A systematic review of screening tools for predicting the development of dementia

Development of a new computer simulated environment to screen cognition: assessing the feasibility and acceptability of Leaf Café in younger and older adults

BACKGROUND

Existing traditional cognitive screening tools for dementia have various limitations, including overreliance on tests assessing verbal memory and, to a lesser extent, on some aspects of executive functioning. Comprehensive neuropsychological assessment is sensitive to impairment but time-intensive and expensive. Virtual reality may provide a dynamic and unique understanding of cognitive performance and increase the ecological validity of cognitive assessment. The use of virtual reality in screening for cognitive function in older persons is promising, but evidence for its use remains sparse.

OBJECTIVE

Our primary aim was to examine the feasibility and acceptability of a newly developed, virtual reality assessment module, 'Leaf Café', a computer-based program that assesses cognition in an engaging, efficient, and ecologically relevant way. The secondary aim was to assess the ability of the module to discriminate between performances of younger and older adults.

METHODS

A cross-sectional study was carried out in Sydney, Australia, targeting adults aged 18 years and above. Participants completed a traditional cognitive screening tool (Telephone Interview for Cognitive Status-Modified, TICS-M) and Leaf Café, a low-immersive virtual reality module designed to evaluate learning and memory, perceptual-motor function, and executive functioning. The total performance score for each participant, ranging from 0 to 180, was correlated with their cognitive performance assessed by TICS-M, using Pearson's correlation coefficient. Following module completion, participants were presented with an open and closed-question survey to capture their perceptions, attitudes, and feedback on the module, encompassing practicality, acceptability, and enjoyment. Both descriptive and content analyses were employed to interpret the obtained data.

RESULTS

A sample of 131 participants (mean age 54.9 years, SD = 20.8, range 20-85) took part. The majority were female (71.8%) and born in an English-speaking country (75.8%). The mean amount of time spent in the module was 32.8 min (SD = 13.3) with a mean module score of 107.6 (SD = 38.7). Most participants completed the highest level (5; 80.5%). There was a significant correlation between Leaf Café total scores with TICS-M cognitive scores overall, and for both younger (aged 18-64 years) and older adult (aged 65 + years) groups. No significant difference was found on performance between age groups on TICS-M performance, however, younger adults had significantly better performance on the Leaf Café module than older adults (M = 124.1 vs 95.9; p < .001). Participants had similar response proportions regarding user experience with most agreeing that the module was easy to use (84%) and to navigate (85%). Compared with younger adults, older adults had lower rates of agreement on the module's design (36.8% vs 64.3%; p = .020) and support experienced (20.5% vs 53.6%; p = .007). Participants highlighted the significance of practicality and the cognitive challenges presented by the module, in terms of memory strain and user interface concerns. Feedback encompassed different opinions on the usefulness of music, with suggestions for improvements centred around clearer instructions, varied game dynamics, and considerations for diverse user needs.

CONCLUSIONS

Leaf Café is a feasible and acceptable tool to be used for screening for cognitive impairment in older adults and has real-world assessment value. Further verification on the game's utility in detecting cognitive impairment is required.

Informant-based screening tools for dementia: an overview of systematic reviews

BACKGROUND

Informant-based questionnaires may have utility for cognitive impairment or dementia screening. Reviews describing the accuracy of respective questionnaires are available, but their focus on individual questionnaires precludes comparisons across tools. We conducted an overview of systematic reviews to assess the comparative accuracy of informant questionnaires and identify areas where evidence is lacking.

METHODS

We searched six databases to identify systematic reviews describing diagnostic test accuracy of informant questionnaires for cognitive impairment or dementia. We pooled sensitivity and specificity data for each questionnaire and used network approaches to compare accuracy estimates across the differing tests. We used grading of recommendations, assessment, development and evaluation (GRADE) to evaluate the overall certainty of evidence. Finally, we created an evidence 'heat-map', describing the availability of accurate data for individual tests in different populations and settings.

RESULTS

We identified 25 reviews, consisting of 93 studies and 13 informant questionnaires. Pooled analysis (37 studies; 11 052 participants) ranked the eight-item interview to ascertain dementia (AD8) highest for sensitivity [90%; 95% credible intervals (CrI) = 82-95; 'best-test' probability = 36]; while the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) was most specific (81%; 95% CrI = 66-90; 'best-test' probability = 29%). GRADE-based evaluation of evidence suggested certainty was 'low' overall. Our heat-map indicated that only AD8 and IQCODE have been extensively evaluated and most studies have been in the secondary care settings.

CONCLUSIONS

AD8 and IQCODE appear to be valid questionnaires for cognitive impairment or dementia assessment. Other available informant-based cognitive screening questionnaires lack evidence to justify their use at present. Evidence on the accuracy of available tools in primary care settings and with specific populations is required.

Does Your Loved One With Cognitive Symptoms Need to See a Doctor? Check It Online

Widespread access to emerging information and communication technologies (ICT) allows its use for the screening of diseases in the general population. At the initiative of the Spanish Confederation of Associations of Families of People with Alzheimer’s disease and other dementias (CEAFA), a website (http://www.problemasmemoria.com) has been created that provides information about Alzheimer’s disease and includes questionnaires to be completed by family or friends concerned about memory problems of a relative. A cross-sectional, randomized, multicenter study was performed to evaluate feasibility, validity, and user satisfaction with an electronic method of completion vs. the current method of paper-based questionnaires for clinically dementia screening completed by the informants: the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) and the Alzheimer’s disease-8 screening test (AD8). A total of 111 pairs were recruited by seven memory clinics. Informants completed IQCODE and AD8 questionnaires both in their paper and electronic versions. The correlation between paper and electronic versions was significantly positive for IQCODE (r = 0.98; p < 0.001) and AD8 (r = 0.96; p < 0.001). The execution time did not differ significantly, and participants considered their use equally easy. This study shows that an electronic version of the IQCODE and AD8 questionnaires is suitable for its online use via the internet and achieves the same results as the traditional paper versions.

Validation of the Chinese version of Addenbrooke's cognitive examination III for detecting mild cognitive impairment

OBJECTIVES

To evaluate the reliability and validity of Chinese version of Addenbrooke's Cognitive Examination III (ACE-III-CV) in the identification of mild cognitive impairment (MCI), and further investigate the optimal cutoff scores according to different age and education level.

METHOD

A total of 716 individuals aged from 50 to 90 years old were recruited through internet-based and print advertisements, including 431 cognitively normal controls (NC) and 285 individuals with MCI according to an actuarial neuropsychological method put forward by Jak and Bondi. Besides the cognitive screening tests of ACE-III-CV, Mini-Mental State Examination (MMSE) and Chinese version of Montreal Cognitive Assessment-Basic (MoCA-BC), all the participants underwent a battery of standardized neuropsychological tests. Validations of the ACE-III-CV, MMSE, and MoCA-BC for detecting MCI from NC were determined by Receiver operating characteristic (ROC) curves.

RESULTS

ACE-III-CV had a good reliability (Cronbach's coefficient α = 0.807, intraclass correlation coefficients for interrater and test-retest reliability were 0.95 and 0.93). According to the area under ROC curve (AUC), ACE-III-CV and MoCA-BC showed better ability than MMSE in detecting MCI. No significant difference was found between ACE-III-CV and MoCA-BC. The optimal cutoff scores of ACE-III-CV for screening MCI were 72 for individuals with 1-9 years of education, 78 for individuals with 10-15 years of education, and 80 for individuals with more than 16 years of education.

CONCLUSION

The Chinese version of ACE-III-CV is a reliable and valid screening tool for detecting MCI. The optimal cutoff scores are closely related with education level.

Validation of a modified Chinese version of Mini-Addenbrooke's Cognitive Examination for detecting mild cognitive impairment

BACKGROUND

For detecting mild cognitive impairment (MCI), brief cognitive screening tools are increasingly required for the advantage of time saving and no need for special equipment or trained raters. We aimed to develop a modified Chinese version of Mini-Addenbrooke's Cognitive Examination (C-MACE) and further evaluate its validation in detecting MCI.

METHODS

A total of 716 individuals aged from 50 to 90 years old were recruited, including 431 cognitively normal controls (NC) and 285 individuals with MCI. The effect size of Cramer's V was used to explore which items in the Chinese version of Addenbrooke's Cognitive Examination-III (ACE-III-CV) best associated with MCI and to form the C-MACE. Receiver operating characteristic (ROC) analyses were carried out to explore the ability of C-MACE, ACE-III-CV, Chinese version of Montreal Cognitive Assessment-Basic (MoCA-BC), and Mini-Mental State Examination (MMSE) in discriminating MCI from NC.

RESULTS

Five items with greatest effect sizes of Cramer's V were selected from ACE-III-CV to form the C-MACE: Memory Immediate Recall, Memory Delayed Recall, Memory Recognition, Verbal Fluency Animal and Language Naming. With a total score of 38, the C-MACE had a satisfactory classification accuracy in detecting MCI (area under the ROC curve, AUC = 0.892), superior to MMSE (AUC = 0.782) and comparable to ACE-III-CV (AUC = 0.901) and MoCA-BC (AUC = 0.916). In the subgroup of Age > 70 years, Education ≤ 12 years, the C-MACE got a highest classification accuracy (AUC = 0.958) for detecting MCI.

CONCLUSION

In the Chinese-speaking population, C-MACE derived from ACE-III-CV may identify MCI with a good classification accuracy, especially in aged people with low education.

Optimizing the diagnosis and management of dementia within primary care: a systematic review of systematic reviews

Background

To understand how best to approach dementia care within primary care and its challenges, we examined the evidence related to diagnosing and managing dementia within primary care.

Methods

Databases searched include: MEDLINE, Embase, PsycINFO and The Cochrane Database of Systematic Reviews from inception to 11 May 2020. English-language systematic reviews, either quantitative or qualitative, were included if they described interventions involving the diagnosis, treatment and/or management of dementia within primary care/family medicine and outcome data was available. The risk of bias was assessed using AMSTAR 2. The review followed PRISMA guidelines and is registered with Open Science Framework.

Results

Twenty-one articles are included. The Mini-Cog and the MMSE were the most widely studied cognitive screening tools. The Abbreviated Mental Test Score (AMTS) achieved high sensitivity (100 %, 95 % CI: 70-100 %) and specificity (82 %, 95 % CI: 72-90 %) within the shortest amount of time (3.16 to 5 min) within primary care. Five of six studies found that family physicians had an increased likelihood of suspecting dementia after attending an educational seminar. Case management improved behavioural symptoms, while decreasing hospitalization and emergency visits. The primary care educational intervention, Enhancing Alzheimer’s Caregiver Health (Department of Veterans Affairs), was successful at increasing carer ability to manage problem behaviours and improving outcomes for caregivers.

Conclusions

There are clear tools to help identify cognitive impairment in primary care, but strategies for management require further research. The findings from this systematic review will inform family physicians on how to improve dementia diagnosis and management within their primary care practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12875-021-01461-5.

Visiting Out-of-Home Places When Living With Dementia: A Cross-Sectional Observational Study: Visiter des lieux hors du domicile lorsque l'on vit avec une démence: étude transversale observationnelle

BACKGROUND.

Persons living with dementia face a reduction of their life space outside home and disengagement from participation, linked to places visited.

PURPOSE.

This study explored stability and change in perceived participation in places visited outside home and its relationship with occupational gaps among older adults.

METHOD.

Older adults living with (n = 35) or without (n = 35) dementia were interviewed using the Participation in ACTivities and Places OUTside Home (ACT-OUT) questionnaire and the Occupational Gaps Questionnaire (OGQ). Data analysis used descriptive and inferential statistics.

FINDINGS.

The group of people living with dementia reported significantly fewer places (p < .001) visited than the comparison group and having abandoned more places visited (p < .001) than the comparison group. The number of occupational gaps was significantly different between groups (p < .001).

IMPLICATIONS.

Participation outside home is not influenced in a uniform and straightforward way for persons living with dementia; the shrinking world effect appears differently in relation to types of places.

Tracking Cognitive Performance in the General Population and in Patients with Mild Cognitive Impairment with a Self-Applied Computerized Test (Brain on Track)

Repeated measurements could be helpful to identify patients with early cognitive decline. We compare the variation of cognitive performance over one year in patients with mild cognitive impairment (MCI) and healthy individuals using the Brain on Track self-applied computerized test (BoT). The study was initiated 30 patients with probable MCI and 377 controls from a population-based cohort, who performed the BoT test from home every three months for one year. The scores were compared using a linear mixed-effects model. All participants increased their scores in the first tests, after 120 days MCI patients started to decline, with a statistically significant higher rate. The area under the curve to detect MCI was 0.94. We identified a significant decline in cognitive performance over one year in patients with MCI using BoT and the test presented a high discriminative ability.

Intention to Be Screened for Alzheimer's Disease in Nondemented Older Adults: Integrated Behavioral Model and Self-Efficacy as Mediation Effect

The study explored factors associated with intention to be screened for Alzheimer's disease (AD). The study also examined whether self-efficacy mediates the relationship between knowledge about screening and the intention to be screened for AD. A population-based, random-digit dialing survey was performed and 1,043 responses were collected from a sample of nondemented persons (50 years or older) living in urban, suburban, and rural areas in a Midwestern state. The findings showed that participants who were younger and who had higher levels of (a) perceived benefits and barriers, (b) social support, and (c) self-efficacy reported higher levels of intention to be screened for AD. Older adults with positive life orientation reported greater intention to be screened for AD, whereas depressed participants were more likely to report a plan to be screened for AD. Self-efficacy mediated the relationship between knowledge about screening and intention to be screened. Older adults were more likely to report intention to be screened when they had positive attitudes about the screen and believed that they could receive the screen. The intention to be screened for AD could serve public awareness by defining effective ways to assist older adults to seek a cognitive screen.

Early detection of cognitive disturbances in mild cognitive impairment: a systematic review of observational studies

Mild cognitive impairment (MCI) is an intermediate state between normal cognition and early dementia and is not considered as a typical outcome of brain aging. It has been estimated that 10% to 20% of individuals above 65 years of age will be diagnosed as having MCI. The increased rate of dementia and the importance of early detection of its forerunners have encouraged researchers to focus on detecting MCI and modifiable risk factors with the hope of developing better ways of managing dementia and its consequences. The main aim of this study was to systematically review the related literature concerning the cognitive changes in the spectrum of cognitive aging to cognitive impairment. Articles included in this review were identified through searching the databases of PubMed, Psych Info, Embase, ProQuest, and Scopus. Many domains like verbal memory, language, executive function, visual memory, attentional skills, and working memory showed acceptable predictive power. Testing subdomains such as executive function, speed of processing, working memory and semantic language are critical and others may indicate some suggestions for further clinical deteriorations in normal individuals. Although various cognitive instruments have been used for evaluation of impaired cognitive domains, it remains challenging to select the most appropriate ones having high-level accuracy and their related cognitive subdomains. It also revealed that none of the identified cognitive domains solely fulfilled the criteria for MCI screening; in clinical settings, multiple neuropsychological batteries may be used for one single cognitive domain, while longitudinal studies prefer the use of at least two cognitive measures for each domain to improve accuracy and research settings might focus on only a single neuropsychological test. However, along with episodic memory, testing for amnestic MCI, executive function could increase the chance of early detection of MCI. Executive control has been found to deteriorate the earliest in MCI patients.

MRI and cognitive scores complement each other to accurately predict Alzheimer's dementia 2 to 7 years before clinical onset

BACKGROUND

Predicting cognitive decline and the eventual onset of dementia in patients with Mild Cognitive Impairment (MCI) is of high value for patient management and potential cohort enrichment in pharmaceutical trials. We used cognitive scores and MRI biomarkers from a single baseline visit to predict the onset of dementia due to AD in an amnestic MCI (aMCI) population over a nine-year follow-up period.

METHOD

All aMCI subjects from ADNI1, ADNI2, and ADNI-GO with available baseline neurocognitive scores and T1w MRI were included in the study (n = 756). We built a Naïve Bayes classifier for every year over a 9-year follow-up period and tested each one with Leave one out cross validation.

RESULTS

We reached 87% prediction accuracy at five years follow-up with an AUC > 0.85 from two to seven years (peaking at 0.92 at five years). Both neurocognitive scores and MRI biomarkers were needed to make the prognostic models highly sensitive and specific, especially for longer follow-ups. MRI features are more sensitive, while cognitive features bring specificity to the prediction.

CONCLUSION

Combining cognitive scores and MRI biomarkers yield accurate prediction years before onset of dementia. Such a tool may be helpful in selecting patients that would most benefit from lifestyle changes, and eventually early treatments that would slow cognitive decline and delay the onset of dementia.

Cognitive assessment tools for mild cognitive impairment screening

Mild cognitive impairment (MCI) is a clinical condition with a high risk of progression to dementia. Due to lack of effective disease-modifying therapies for advanced dementia, diagnosis and disease intervention at an early stage, particularly at MCI stage, has been widely accepted as a critical strategy in disease management that could potentially affect long-term outcome. However, there is currently no consensus on guidelines for routine screening of MCI, resulting in a considerable number of patients with undiagnosed MCI from community. In addition, the use of different screening guidelines leads to difficulties in comparing different studies. A variety of screening tools have been utilized; however, the sensitivity and specificity vary greatly among these tools. By summarizing the sensitivity, specificity and time efficiency for common MCI screening tools, which are key factors to be taken into consideration when making selections and combinations of screening tools, this review suggests the use of a combination of two self-administered highly sensitive tools, p-AD8 + IQCODE (informant questionnaire on cognitive decline in the elderly individuals) in initial screening, as well as a combination of two highly specific widely covered tools, DemTect + MoCA (Montreal cognitive assessment) or memory and executive screening (MES) + MoCA in secondary screening. In addition, this review also proposes a screening flowchart for MCI, aiming to build a sensitive and time efficient way for recruiting subjects for subsequent investigation and disease differentiation.

Validity of screening tools for dementia and mild cognitive impairment among the elderly in primary health care: a systematic review

OBJECTIVES

This systematic review aims to provide updated and comprehensive evidence on the validity and feasibility of screening tools for mild cognitive impairment (MCI) and dementia among the elderly at primary healthcare level.

STUDY DESIGN

A review of articles was performed.

METHODS

A search strategy was used by using electronic bibliographic databases including PubMed, Embase and CENTRAL for published studies and reference list of published studies. The articles were exported to a bibliographic database for further screening process. Two reviewers worked independently to screen results and extract data from the included studies. Any discrepancies were resolved and confirmed by the consensus of all authors.

RESULTS

There were three screening approaches for detecting MCI and dementia - screening by a healthcare provider, screening by a self-administered questionnaire and caretaker informant screening. Montreal Cognitive Assessment (MoCA) was the most common and preferable tool for MCI screening (sensitivity [Sn]: 81-97%; specificity [Sp]: 60-86%), whereas Addenbrooke's Cognitive Examination (ACE) was the preferable tool for dementia screening (Sn: 79-100%; Sp: 86%).

CONCLUSION

This systematic review found that there are three screening approaches for detecting early dementia and MCI at primary health care. ACE and MoCA are recommended tools for screening of dementia and MCI, respectively.

Instrument Development and Testing for Selection of Nursing Preceptors

The purpose of this pilot study was to develop and test a preceptor selection instrument for validity and reliability. Using a valid and reliable instrument to help identify and select an appropriate nurse preceptor supports the success of both the preceptor and the new nurse graduate. The 14-item Cotter Preceptor Selection Instrument was developed to assess attributes of potential preceptor candidates. Use of a robust and user-friendly instrument can provide nursing leadership with a consistent, measurable, and collaborative process for selecting preceptors.

Effects of physical exercise programs on cognitive function in Parkinson's disease patients: A systematic review of randomized controlled trials of the last 10 years

Background

Given the relative importance of cognitive impairment, there was considerable interest in identifying the cognitive profile of PD patients, in order to ensure specific and appropriate therapeutic interventions.

Purpose

To determine the effects of physical exercise programs on cognitive function in PD patients, compared with the control group.

Data sources

Medline, Cochrane, Scopus, PEDro and Web of Science (last searched in September 2016).

Study selection

Randomized clinical trials examining the effects of physical exercise programs and cognitive function in PD patients. Nine studies fulfilled the selection criteria and were included in this review.

Data extraction

Characteristics of the publication, characteristics of the participants, test used for cognitive screening, cognitive domain assessed, tools used to assess cognitive function, characteristics of the experimental intervention, characteristics of the control group, mean results and standard deviation of function cognitive. The PEDro score was used to evaluate methodological quality.

Data synthesis

Most eligible studies showed good methodological quality based on the PEDro scale. Studies have shown that adapted tango for PD patients, cognitive training combined with motor training, and treadmill training promote the preservation or improvement of cognitive function in PD patients.

Limitations

The diversity of cognitive tests used to assess cognitive function and the high heterogeneity identified between the physical exercise programs.

Conclusions

Physical exercise programs promote positive and significant effects on global cognitive function, processing speed, sustained attention and mental flexibility in PD patients, at a mild to moderate stage for patients with a 6-year clinical diagnosis of PD. However, treadmill training performed 3 times a week for about 60 minutes and for a period of 24 weeks produced larger improvements in cognition.

Neuropsychological Measures that Predict Progression from Mild Cognitive Impairment to Alzheimer's type dementia in Older Adults: a Systematic Review and Meta-Analysis

This study aimed to determine the extent to which cognitive measures can predict progression from mild cognitive impairment (MCI) to Alzheimer’s type dementia (AD), assess the predictive accuracy of different cognitive domain categories, and determine whether accuracy varies as a function of age and length of follow-up. We systematically reviewed and meta-analyzed data from longitudinal studies reporting sensitivity and specificity values for neuropsychological tests to identify individuals with MCI who will develop AD. We searched articles in Medline, Cochrane, EMBASE, PsycINFO, and the Web of Science. Methodological quality was assessed using the STARDem and QUADAS standards. Twenty-eight studies met the eligibility criteria (2365 participants) and reported predictive values from 61 neuropsychological tests with a 31-month mean follow-up. Values were pooled to provide combined accuracy for 14 cognitive domains. Many domains showed very good predictive accuracy with high sensitivity and specificity values (≥ 0.7). Verbal memory measures and many language tests yielded very high predictive accuracy. Other domains (e.g., executive functions, visual memory) showed better specificity than sensitivity. Predictive accuracy was highest when combining memory measures with a small set of other domains or when relying on broad cognitive batteries. Cognitive tests are excellent at predicting MCI individuals who will progress to dementia and should be a critical component of any toolkit intended to identify AD at the pre-dementia stage. Some tasks are remarkable as early indicators, whereas others might be used to suggest imminent progression.

Mesiotemporal atrophy and hippocampal diffusivity distinguish amnestic from non-amnestic vascular cognitive impairment

Background and purpose

The role of clinical factors, cerebral infarcts and hippocampal damage in vascular cognitive impairment (VCI) subtypes remains unclear.

Methods

Non‐demented patients with carotid stenosis and recent transient ischemic attack/stroke had cognitive assessment and brain magnetic resonance imaging (MRI). Amnestic VCI was defined as memory impairment; non‐amnestic VCI was any other subdomain impairment. Associations of MRI metrics [log‐transformed total ischemic lesion load (log TILL), mesiotemporal atrophy (MTA) score, hippocampal mean diffusivity (hipMD)] with cognitive performance were assessed.

Results

A hundred and eight patients, 47 with amnestic VCI and 21 with non‐amnestic VCI, were assessed. A higher MTA (odds ratio 12.89, P = 0.001) and left hipMD (odds ratio 4.43, P = 0.003) contributed to amnestic VCI versus normal. Age‐adjusted fluency correlated with log TILL (P = 0.002). Age‐adjusted memory was associated with left hipMD (P = 0.001), MTA (P < 0.001) but not log TILL (P = 0.14). Left hipMD, MTA and smoking showed classification potential between amnestic VCI versus normal (area 0.859, P < 0.001).

Conclusions

Neuroimaging assists stratification in amnestic VCI characterized by hippocampal changes and in non‐amnestic VCI by higher ischemic burden. MTA and hippocampal diffusivity show diagnostic biomarker potential.

Development of a self-administered web-based test for longitudinal cognitive assessment

Sequential testing with brief cognitive tools has been recommended to improve cognitive screening and monitoring, however the few available tools still depend on an external evaluator and periodic visits. We developed a self-administered computerized test intended for longitudinal cognitive testing (Brain on Track). The test can be performed from a home computer and is composed of several subtests, expected to evaluate different cognitive domains, all including random elements to minimize learning effects. An initial (A) and a refined version of the test (B) were applied to patients with mild cognitive impairment or early dementia (n = 88) and age and education-matched controls. A subsample of a population-based cohort (n = 113) performed the test at home every three months to evaluate test-retest reliability. The test’s final version Cronbach’s alpha was 0.90, test scores were significantly different between patients and controls (p = 0.001), the area under the receiver operating characteristic curve was 0.75 and the smallest real difference (43.04) was lower than the clinical relevant difference (56.82). In the test-retest reliability analysis 9/10 subtests showed two-way mixed single intraclass consistency correlation coefficient >0.70. These results imply good internal consistency, discriminative ability and reliability when performed at home, encouraging further longitudinal clinical and population-based studies.

Psychometric Evaluation of the Cognitive State Test (COST) in a Sample of Iranian Elderly People

Background

An absolute prerequisite to the effective management of dementia is its early diagnosis. Successful dementia screening requires precise and sensitive instruments that can be completed even by illiterate elderly people.

Objectives

The aim of this study was to evaluate the psychometric properties of the Persian version of the cognitive state test (COST).

Materials and Methods

This methodologic study was conducted in Kashan, Iran, during 2013 - 2014. A purposeful sample of 150 healthy elderly people and 50 elderly patients with dementia was recruited. After translating the instrument by using the standard forward-backward technique, we assessed its qualitative and quantitative face and content validity. The validity of the test was assessed by using the concurrent validity and the exploratory factor analysis. We also calculated Cronbach’s alpha and employed the test-retest method for evaluating the internal consistency and the stability of the test, respectively. Study data were analyzed by using the SPSS v16.0, the Spearman-Brown, and the intraclass correlation coefficient tests and the principal components factor analysis with varimax rotation.

Results

The Persian COST consists of nineteen items. The impact scores, the content validity ratios and the content validity indices of all test items were greater than 4.5, 0.69, and 0.84, respectively. The COST had a significant correlation with the clinical dementia rating (rS = -0.76, P value < 0.001), indicating an acceptable concurrent validity for the test. The exploratory factor analysis revealed a five-factor structure that explained 60.59% of the total variance of the total cognitive state score. The Cronbach’s alpha, Spearman-Brown, and interclass correlation coefficients were 0.82, 0.95, and 0.88, respectively (P value < 0.001).

Conclusions

The Persian version of the COST can be used as a valid and reliable instrument for assessing cognitive state and screening dementia in literate and illiterate elderly people.

Validation of the Chinese version of Addenbrooke's cognitive examination-revised for screening mild Alzheimer's disease and mild cognitive impairment

BACKGROUND/AIMS

As a suitable test to screen for Alzheimer's disease (AD) or mild cognitive impairment (MCI), studies to validate the Chinese version of Addenbrooke's Cognitive Examination-Revised (ACE-R) are rare.

METHODS

A total of 151 subjects were recruited and the neuropsychological assessments were employed. One-way analysis of variance and Bonferroni correction were used to compare scores of different psychometric scales. Intraclass correlation coefficient (ICC) and Cronbach's coefficient α were used to evaluate the reliability of psychometric scales. The validity of ACE-R to screen for mild AD and amnestic subtype of MCI (a-MCI) was assessed by receiver operating characteristic (ROC) curves.

RESULTS

The Chinese ACE-R had good reliability (inter-rater ICC = 0.994; test-retest ICC = 0.967) as well as reliable internal consistency (Cronbach's coefficient α = 0.859). With its cutoff of 67/68, the sensitivity (0.920) and specificity (0.857) were lower than for the Mini-Mental State Examination (MMSE) cutoff (sensitivity 1.000 and specificity 0.937) to screen for mild AD. However, the sensitivity of ACE-R to screen for a-MCI was superior to the MMSE with a cutoff of 85/86. The specificity of ACE-R was lower than that of the MMSE to screen for a-MCI. The area under the ROC curve of ACE-R was much larger than that of the MMSE (0.836 and 0.751) for detecting a-MCI rather than mild AD.

CONCLUSION

The Chinese ACE-R is a reliable assessment tool for cognitive impairment. It is more sensitive and accurate in screening for a-MCI rather than for AD compared to the MMSE.

Cognitive screening for dementia in primary care: a systematic review

BACKGROUND

Identifying dementia in primary care could minimize the impact of a late intervention; however, it shows high rates of misdiagnosis. One of the reasons seems to be the lack of knowledge of adequate cognitive screening instruments. This is a systematic review of the available instruments for the primary care context.

METHOD

For this systematic review, articles were collected according to the following combined key terms: "cognitive screening" and "dementia" and "primary care" and "review". Studies should be reviews focusing on cognitive screening instruments best used in primary care setting.

RESULTS

Thirteen reviews were selected. In total, it was considered 34 cognitive screening instruments. Half of the instruments can be applied in an adequate time-limit for primary care context. Memory is the most commonly assessed cognitive function (91%). Almost half of the tests are mentioned to have influence of education or cultural factors (44%).

CONCLUSION

Tests such as 6CIT, AMT, GPCOG, Mini-Cog, MIS, MoCA, and STMS seem to be good alternatives to the use of the Mini-Mental State Examination when considering factors such as application time, sensitivity, specificity, and number of studies. However, there is a wide range of tests with different characteristics, therefore it is recommended that the professional gets some expertise in a few number of instruments in order to be able to choose which to use, or use in combination, depending on the setting and the profile of the patient.

Diagnostic tools for alzheimer's disease dementia and other dementias: an overview of diagnostic test accuracy (DTA) systematic reviews

BACKGROUND

Dementia includes a group of neurodegenerative disorders characterized by progressive loss of cognitive function and a decrease in the ability to perform activities of daily living. Systematic reviews of diagnostic test accuracy (DTA) focus on how well the index test detects patients with the disease in terms of figures such as sensitivity and specificity. Although DTA reviews about dementia are essential, at present there is no information about their quantity and quality.

METHODS

We searched for DTA reviews in MEDLINE (1966-2013), EMBASE (1980-2013), The Cochrane Library (from its inception until December 2013) and the Database of Abstracts of Reviews of Effects (DARE). Two reviewers independently assessed the methodological quality of the reviews using the AMSTAR measurement tool, and the quality of the reporting using the PRISMA checklist. We describe the main characteristics of these reviews, including basic characteristics, type of dementia, and diagnostic test evaluated, and we summarize the AMSTAR and PRISMA scores.

RESULTS

We selected 24 DTA systematic reviews. Only 10 reviews (41.6%), assessed the bias of included studies and few (33%) used this information to report the review results or to develop their conclusions Only one review (4%) reported all methodological items suggested by the PRISMA tool. Assessing methodology quality by means of the AMSTAR tool, we found that six DTA reviews (25%) pooled primary data with the aid of methods that are used for intervention reviews, such as Mantel-Haenszel and separate random-effects models (25%), while five reviews (20.8%) assessed publication bias by means of funnel plots and/or Egger's Test.

CONCLUSIONS

Our assessment of these DTA reviews reveals that their quality, both in terms of methodology and reporting, is far from optimal. Assessing the quality of diagnostic evidence is fundamental to determining the validity of the operating characteristics of the index test and its usefulness in specific settings. The development of high quality DTA systematic reviews about dementia continues to be a challenge.

Should the mini-mental state examination be retired?

INTRODUCTION

Short cognitive tests are routinely used in clinical practice to detect and screen for cognitive impairment and dementia. These cognitive tests should meet minimum criteria for both applicability and psychometric qualities.

DEVELOPMENT

The Mini-Mental State Examination (MMSE) is the most frequently applied short cognitive test, and the article introducing it remains a milestone in the history of medicine. Its main advantages are its widespread use and the extensive empirical evidence that supports it. However, the MMSE has important shortcomings, including lack of standardisation, its lack of suitability for illiterate subjects, the considerable effect of socio-educational variables on results, and its limited effectiveness for detecting cognitive impairment. Lastly, since the test is copyright-protected, using it is necessarily either costly or fraudulent. Newer available instruments do not share these shortcomings and have demonstrated greater diagnostic accuracy for detecting cognitive impairment and dementia, as well as being more cost-effective than the MMSE CONCLUSION: It is time to acknowledge the MMSE's important role in the history of medicine and grant it a deserved and honourable retirement. Its place will be taken by more effective instruments that require less time, are user-friendly and free of charge, can be applied to all individuals, and yield more equitable outcomes.

Cognitive approaches to early Alzheimer's disease diagnosis

In this article, cognitive measures in the screening of individuals at risk for Alzheimer disease (AD) are reviewed. Use of cognitive tasks in identifying clinical cases of AD is considered, as well as methods for detecting those in the prodromal stages of the disease, including cognitive screening instruments. Traditional assessments, such as the mini-mental state examination, as well as contemporary computerized screening instruments, are examined. Areas of cognition for investigation in the detection of prodromal AD are recommended. The prospects for general cognitive screening are reviewed, and more engaging technologies to tests individuals at risk for developing AD are recommended.