The impact of illiteracy on the assessment of cognition and dementia: a critical issue in the developing countries

Diagnostic accuracy of cognitive screening tools validated for older adults in Iran: a systematic review and meta-analysis

BACKGROUND

This systematic review aims to comprehensively assess the diagnostic accuracy of cognitive screening tools validated for older adults in Iran, providing evidence-based recommendations for clinicians and researchers.

METHODS

A comprehensive search in March 2023 across Web of Science, PubMed, Scopus, ScienceDirect, SID, IranMedex, and IranDoc, enhanced by hand-searching references and Google Scholar, identified cross-sectional studies on cognitive screening in Iranian seniors. We assessed diagnostic accuracy, cognitive domains, and test strengths and weaknesses. A bivariate random-effects meta-analysis provided summary estimates and 95% confidence intervals, illustrated in forest plots.

RESULTS

Our review, derived from an initial screening of 38 articles, focused on 17 studies involving 14 cognitive screening tools and participant counts from 60 to 350, mostly from specialized clinics. The MMSE was the only tool examined in at least three studies, prompting a meta-analysis revealing its sensitivity at 0.89 and specificity at 0.77 for dementia detection, albeit amidst significant heterogeneity (I^2 > 80%). ACE-III demonstrated the highest diagnostic accuracy for MCI and dementia, while MoCA's performance was deemed adequate for MCI and excellent for dementia. High bias risk in studies limits interpretation.

CONCLUSION

This review identifies key cognitive tools for dementia and MCI in Iranian older adults, tailored to educational levels for use in primary and specialized care. It emphasizes the need for further validation to enhance diagnostic precision across diverse settings, within a concise framework prioritizing brevity and accuracy for clinical applicability.

Algorithms for Operationalizing Mild Cognitive Impairment Using the Spanish-Language NIH Toolbox Cognition Battery

OBJECTIVE

Neuropsychologists would benefit from flexible methods for operationalizing psychometric cognitive impairment in Spanish-speaking examinees that vary in association with intelligence, education, and sociocultural characteristics. The current study combined low and high score base rates (BRs) for the Spanish-language NIH Toolbox Cognition Battery (NIHTB-CB) to identify score combinations that are uncommon within different stratifications of the normative sample and may indicate cognitive impairment.

METHOD

The Spanish-language NIHTB-CB normative sample included 250 healthy Latinx adults with complete data on two crystallized and five fluid cognitive tests (M = 38.8 ± 13.7 years old, 72.0% women). Test performances were converted into age-adjusted and demographically adjusted normed scores, adjusting for age, gender, and education. The frequencies at which participants obtained one or more low scores or few to no high scores on fluid cognitive tests were combined into algorithms that occurred at BRs approximately 1 SD (~16%) or 1.5 SDs (~7%) below the mean.

RESULTS

Algorithms are provided for age-adjusted and demographically adjusted scores, with BRs stratified by crystallized ability, education, and sociocultural characteristics. Using demographically adjusted norms, the BR of obtaining any one of the following, 5 scores <50th, 4+ scores ≤25th, 3+ scores ≤16th, or 2+ scores ≤9th percentile, approximates 1 SD below the mean in participants born (BR = 16.2%) or educated abroad (BR = 18.6%), who are monolingual Spanish speakers (BR = 16.4%) or who reside in low-income households (BR = 13.6%).

CONCLUSIONS

These algorithms offer a flexible approach to operationalizing psychometric cognitive impairment, through which different definitions can be applied to different examinees based on varying crystallized ability, education, and sociocultural characteristics.

A Multivariate Interpretation of the Spanish-Language NIH Toolbox Cognition Battery: The Normal Frequency of Low Scores

OBJECTIVE

The current study involved the preparation of multivariate base rates for the Spanish-language NIH Toolbox Cognition Battery (NIHTB-CB) based on the U.S. normative sample, quantifying the normal frequency of low scores among healthy adults.

METHOD

Participants included 250 healthy Latinx adults (M = 38.8 ± 13.7 years old, range: 19-80; 72.0% women; education: M = 11.5 ± 3.9 years) who completed the full Spanish-language NIHTB-CB, including two tests of crystallized cognition and five tests of fluid cognition. Multivariate base rates quantified the frequency at which participants obtained 1 or more fluid scores ≤25th, ≤16th, ≤9th, ≤5th, and ≤2nd percentile, per age-adjusted or demographically adjusted (age, gender, education) normed scores.

RESULTS

A substantial minority of participants had 1 or more low scores (e.g., 40.4% had 1 or more age-adjusted score ≤16th percentile). The frequencies of low scores increased with fewer years of education and lower crystallized cognitive ability. Higher frequencies of low scores were observed among participants who were born and educated abroad, versus within the USA; monolingual Spanish speakers, versus bilingual Spanish/English speakers; and from households below the national median income, versus households above the national median.

CONCLUSION

Low scores were common and related to crystallized ability, education, and sociocultural variables. Although using demographically adjusted scores reduced group differences related to sociocultural variables, group differences were not eliminated, indicating that age, gender, and education score adjustments do not fully explain the associations between sociocultural variables and test performances. These stratified base rates may be useful when working with Spanish-speaking patients with diverse sociocultural characteristics.

A model of cognitive evaluation battery for diagnosis of mild cognitive impairment and dementia in educated and illiterate Egyptian elderly people

Background

The high illiteracy rates in the North African and Middle Eastern region make direct cognitive testing challenging. Validated instruments for dementia in Arabic language are lacking specially those targeting low-educated subjects.

Objectives

The aim of this study was to develop a cognitive evaluation battery suitable for both educated and illiterate Egyptian elderly people.

Design

A cross-sectional study was conducted. Setting: Ain-Shams University geriatric and ophthalmology wards, geriatrics outpatient clinic, and geriatric clubs. Participants: 159 male and female participants aged ≥ 60 years were recruited.

Measurements

Cut-off points were determined according to DSM-IV criteria for dementia and MMSE scores which divided the participants into 3 quadrants as normal, having mild cognitive impairment and having dementia then application of the new battery test was done.

Results

Test re-test reliability ranged from adequate to high in most of its tests with r ≥ 0.7. There was a statistical significance between all battery tests when divided into normal and dementia according to DSM IV criteria except in digit span forward length, digit span backward length, stimulus cue of confrontation naming and judgment. Means and standard deviations were calculated for each battery subset, for the whole sample, for low-educated group and group with > 9 years education according to three quadrants of MMSE.

Conclusion

A new valid and reliable neurocognitive evaluation battery that can differentiate between normal, mild cognitive impairment, and dementia in both educated and illiterate subjects under the name of Ain Shams Cognitive Assessment (ASCA) scale is now available.

Validation of the RUDAS for the Identification of Dementia in Illiterate and Low-Educated Older Adults in Lima, Peru

Objectives: To evaluate the performance of the Peruvian version of the Rowland Universal Dementia Assessment Scale (RUDAS-PE) in discriminating between controls and patients with mild cognitive impairment (MCI) and dementia in an illiterate population with low-levels of education. Methods: We compared the cognitive performance of 187 elderly subjects who were illiterate (controls n = 60; MCI n = 64; dementia n = 63). Neuropsychological measures included the RUDAS-PE, Mini-Mental State Examination (MMSE), INECO Frontal Screening (IFS), and Pfeffer Functional Activities Questionnaire (PFAQ). The results were compared to a neuropsychological evaluation (gold standard), including use of Clinical Dementia Rating (CDR) scores. Results: We found a Cronbach's alpha was 0.65; Spearman's correlation coefficient was 0.79 (p < 0.01). The area under the receiver operating characteristics curve for the RUDAS to discriminate dementia from MCI was 98.0% with an optimal cut-off <19 (sensitivity 95%, specificity 97%); whereas, to differentiate MCI and controls was 98.0% with an optimal cut-off <23 (sensitivity 89%, specificity 93%). Conclusions: Based on its excellent psychometric properties, we find the RUDAS-PE suitable to aid in the opportune detection of dementia in a geriatric illiterate population with low-levels of education.

Screening for Cognitive Impairment in Geriatrics

There are many instruments for screening cognitive impairment. The common tools for screening cognitive impairment are categorized into 4 groups (very brief, brief, self-administered, and test batteries) in geriatrics. There are some tests used for specific tests of 6 cognitive domains (learning and memory, language, executive function, complex attention, and social cognition) by following the DSM-V criteria. Different settings, stages, conditions, and specific people need some specific tools for screening cognitive impairment. It must be noted that there is some harm in screening for cognitive impairment in geriatrics.

Associations between ApoE gene and psychological consequences post stroke in a Bahraini cohort

BACKGROUND

The contribution of genetic factors such as the presence of ApoE allele e4 and its association with psychological consequences post stroke remains unknown within Middle-Eastern regions. This study examined the association of ApoE genotype with cognitive impairment and mood in stroke patients and compare with healthy older adults in Bahrain.

METHOD

A prospective sample of n = 62 stroke patients (case group) and n = 53 healthy ageing individuals (control group) were eligible to participate in the study. A neuropsychological battery of cognitive assessments were conducted on all participants, and then stratified by cognitive function: no cognitive impairment, mild cognitive impairment and moderate to severe cognitive impairment. Anxiety and depression were assessed using the Hospital Anxiety and Depression Scale (HADS).

RESULTS

Most frequent ApoE genotype was e2/e3 in case (44%) and control groups (63%). ApoE allele e3 had the highest frequency for both groups with all stroke patients presenting with this allele and 86% for the control group (χ²  = 12.14, p < .0001). Stroke patients' non-carriers for ApoE allele e4 performed better on all cognitive measures but differences were not statistically significant (ns). Carriers of ApoE allele e2 in both groups had less mood symptoms compared to non-carriers.

DISCUSSION

ApoE genotype e3/e4 and e4/e4 was low in this Bahraini cohort explaining why there may been no significant associations found for this genotype variant with cognitive impairment. Further investigation of cognitive impairment and mood dysregulation with the different variants of the ApoE gene in general ageing and stroke populations is required from different ethno-cultural groups and geographical regions globally.

Impacts of Illiteracy on the Risk of Dementia: A Global Health Perspective

Despite its significance as a contributing factor for late-life dementia risk, illiteracy is frequently underappreciated in the management of dementia. In this study, we estimated the proportion of dementia cases attributable to illiteracy using the population attributable fraction (PAF), and calculated to what extent the monetary cost of dementia could be saved in the future by reducing illiteracy from the South Korean, Latin American, South Asian/Middle Eastern, and African populations. We collected necessary data from the 2011 United Nations Human Development Report and prevalence studies conducted in these regions. Additional variables not included in the above sources were estimated using a logit model under a "trend scenario"-based assumption. Around 16% of the total number of dementia cases in South Korea in 2015 can be attributed to illiteracy, with this figure predicted to decline to around 2% by 2050. This translates to a saving in dementia care costs of approximately 52 billion USD, providing we are successful in theoretically eradicating illiteracy as of 2015, in the population aged 65 years or under. Likewise, reducing illiteracy to 50% in Latin America, South Asia/The Middle East, and Africa by 2050 could generate further cost savings of between 71 and 244 billion, 13 and 94 billion, and 17 and 78 billion USD, respectively. Even public policies aimed solely at reducing illiteracy in the childhood, adolescent, or middle-aged population could potentially have a role in the primary prevention of dementia. Moving forward, governments will need to address this issue in a purposeful and systematic manner.

Alzheimer's Disease: Prototype of Cognitive Deterioration, Valuable Lessons to Understand Human Cognition

It is important for neurologists to become more familiar with neuropsychological evaluation for Alzheimer disease. The growth of this method in research, as an available, inexpensive, and noninvasive diagnostic approach, which can be administered even by non-specialist-trained examiners, makes this knowledge more necessary than ever. Such knowledge has a basic role in planning national programs in primary health care systems for prevention and early detection of Alzheimer disease. This is more crucial in developing countries, which have higher rates of dementia prevalence along with cardiovascular risk factors, lack of public knowledge about dementia, and limited social support. In addition compared to the neurological hard signs which are tangible and measurable, the concept of cognition seems to be more difficult for the neurologists to evaluate and for the students to understand. Dementia in general and Alzheimer's disease as the prototype of cognitive disorders specifically, play an important role to explore all domains of human cognition through its symptomatology and neuropsychological deficits.

Association Between Metacognition and Mood Symptoms Poststroke

INTRODUCTION

The link between metacognition and mood has been well established, particularly in other conditions with psychological comorbidity, however, there is no evidence regarding this association in the area of stroke.

AIM

The aim of this study was to examine the association between metacognition, based on the Self-Regulatory Executive Function model, and mood symptoms in the acute phase after stroke.

METHODS

One hundred thirty patients were recruited to a prospective stroke study in Bahrain, and n = 64 were assessed for mood and cognition. A neuropsychological battery of cognitive assessments included the following measures: the Mini-Mental State Examination, the Trail Making Test (A+B), and the Metacognition Questionnaire 30 (MCQ-30) for metacognition. The Hospital Anxiety and Depression Scale assessed mood symptoms, and stroke severity was measured using the National Institute of Health Stroke Severity Scale.

RESULTS

Total MCQ-30 scores were significantly associated with both anxiety (r = .47, P = .001) and depression (r = .54, P <. 0001). The MCQ-30 subscales' cognitive confidence, cognitive self-consciousness, and uncontrollability/danger were the specific factors to be associated with mood symptoms (P < .01). Global cognition (r =.32, P < .01), but not executive function, was significantly associated with depression only. Metacognition remained a statistically significant correlate with depression (β = .42, P < .0001) and anxiety (β = .51, P < .0001) after adjusting for education and global cognition.

DISCUSSION

Metacognition is a better determinant of mood symptoms after stroke, especially in regions where illiteracy levels are high in older populations, in comparison to executive function and global cognition.

Development and implementation of Persian test of Elderly for Assessment of Cognition and Executive function (PEACE)

Introduction

A considerable segment of the elderly population in Iran is illiterate, and it seems the existing neuropsychological screening tests are not very useful for detecting dementia in illiterate participants. The purpose of this study was to develop and validate a tool called Persian test of Elderly for Assessment of Cognition and Executive function (PEACE) for detecting dementia in both illiterate and literate participants.

Methods

First, in order to design some of the cognitive aspects of the PEACE assay, we considered other prevalent neuropsychological instruments, such as the General Practitioner assessment of Cognition (GPCOG), Functional Assessment Staging (FAST), Mini Mental State Examination (MMSE), and Wechsler Memory scale. The other domains of PEACE were designed according to our clinical proficiencies and the culture of the society. In the next step, the participants were classified into three distinct groups, i.e., the control group (n=33), the Mild Cognitive Impairment (MCI) group (n=30), and the Alzheimer’s group (n=38). All of the participants in each group were divided according to their educational level, i.e., illiterate, semi-literate, and literate.

Results

We developed PEACE consisting of 14 items, each of which represents a specific cognitive function, with a maximum score of 91. The 14 items are Orientation, Praxis, Attention and Concentration, Attention and Calculation, Memory, Similarity, Abstract Thinking, General Information, Language, Judgment, Gnosis, Planning (Sequencing), Problem Solving, and Animal Naming. PEACE scores are highly correlated with those of the MMSE (r=0.78). The optimal cut-off point of PEACE chosen for diagnosis of Alzheimer’s disease was 67.5 (sensitivity: 75.8%, specificity: 97.4%). The PEACE scores showed a significant difference between Participants with Alzheimer’s disease and the control group (p=0.0000) and the MCI group (p=0.003). In addition, there was no significant difference between illiterate and literate participants in the Alzheimer’s group. However, the PEACE scores differed significantly (p=0.0000) between illiterate and literate participants in the control group.

Conclusion

The PEACE addresses the limitations of existing tests and is appropriate for use in countries that have high rates of illiteracy. It is a valid screening mechanism for the detection of dementia in both illiterate and literate participants.