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

Abstract

Objective: 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. Method: 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 ) screening tools. All tools were compared to the MMSE and the influence of demographic variables on the performance on these tools was considered. Results: 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<.001) with the alternate item favouring better performance. Based on the MMSE cutoff score of < 23, the prevalence of cognitive impairment was 16.9%; the prevalence yielded by the remaining tools ranged from 10.5% using the DECO to 46% as determined by the presence of a SMC. Using the MMSE as the reference standard for the presence of cognitive impairment, the SIS, SMC, SMRS and DECO had sensitivities of 82.3%, 54.6%, 17.0% and 37.5%, and specificities of 71.3%, 57.6%, 87.4% and 96.7% respectively. Age and race influenced performance on the MMSE, SIS and SMRS. Conclusion: Different types of cognitive screening tools yielded varying sensitivities and specificities for identifying cognitive impairment when compared to the MMSE. The influence of race, age and education on test performance highlights the need for suitable, culture-fair screening tools. Locally, the alternate item for attention/concentration should be preferred. However, the serious consequences of population ageing do not appear to be planned for as evidenced by the lack of a national dementia care policy. There is a lack of recent data on morbidity as well as a paucity of research particularly in the areas of cognitive, mental and physical functioning of the elderly. 3 Dementia, a condition largely affecting the aged, requires specialised services, few of which exist either in the public or private health sector in South Africa. The projected increase in the prevalence of Afr J Psychiatry 2013;16:445-455 ORIGINAL

The Sensitivity and Specificity of Subjective Memory Complaints and the Subjective Memory Rating Scale, Deterioration Cognitive Observee, Mini-Mental State Examination, Six-Item Screener and Clock Drawing Test in Dementia Screening

“…While all 140 of the sample had MMSE, SIS and SMCC scores, SMRS scores were only available for those who reported the presence of subjective impairment (n = 69), and DECO scores were only available for those participants who had contactable informants (n = 34) [40] . The prevalence data for dementia and MCI are reported fully in a separate paper [41] .…”

“…For those participants who reported the presence of a subjective memory complaint, the SMRS [38] was also administered. If an informant was available, the informant DECO scale [39] was also administered (n = 76), with the results of this stage being reported separately elsewhere [40] .…”

Factors Associated with the Prevalence of Cognitive Impairment in a Rural Elderly Cameroonian Population: A Community-Based Study in Sub-Saharan Africa

“…These discrepancies could have arisen because we used education-specific cut-off values which improved the sensitivity and specificity of our tool and the variations in sociodemographic characteristics across the different study settings. In settings where the proportion of individuals with no formal education is high, it is recommended to adjust cut-offs to educational level, cultural, or age-specific factors which could influence the overall score [23, 24]. The norms developed by Crum et al [25] constitute the largest database in use with a recommended cut-off score of 19 for those with 0–4 years of education, 23 for those with 5–8 years of education, 27 for those with 9–12 years of education, and 29 for those with college education.…”

The Evaluation of Mental Status of Elderly Patients Presenting to Emergency Services and the Comparison Between the Last Diagnosis and Their Complaints

“…In a study by Christopher 16 , comparing the AD8 and SQST with the MMSE, it was determined that the sensitivity of the SQST was 74% and specificity was 77%. In another study, Ramlall et al reported that using the MMSE as the reference standard for the presence of cognitive impairment, the SQST had a sensitivity of 82.3% and specificity of 71.3% 17 . In this study, the MMSE identified 51 while the SQST identified twice the number (114) of participants with a possible cognitive impairment.…”