scores were found in participants aged 80-89 years (p=.023) and those who had 8-11 years of education (p=.002). For every one additional year of education, participants were 0.71 times less likely to screen positive on the MMSE. Differential item functioning on various components of the MMSE was demonstrated due to the effects of education, race and gender. There was significant differential performance between the recommended and alternate attention/concentration items (p