Mini-Addenbrooke's Cognitive Examination Research Articles

Higher purpose in life and education were associated with better cognition among older adults.

With aging, some cognitive abilities change because of neurobiological processes. Cognition may also be influenced by psychosocial aspects. To describe the relationship between a measure of neuroticism, depression symptoms, purpose in life, and cognitive performance in community-dwelling older adults. This was a cross-sectional analysis based on the data from the second wave of the Frailty in Brazilian Older Adults (FIBRA) study, carried out between 2016 and 2017. The sample consisted of 419 older people (≥ 72 years old) cognitively unimpaired and mostly with low education. The variables of interest were sociodemographic, Neuroticism domain from the NEO-PI-R, Geriatric Depression Scale (GDS), Purpose in Life (PiL) scale, and a cognitive composite score which included the Mini-Mental State Examination (MMSE), and the scores for the sub-items of the Mini-Addenbrooke's Cognitive Examination (M-ACE), namely, Verbal Fluency (VF) - Animal, Clock Drawing Test (CDT), Episodic Memory (name and address). There was a greater number of women (70%), with older age (median = 80 years, IQR = 77-82), and low education (median = 4 years, IQR = 2-5). In the bivariate correlations, years of education (ρ = 0.415; p < 0.001) and PiL (ρ = 0.220; p < 0.001) were positively associated with cognition. Neuroticism (ρ = -0.175; p < 0.001) and depression symptoms (ρ = -0.185; p < 0.001) were negatively associated with cognition. In the logistic regression, after including confounding variables, the associations between cognition and PiL (OR = 2.04; p = 0.007) and education (OR = 1.32; p < 0.001) remained significant. Low PiL and low education levels were associated with worse cognition among older adults. Such results may be of relevance in programs that aim to improve cognition among older adults.

Validity and reliability of the Persian version of Mini-Addenbrooke’s Cognitive Examination among Iranian highly educated older adults

Background Limited studies have examined psychometric properties of dementia screening tools in university-educated older adults. We aimed to examine this population’s diagnostic accuracy of the Iranian version of Mini-Addenbrooke’s Cognitive Examination (M-ACE). Materials & methods Eighty-seven participants with over 60 years with university education were divided into three groups: Major neurocognitive disorder, mild neurocognitive disorder, and healthy control. The Iranian version of M-ACE, the Mini-Mental State Examination (MMSE), the Geriatric Depression Scale (GDS), the Activities of Daily Living-Instrumental Activities of Daily Living (ADL-IADL) scale and Diagnostic and Statistical Manual of Mental Disorders 5th edition-Text Revision (DSM-5) were used. Results A high internal reliability of questionnaire was confirmed by Cronbach’s alpha coefficient. One-way ANOVA and post hoc analysis confirmed a significant difference between study groups. The scores of M-ACE were found to have a high positive correlation with MMSE, IADL, ADL, and a moderate correlation with GDS. The optimal cutoff score of M-ACE to screen for mild and major neurocognitive disorders were 27.5 and 20.5, respectively. Conclusion The M-ACE was a concise and reliable tool used to identify neurocognitive disorders in highly educated older adults, but they should be evaluated at a higher traditional cut score in earlier stages.

Mini-ACE: Validation Study Among Older People in Long-Term Care.

The Mini-Addenbrooke's Cognitive Examination (M-ACE) is a valid and reliable tool that accurately differentiates various types of cognitive impairment from Normal-cognition assessed in multiple settings. However, its validity among older individuals in long-term care (LTC) was not yet established. Therefore, we sought to assess the Portuguese M-ACE's validity, reliability, and accuracy in detecting cognitive impairment no-dementia (CIND) in LTC users. A comprehensive assessment was performed on 196 LTC Portuguese users aged ≥ 60 years, among whom 71 had Normal-cognition, and 125 had CIND. The M-ACE was found to be reliable (McDonald's ω = .86, Cronbach's α = .85) and consistent over time (r = .72; ICC = .83) and between raters (k = .92). Strong correlations with related measures supported construct validity (both r = .67). The M-ACE accurately distinguished CIND from Normal-cognition with a cut-off of 17 points (AUC = 0.81, Sensitivity = 81.7%, Specificity = 74.4%). Our findings suggest that the Portuguese M-ACE is a valid and reliable cognitive assessment tool for LTC users, allowing for accurate differentiation between CIND and Normal-cognition. Thus, the M-ACE's use could contribute to the early detection and intervention of cognitive disorders, especially among older adults in LTC.

Cut-off scores for mild and moderate dementia on the Addenbrooke's Cognitive Examination-III and the Mini-Addenbrooke's Cognitive Examination compared with the Mini-Mental State Examination.

We aimed to establish cut-off scores to stage dementia on the Addenbrooke's Cognitive Examination-III (ACE-III) and the Mini-Addenbrooke's Cognitive Examination (M-ACE) compared with scores traditionally used with the Mini-Mental State Examination (MMSE). Our cross-sectional study recruited 80 patients and carers from secondary care services in the UK. A score ≤76 on the ACE-III and ≤19 on the M-ACE correlated well with MMSE cut-offs for mild dementia, with a good fit on the receiver operating characteristic analysis for both the ACE-III and M-ACE. The cut-off for moderate dementia had lower sensitivity and specificity. There were low to moderate correlations between the cognitive scales and scales for everyday functioning and behaviour. Our findings allow an objective interpretation of scores on the ACE-III and the M-ACE relative to the MMSE, which may be helpful for clinical services and research trials.

Remote assessment of cognition and quality of life following radiotherapy for nasopharyngeal carcinoma: deep-learning-based predictive models and MRI correlates.

Irradiation of the brain regions from nasopharyngeal carcinoma (NPC) radiotherapy (RT) is frequently unavoidable, which may result in radiation-induced cognitive deficit. Using deep learning (DL), the study aims to develop prediction models in predicting compromised cognition in patients following NPC RT using remote assessments and determine their relation to the quality of life (QoL) and MRI changes. Seventy patients (20-76 aged) with MRI imaging (pre- and post-RT (6months-1year)) and complete cognitive assessments were recruited. Hippocampus, temporal lobes (TLs), and cerebellum were delineated and dosimetry parameters were extracted. Assessments were given post-RT via telephone (Telephone Interview Cognitive Status (TICS), Telephone Montreal Cognitive Assessment (T-MoCA), Telephone Mini Addenbrooke's Cognitive Examination (Tele-MACE), and QLQ-H&N 43). Regression and deep neural network (DNN) models were used to predict post-RT cognition using anatomical and treatment dose features. Remote cognitive assessments were inter-correlated (r > 0.9). TLs showed significance in pre- and post-RT volume differences and cognitive deficits, that are correlated with RT-associated volume atrophy and dose distribution. Good classification accuracy based on DNN area under receiver operating curve (AUROC) for cognitive prediction (T-MoCA AUROC = 0.878, TICS AUROC = 0.89, Tele-MACE AUROC = 0.919). DL-based prediction models assessed using remote assessments can assist in predicting cognitive deficit following NPC RT. Comparable results of remote assessments in assessing cognition suggest its possibility in replacing standard assessments. Application of prediction models in individual patient enables tailored interventions to be provided in managing cognitive changes following NPC RT.

Remote assessment of cognition and quality of life following radiotherapy for glioma: deep-learning-based predictive models and MRI correlates.

Glioma irradiation often unavoidably damages the brain volume and affects cognition. This study aims to evaluate the relationship of remote cognitive assessments in determining cognitive impairment of irradiated glioma patients in relation to the quality of life and MRI changes. Thirty patients (16-76 aged) with two imaging (pre- and post-RT) and completed cognitive assessments were recruited. Cerebellum, right and left temporal lobes, corpus callosum, amygdala and spinal cord were delineated and their dosimetry parameters were collected. Cognitive assessments were given post-RT via telephone (Telephone Interview Cognitive Status (TICS), Telephone Montreal Cognitive Assessment (T-MoCA), Telephone Mini Addenbrooke's Cognitive Examination (Tele-MACE)). Regression models and deep neural network (DNN) were used to evaluate the relationship between brain volume, cognition and treatment dose in patients. Cognitive assessments were highly inter-correlated (r > 0.9) and impairment was shown between pre- and post-RT findings. Brain volume atrophy was shown post-RT, and cognitive impairments were correlated with radiotherapy-associated volume atrophy and dose-dependent in the left temporal lobe, corpus callosum, cerebellum and amygdala. DNN showed a good area under the curve for cognitive prediction; TICS (0.952), T-MoCA (0.909) and Tele-MACE (0.822). Cognition can be evaluated remotely in which radiotherapy-related brain injury is dose-dependent and volume-dependent. Prediction models can assist in the early identification of patients at risk for neurocognitive decline following RT for glioma, thus facilitating potential treatment interventions.

Utility of Chinese Versions of Addenbrooke's Cognitive Examination: A Narrative Review.

Addenbrooke’s cognitive examination (ACE) is a cognitive screening tool that has developed through three stages: ACE, ACE-Revised (ACE-R), and ACE-Ⅲ. In addition, mini-Addenbrooke’s Cognitive Examination (M-ACE) and ACE mobile are the additional versions that is derived from ACE-III. ACE and its related versions show better performance than Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) in detecting mild cognitive impairment in different neurological disorders. It has been translated into numerous languages, including Chinese. Through reviewing the history, validity, and comparison with other cognitive tests of Chinese versions of ACE, it aims to facilitate the clinical and scientific use, further development, improvement, and validation of Chinese versions of ACE in various neurological disorders and ultimately promote early identification and management of cognitive impairment in China.

Applying ACE-III, M-ACE and MMSE to Diagnostic Screening Assessment of Cognitive Functions within the Polish Population.

The research aims to compare the accuracy of the mini-mental state examination (MMSE), the Addenbrooke’s cognitive examination III (ACE-III) and the mini-Addenbrooke’s cognitive examination (M-ACE) within the Polish population. The model comprised several stages: the features of each test were compared; the shifts in result categorisations between the norm and below the norm were analysed; a third category—mild cognitive impairment (MCI)—was included. Additionally, particular ACE-III domains that scored below domain-specific norm thresholds were analysed to establish the potential early predictors of dementia. All tests correlated to a high and very high degree—cf. MMSE and ACE-III (r = 0.817; p < 0.001), MMSE and M-ACE (r = 0.753; p < 0.001), ACE-III and M-ACE (r = 0.942; p < 0.001). The area under the ROC curve for the ACE-III diagnostic variable had a high value (AUC = 0.920 ± 0.014). A cut-off point of 81 points was suggested for ACE-III; the M-ACE diagnostic variable had an equally high value (AUC = 0.891 ± 0.017). A cut-off point of 20 points was suggested. A significant decrease in the mean score values for people who scored norm or below the norm under ACE-III, as compared to the MMSE results for norm (p < 0.0001), occurred for speech fluency (which decreased by 26.4%). The tests in question are characterised by high sensitivity and specificity. Targeted ACE-III seems best recommended for use in specialised diagnostic centres, whereas M-ACE appears to be a better suited diagnostic alternative for primary health care centres in comparison to MMSE.

Evaluating binary classifiers: extending the Efficiency Index.

Aim: To further develop an 'efficiency index' (EI), the ratio of classifier accuracy to inaccuracy, to construct balanced EI (BEI) and unbiased EI (UEI) measures to evaluate a dementia screening test. EI formulations were compared with cognate formulations of the identification index (II). Materials & methods: A prospective pragmatic test accuracy study dataset examining Mini-Addenbrooke's Cognitive Examination (MACE) was used. Results: EI, BEI and UEI varied with test cutoff. UEI was the most stringent measure, correcting for both disease prevalence and test threshold. Unlike II formulations, the boundary values of EI formulations (0,∞) ensure that negative values never occur. Conclusion: EI metrics may be useful for the evaluation of cognitive screening instruments and other diagnostic tests used for neurodegenerative disorders.

Screening Accuracy of Mini Addenbrooke's Cognitive Examination Test for HIV-Associated Neurocognitive Disorders in People Ageing with HIV.

Aging and increased cardiovascular risk are major drivers for HIV-associated neurocognitive disorders (HAND), for which accurate screenings are lacking. Mini-Addenbrooke's Cognitive Examination (MACE) reliably detects vascular and neurodegenerative cognitive decline among HIV-negative patients. We evaluated MACE diagnostic accuracy in detecting HAND in people living with HIV (PLWH) and we compared it with the International HIV Dementia Scale (IHDS). A single-centre double-blind study of diagnostic accuracy on adult outpatient PLWH without neurocognitive confounding was performed. MACE and IHDS were administered in 5 and 10min by clinicians, followed by the reference standard battery (14 tests) by neuropsychologists. HAND diagnosis was based on the modified version of Frascati's criteria by Gisslén to reduce false positives. Exploratory cut-offs were evaluated for MACE. Diagnostic accuracy and clinical utility parameters were assessed. 231 patients were enrolled. 75.7% men with a median age, education, and length of infection of 54 (48-59), 10 (8-13) and 16 (5-25) years. HAND prevalence was 48.5% (38.9% asymptomatic impairment). Compared to IHDS, MACE sensitivity (89.3% vs 70.5%), specificity (94.1% vs 63.0%), correct classification rate (86.5% vs 66.7%), J index (0.83 vs 0.34), AUROC (0.97 vs 0.79), agreement with the gold standard (k 0.84 vs 0.33) and effect size in distinguishing HAND vs non-HAND (d 2.11 vs 1.15) were higher. Among PLWH aged 65years and above (n = 37) MACE performance was consistently better than IHDS. The quick and easy-to-perform MACE could possess an accurate and useful screening performance for HAND in otherwise neurocognitively healthy cohorts of PLWH.

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

BackgroundFor 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.MethodsA 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.ResultsFive 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.ConclusionIn 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.

Communicating Risk: Developing an "Efficiency Index" for Dementia Screening Tests.

Diagnostic and screening tests may have risks such as misdiagnosis, as well as the potential benefits of correct diagnosis. Effective communication of this risk to both clinicians and patients can be problematic. The purpose of this study was to develop a metric called the “efficiency index” (EI), defined as the ratio of test accuracy and inaccuracy, to evaluate screening tests for dementia. This measure was compared with a previously described “likelihood to be diagnosed or misdiagnosed” (LDM), also based on “numbers needed” metrics. Datasets from prospective pragmatic test accuracy studies examining four brief cognitive screening instruments (Mini-Mental State Examination; Montreal Cognitive Assessment; Mini-Addenbrooke’s Cognitive Examination (MACE); and Free-Cog) were analysed to calculate values for EI and LDM, and to examine their variation with test cut-off for MACE and dementia prevalence. EI values were also calculated using a modification of McGee’s heuristic for the simplification of likelihood ratios to estimate percentage change in diagnostic probability. The findings indicate that EI is easier to calculate than LDM and, unlike LDM, may be classified either qualitatively or quantitatively in a manner similar to likelihood ratios. EI shows the utility or inutility of diagnostic and screening tests, illustrating the inevitable trade-off between diagnosis and misdiagnosis. It may be a useful metric to communicate risk in a way that is easily intelligible for both clinicians and patients.

Receiver operating characteristic plot and area under the curve with binary classifiers: pragmatic analysis of cognitive screening instruments.

Aim: To examine whether receiver operating characteristic plots and area under the curve (AUC) values may be potentially misleading when assessing cognitive screening instruments as binary predictors rather than as categorical or continuous scales. Materials & methods: AUC was calculated using different methods (rank-sum, diagnostic odds ratio) using data from test accuracy studies of two binary classifiers of cognitive status (applause sign, attended with sign), a screener producing categorical data (Codex), and a continuous scale screening test (Mini-Addenbrooke's Cognitive Examination). Results: For all screeners, AUC calculated using diagnostic odds ratio method was greater than using rank-sum method. When Codex and Mini-Addenbrooke's Cognitive Examination were analyzed as binary (single fixed threshold) tests, AUC using rank-sum method was lower than when screeners were analyzed as categorical or continuous scales, respectively. Conclusion: If cognitive screeners producing categorical or continuous measures are dichotomized, calculated AUC may be an underestimate, thus affecting screening test accuracy.

Normative data of the Portuguese version of the Mini-Addenbrooke's Cognitive Examination.

Introduction:Mini-Addenbrooke's Cognitive Examination (M-ACE) is a screening neurocognitive test with diagnostic accuracy for mild cognitive impairment and dementia. The present study aims to determine the construct validity, concurrent and divergent validity and to determine the normative equation for the Portuguese version of M-ACE.Method:The sample is composed by 130 participants without any subjective complaint of memory loss and completely independent in daily life activities, recruited in health units, day care centers and religious and civic associations, from several districts of Portugal. The ACE-III, from which the M-ACE was extracted, and the Geriatric Depression Scale (GDS) were administered to all participants.Results:Reliability is considered good (α = 0.844) and the item-total correlations of the M-ACE were highly significant. M-ACE showed a positive correlation with ACE-III and a negative correlation with GDS. Schooling and age were the only variables related to M-ACE performance. The obtained model from the multiple regression was significant. A normative equation was extracted from this model.Conclusions:The Portuguese version of M-ACE has solid psychometric properties enabling its clinical use. The availability of M-ACE normative equation based on a healthy sample according to age and education enables the use of a brief screening tool for cognitive functioning. M-ACE does not require formal specialized training, it is a quick test which can be an advantage, for instance, in primary health care consultations.

Cognitive testing in the COVID-19 era: can existing screeners be adapted for telephone use?

Aim: To examine whether two existing cognitive screeners might be adapted for telephone administration by omission of item content requiring visual cues or assessment. Materials & methods: Data from a test accuracy study of Mini-Addenbrooke’s Cognitive Examination (MACE) and Free-Cog were used to derive scores for ‘Tele-MACE’ and ‘Tele-Free-Cog’. Results: As in the index study, both Tele-MACE and Tele-Free-Cog proved sensitive for dementia diagnosis. Tele-MACE had a better balance of sensitivity and specificity than observed with MACE. Tele-MACE was sensitive for mild cognitive impairment diagnosis, whereas Tele-Free-Cog was more specific for mild cognitive impairment. Conclusion: Existing cognitive screeners may be adapted for telephone administration. Such developments may prove necessary in the COVID-19 era as remote rather than face-to-face cognitive assessment increasingly becomes the established norm.

A Comparison of the Greek ACE-III, M-ACE, ACE-R, MMSE, and ECAS in the Assessment and Identification of Alzheimer's Disease.

This study aimed to adapt the Addenbrooke's Cognitive Examination-III (ACE-III) and Mini-Addenbrooke's Cognitive Examination (M-ACE) into Greek and then to examine the convergent validity against their predecessors Addenbrooke's Cognitive Examination-Revised (ACE-R) and Mini-Mental State Examination (MMSE) in a Greek population. Moreover, a primary aim was to appraise the utility of each screen by conducting a comparison of the psychometric properties of ACE-III, M-ACE, ACE-R, MMSE, and the Edinburgh Cognitive and Behavioural Amyotrophic Lateral Sclerosis (ALS) Screen (ECAS) in detecting Alzheimer's disease (AD). Forty patients with AD were recruited and matched with 38 controls. Bayesian Pearson's correlation analysis was conducted to examine the convergent validity. Receiver operating characteristic curve analysis was implemented to appraise the sensitivity and specificity of the tests in detecting AD. The ACE-III, M-ACE, and the ECAS scores robustly correlated with ACE-R and MMSE. The ACE-III and the ECAS-ALS Non-Specific score were the most sensitive and specific tools in detecting AD, closely followed by ECAS Total score and M-ACE. Only ECAS Total score correlated with the duration of disease. The ECAS scores were more resilient to ceiling effects than the other screens. M-ACE produced fewer ceiling effects than MMSE. The Greek ACE-III and M-ACE were successfully adapted and showed good convergent validity against their predecessors. They showed very good psychometric properties in detecting AD and may be considered in hectic clinical settings. ECAS Total score and ECAS-ALS Non-Specific showed comparable psychometric properties in the detection of AD and may be considered in polypathological clinics where motor impairments are common.

Mini-Addenbrooke's Cognitive Examination (MACE): a Useful Cognitive Screening Instrument in Older People?

BackgroundThe Mini-Addenbrooke’s Cognitive Examination (MACE) is a recently described brief cognitive screening instrument.ObjectiveTo examine the test accuracy of MACE for the identification of dementia and mild cognitive impairment (MCI) in a cohort of older patients assessed in a neurology-led dedicated cognitive disorders clinic.MethodsCross-sectional assessment of consecutive patients with MACE was performed independent of the reference standard diagnosis based on clinical interview of patient and, where possible, informant and structural brain imaging, and applying standard clinical diagnostic criteria for dementia and MCI. Various test accuracy metrics were examined at two MACE cut-offs ( ≤ 25/30 and ≤ 21/30), comparing the whole patient cohort with those aged ≥ 65 or ≥ 75 years, hence at different disease prevalences.ResultsDependent upon the chosen cut-off, MACE was either very sensitive or very specific for the identification of any cognitive impairment in the older patient cohorts with increased disease prevalence. However, at both cut-offs the positive predictive values and post-test odds increased in the older patient cohorts. At the more sensitive cut-off, improvements in some new unitary test metrics were also seen.ConclusionMACE is a valid instrument for identification of cognitive impairment in older people. Test accuracy metrics may differ with disease prevalence.

Applying Kraemer’s Q (Positive Sign Rate): Some Implications for Diagnostic Test Accuracy Study Results

Background/Aims: Sensitivity and specificity (Sens, Spec) are not invariant properties of diagnostic and screening tests, but vary in different patient samples. Kraemer [Evaluating medical tests. Objective and quantitative guidelines. 1992] used the level of test, Q, also known as “positive sign rate” (sum of true and false positives divided by sample size), to calculate quality sensitivity and specificity (QSN, QSP). These scaled indices may be more comparable across different patient samples, but have been little studied hitherto. Methods: The dataset of a pragmatic test accuracy study of the Mini-Addenbrooke’s Cognitive Examination (MACE) was re-interrogated to calculate values of QSN and QSP and other paired and unitary test outcome measures based on them, and comparison was made with outcomes previously calculated by standard methods. Results: QSN and QSP values in this cohort (n = 755; overall prevalence of dementia and mild cognitive impairment [MCI] 0.15 and 0.29, respectively) were inferior to Sens and Spec, as were all other outcome measures for MACE for the diagnosis of both dementia and MCI. QSN was relatively preserved, indicating the sensitivity of MACE. Conclusion: Indices of test outcome scaled according to Kraemer’s Q, the positive sign rate, are less impressive than outcomes calculated by standard methods. These discrepancies may have implications for test evaluation.

Diagnostic Utility of the Portuguese Version of the Mini-Addenbrooke’s Cognitive Examination in Early Dementia

Abstract. Aims: This contribution studies the psychometric properties (reliability, concurrent validity, and sensitivity) of the Portuguese version of the Mini-Addenbrooke’s Cognitive Examination (M-ACE) in the context of early dementia. Methods: A sample of 60 participants was distributed in two groups: control group and dementia group. The following tests were administered: the ACE-III, from which the M-ACE was extracted, the Clinical Dementia Rating (CDR), and the Montreal Cognitive Assessment (MoCA). The CDR was used to determine the severity of dementia; the MoCA and ACE-III were used to determine the convergent validity of the M-ACE. Results: The reliability of the M-ACE is acceptable (α = .784). We extracted the cut-off scores and the corresponding values of sensitivity and specificity: A cutoff score of 17 on M-ACE has a sensitivity of 100% and specificity of 72.1%. The M-ACE correlated significantly with the ACE-III and the Montreal Cognitive Assessment. Conclusion: The Portuguese version of the M-ACE has satisfactory psychometric characteristics and is a useful screening tool in the context of early dementia. The M-ACE can be employed in primary healthcare consultations.

What is test accuracy? Comparing unitary accuracy metrics for cognitive screening instruments.

Aim: To examine four different accuracy metrics for assessment of commonly used cognitive screening instruments: correct classification accuracy, area under the receiver operating characteristic curve, F measure (F) or F1 score and Matthews correlation coefficient (MCC). Methods: Raw data were extracted from test accuracy studies of Mini-Mental State Examination. Montreal Cognitive Assessment, Mini-Addenbrooke's Cognitive Examination, Six-item Cognitive Impairment Test, informant AD8 and Free-Cog, and used to calculate the accuracy measures. Results: Each metric resulted in similar ordering of the screening instruments for diagnosis of both dementia and mild cognitive impairment. Area under the receiver operating characteristic curve gave the highest (most optimistic) and MCC the lowest (most pessimistic) accuracy value for each test examined, with correct classification accuracy and F falling between. Conclusion: All the accuracy measures examined have potential shortcomings. None can be recommended as the definitive unitary outcome measure for test accuracy studies. However, MCC has theoretical advantages and might be more widely adopted.