Clock Drawing Test Scoring Research Articles

Attentive pairwise interaction network for AI-assisted clock drawing test assessment of early visuospatial deficits

Dementia is a debilitating neurological condition which impairs the cognitive function and the ability to take care of oneself. The Clock Drawing Test (CDT) is widely used to detect dementia, but differentiating normal from borderline cases requires years of clinical experience. Misclassifying mild abnormal as normal will delay the chance to investigate for potential reversible causes or slow down the progression. To help address this issue, we propose an automatic CDT scoring system that adopts Attentive Pairwise Interaction Network (API-Net), a fine-grained deep learning model that is designed to distinguish visually similar images. Inspired by how humans often learn to recognize different objects by looking at two images side-by-side, API-Net is optimized using image pairs in a contrastive manner, as opposed to standard supervised learning, which optimizes a model using individual images. In this study, we extend API-Net to infer Shulman CDT scores from a dataset of 3108 subjects. We compare the performance of API-Net to that of convolutional neural networks: VGG16, ResNet-152, and DenseNet-121. The best API-Net achieves an F1-score of 0.79, which is a 3% absolute improvement over ResNet-152’s F1-score of 0.76. The code for API-Net and the dataset used have been made available at https://github.com/cccnlab/CDT-API-Network.

THE EFFECT OF DURATION OF ACETYLCHOLINE-ESTERASE INHIBITOR ON MMSE, CDT AND BARTHEL INDEX SCORING ON PATIENTS WITH VASCULAR DEMENSIA

Background: Vascular dementia is a cognitive decline with functional deterioration caused by cerebrovascular disease. It is the second leading cause of dementia. A number of screening questionnaires and models have been developed to help in assessing cognitive function and activity daily living (ADL) in patients with dementia. Mini Mental State Examination (MMSE), Clock Drawing Test (CDT) and Barthel Index are instruments to evaluate cognitive function and ADL of vascular dementia patients. Objective: To determine the role of achetylcholine-esterase inhibitor therapy on cognitive function and ADL in patients with vascular dementia in Saiful Anwar General Hospital. Methods: This study is an analytical study assessing the improvement of cognitive function and ADL of patients with vascular dementia after administration of acethylcholine-esterase inhibitor by assessing the MMSE, CDT and Barthel Index scoring in 1, 3, 6 and 12 month period consecutively. Results: From 15 study subjects, individuals who have been given treatment for 12 months consecutively have the highest increase in MMSE and CDT whilst for Barthel Index has shown highest improvement in one month period. Conclusion: The administration of acetylcholine-esterase inhibitor drugs has the potential to improve and maintain cognitive function and improve ADL. The limited number of study subjects and the many confounding factors that we did not evaluate were the drawbacks of this study. The results of this study cannot be generalized to all patients with vascular dementia and only apply to 15 patients who were the subjects of this study.

Clock-drawing test: Normative data of three quantitative scoring methods for Chinese-speaking adults in Shijiazhuang City and clinical utility in patients with acute ischemic stroke.

ObjectiveThe clock‐drawing test (CDT) is a widely used screening tool for detecting cognitive decline. However, normative data for Chinese individuals are scarce. Our study aimed to provide standardized values for the three quantitative CDT scoring methods that were tailored for Chinese‐speaking adults in Shijiazhuang City and explore the discriminant validity of the CDT scores in patients with acute ischemic stroke.MethodsWe conducted the CDT among 418 healthy individuals aged between 35 and 84 years. The CDT was administered and scored by five raters using the method derived from the Montreal Cognitive Assessment (MoCA), Rouleau's, and Babins’ scoring systems. The influence of age, education, and sex on the performance in the CDT was analyzed. Furthermore, 336 patients with acute ischemic stroke were enrolled to explore the discriminant validity of CDT scores.ResultsIn all three scoring systems, CDT scores were significantly correlated with age and years of education but not with sex. Normative data stratified for age and years of education were established. Interrater and intersystem reliability were high in our study. CDT total scores and subscores showed significant differences between stroke patients and healthy individuals.ConclusionsOur study provides CDT normative data using three quantitative scoring methods for Chinese‐speaking adults in Shijiazhuang City. Age and education level were the key factors that affected the CDT scores. CDT total scores and subscores provided good discriminant validity for patients with acute ischemic stroke.

A systematic review and meta-analysis of the accuracy of the clock drawing test (CDT) in the identification of delirium in older hospitalised patients

Objective: Delirium is a common neurocognitive syndrome among hospitalised older adults. The clock drawing test (CDT) is a relatively simple bedside test of cognitive function. This systematic review and meta-analysis examine the accuracy of the CDT in identifying delirium in hospitalised older adults.Methods: PRISMA guidelines were used to report the identified studies. Pubmed, SCOPUS, and Ovid and EBSCO platforms (including MEDLINE ®, PsycINFO, PsycEXTRA, EMCARE, CINAHL and EMBASE databases) were searched. Studies were assessed for methodological quality using the Downs and Black Tool. Data were extracted regarding the number of delirious/not delirious, number with normal and abnormal CDT, age, and MMSE scores, and information regarding CDT scoring, criteria for diagnosis of delirium and setting of the study. Analysis was carried out with the “Mada” and “Metatron” packages of R software.Results: Fifteen studies were examined. The number of participants was 2199, of whom 597 (27.15%) were diagnosed with delirium. The overall sensitivity of CDT in the absence of any formal cognitive test was 0.76 (0.58–0.87) with specificity of 0.70 (0.51–0.83). When the MMSE was taken into account, the specificity and sensitivity reduced to 0.51. Diagnostic criteria for delirium, scoring method of CDT, age of participants and setting significantly (p < 0.05) affect the sensitivity and specificity of the CDT.Conclusion: Although, the CDT is generally considered to be a simple and easy to administer screening tool for cognitive impairment in older hospitalised adults, when a more formal cognitive test is used its sensitivity and specificity to detect delirium is low.

Validation of the Clock Drawing Test Scoring Method in older adults with neurocognitive disorder

Introduction. The Clock Drawing Test (CDT) is a widely used instrument for identifying neurocognitive disorders (NCDs) in older adults. However, there is insufficient evidence to determine the best scoring method, since current quantitative methods involve the assignment of numerical values, while qualitative ones do not allow for objectivity in the diagnosis. Parsey and Schmitter-Edgecombe (2011) proposed a scoring scheme which, in addition to providing a score of the patient’s performance, permits error analysis, thereby making it possible to identify potential underlying cognitive difficulties. Objective. The purpose of this study was to validate the CDT scoring scheme proposed by Parsey and Schmitter-Edgecombe (2011) for screening for NCDs in Mexican older adults. Method. There were 167 participants: 58 cognitively healthy subjects (CH), 52 with mild neurocognitive disorder (mild-NCD), and 57 with major neurocognitive disorder (major-NCD).The CDT scoring method was compared with the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment in Spanish (MoCA-S). Inter- and intra-observer reliability and construct validity were determined and the sensitivity and specificity of this method were calculated. Results. The  age was 75 years (SD ± 8 years) and the  educational attainment was 10.7 years (SD ± 5.2 years). Internal reliability was .750, with an intraclass correlation coefficient of .774. The cut-off point for the CDT in mild-NCD was 14 points (sensitivity: 40%, specificity: 70%) and 12 points for major-NCD (sensitivity: 90%, specificity: 95%).The most frequent errors in the CDT were: graphic, conceptual, spatial, and/or planning difficulties. Discussion and conclusion. This method makes it possibly to quickly and easily explore the cognitive status of the patient. It contains ideal psychometric properties for the detection of patients with major-NCD, in addition to offering the possibility of analyzing performance errors and underlying cognitive difficulties.

Clock Drawing Test: A Simple Scoring System for the Accurate Screening of Cognitive Impairment in Patients with Mild Cognitive Impairment and Dementia

Background/Aim: The Clock Drawing Test (CDT) is a valid alternative screening tool to the Mini-Mental State Examination (MMSE) and, crucially, it may be completed faster. The aim of our study was to standardize and simplify the CDT scoring system for screening in three common conditions: mild cognitive impairment (MCI), Alzheimer’s disease (AD) and mixed dementia (MD). Methods: We included 188 subjects (43 healthy volunteers, 49 patients with MCI, 54 patients with AD, and 42 patients with MD), who performed the MMSE and CDT. The CDT was evaluated using a modified 4-point scoring system. Results: The healthy subjects had the highest median values for the MMSE and CDT, followed by patients with MCI, AD and MD. The optimal cut-off for all patients and each patient group separately was 3 out of 4 points. Sensitivity was 89% for AD, 93% for MD and 83% for all patients, while specificity was 91%. The MMSE produced similar results. In comparison to the MMSE, sensitivity for MCI was significantly higher using the CDT (20 vs. 69%, respectively). Conclusion: A simple, 4-point scoring system may be used as a screening method for fast and accurate detection of cognitive impairment in patients with MCI, AD and MD.

Clock Drawing Test in acute stroke and its relationship with long-term functional and cognitive outcomes

Objective: The Clock Drawing Test (CDT) is commonly used as a screening tool for the assessment of dementia. The association between the CDT in acute stroke and long-term functional and cognitive outcomes in this population is unknown. The present prospective study is the first to examine if CDT scores in the acute stage after stroke are related to long-term outcomes and to compare the predictive ability of two scoring systems in a large sample of stroke patients. Method: A total of 340 patients admitted to an acute stroke unit were included in the present study. Separate stepwise multiple linear regression analyses were performed with eight independent variables (demographic/pre-stroke variables – age, sex, premorbid functioning; stroke-related variables – stroke severity, localization; cognitive variables – Orientation Test, CDT [2 scoring systems]), and four dependent variables administered one year post-stroke (Barthel Index, modified Rankin Scale, Reintegration to Normal Living index, Global Deterioration Scale). Results: Although both CDT scoring methods were related to all long-term outcome measures, the more comprehensive scoring system was the only baseline variable that significantly explained the variance in outcome measures in all four multiple regression models. Conclusion: Performance on the CDT in acute stroke is related to long-term outcomes including patients’ degree of independence in performing activities of daily living, the degree to which they achieved reintegration into daily occupations, and the degree of cognitive decline observed one-year post-stroke. Future studies are needed to clarify the nature of the relationship between different CDT scoring systems and post-stroke outcomes.

Validity and Clinical Utility of Different Clock Drawing Test Scoring Systems in Multiple Forms of Dementia.

The Clock Drawing Test (CDT) has a known potential for the detection of cognitive impairment in populations with dementia, especially Alzheimer disease (AD). Our aim was to compare the clinical utility of 3 CDT scoring systems (Rouleau, Cahn, and Babins) in several pathologies with cognitive compromise from a tertiary center memory clinic. We selected patients with a clinical diagnosis of mild stage AD, behavioral variant frontotemporal dementia (FTD), vascular dementia (VaD), dementia with Lewy bodies (DLB), and Parkinson disease with dementia (PDD). The results showed significant differences between the several diagnoses with the following pattern of results: AD, DLB < FTD, VaD, PDD. Qualitative analysis of clock drawing errors confirmed the stimulus-bound response as a hallmark of AD, while conceptual deficit was significantly more prevalent in patients with AD and DLB. Our results supported the CDT potential as a cognitive screening measure for mild dementia, particularly sensitive to AD and DLB, especially when we used the Cahn scoring system and its analysis of qualitative errors.

The Reliability of Clock Drawing Test Scoring Systems Modeled on the Normative Data in Healthy Aging and Nonamnestic Mild Cognitive Impairment.

The Clock Drawing Test (CDT) is a commonly used tool in clinical practice and research for cognitive screening among older adults. The main goal of the present study was to analyze the interrater reliability of three different CDT scoring systems (by Shulman et al., Babins et al., and Cohen et al.). We used a clock with a predrawn circle. The CDT was evaluated by three independent raters based on the normative data set of healthy older and very old adults and patients with nonamnestic mild cognitive impairment (naMCI; N = 438; aged 61-94). We confirmed a high interrater reliability measured by the intraclass correlation coefficients (ICCs): Shulman ICC = .809, Babins ICC = .894, and Cohen ICC = .862, all p < .001. We found that age and education levels have a significant effect on CDT performance, yet there was no influence of gender. Finally, the scoring systems differentiated between naMCI and age- and education-matched controls: Shulman's area under the receiver operating characteristic curve (AUC) = .84, Cohen AUC = .71, all p < .001; and a slightly lower discriminative ability was shown by Babins: AUC = .65, p = .012.

C-59Exploring the Validity of a Computerized Clock Drawing Test Scoring System in a Mixed Clinical Sample

C-59Exploring the Validity of a Computerized Clock Drawing Test Scoring System in a Mixed Clinical Sample

The use of the Clock Drawing Test in bipolar disorder with or without dementia of Alzheimer's type.

There is limited data regarding the cognitive profile from screening tests of older adults with bipolar disorder (BD) with dementia. Objective To investigate the Clock Drawing Test (CDT) among older adults with BD with and without Alzheimer's disease (AD). Method 209 older adults (79 with BD without dementia and 70 controls; 60 with AD, being 27 with BD) were included to evaluate the performance of three CDT scoring scales, beyond the Mini-Mental State Examination (MMSE) and verbal fluency (VFT). Results Patients with BD without dementia presented with lower scores in MMSE, VF and one CDT scoring scale than controls. Patients with BD and AD presented with lower scores in VF and CDT scoring scales than patients with only AD. All CDT scales presented similar sensitivity and specificity for BD and non-BD groups. Conclusion Elderly subjects with BD showed greater impairment in CDT in both groups of normal cognition and AD.

Clock Drawing Test and the diagnosis of amnestic mild cognitive impairment: Can more detailed scoring systems do the work?

Introduction: The Clock Drawing Test is a frequently used cognitive screening test with several scoring systems in elderly populations. We compare simple and complex scoring systems and evaluate the usefulness of the combination of the Clock Drawing Test with the Mini-Mental State Examination to detect patients with mild cognitive impairment. Method: Patients with amnestic mild cognitive impairment (n = 48) and age- and education-matched controls (n = 48) underwent neuropsychological examinations, including the Clock Drawing Test and the Mini-Mental State Examination. Clock drawings were scored by three blinded raters using one simple (6-point scale) and two complex (17- and 18-point scales) systems. The sensitivity and specificity of these scoring systems used alone and in combination with the Mini-Mental State Examination were determined. Results: Complex scoring systems, but not the simple scoring system, were significant predictors of the amnestic mild cognitive impairment diagnosis in logistic regression analysis. At equal levels of sensitivity (87.5%), the Mini-Mental State Examination showed higher specificity (31.3%, compared with 12.5% for the 17-point Clock Drawing Test scoring scale). The combination of Clock Drawing Test and Mini-Mental State Examination scores increased the area under the curve (0.72; p < .001) and increased specificity (43.8%), but did not increase sensitivity, which remained high (85.4%). Conclusions: A simple 6-point scoring system for the Clock Drawing Test did not differentiate between healthy elderly and patients with amnestic mild cognitive impairment in our sample. Complex scoring systems were slightly more efficient, yet still were characterized by high rates of false-positive results. We found psychometric improvement using combined scores from the Mini-Mental State Examination and the Clock Drawing Test when complex scoring systems were used. The results of this study support the benefit of using combined scores from simple methods.

Longitudinal changes in clock drawing test (CDT) performance before and after cognitive decline.

BackgroundMany scoring systems exist for clock drawing task variants. However, none of them are reliable in evaluating longitudinal changes of cognitive function. The purpose of this study is to create a simple yet optimal scoring procedure to evaluate cognitive decline using a clinic-based sample.MethodsClock-drawings from 121 participants (76 individuals with no dementia and later did not develop dementia after a mean 41.2-month follow-up, 45 individuals with no dementia became demented after a mean 42.3-month follow-up) were analyzed using t-test to determine a new and simplified CDT scoring system. The new scoring method was then compared with other commonly used systems.ResultsIn the converters, there were only 7 items that are significantly different between the initial visits and the second visits. We propose a new scoring system that includes the seven critical items: numbers are equally spaced (12–3–6–9) (p = 0.031), the other eight numbers are marked (p = 0.022), numbers are clockwise (p = 0.002), all numbers are correct (p = 0.030), distance between numbers is constant (p = 0.016), clock has two hands (p = 0.000), arrows are drawn (p = 0.003). Compared with other traditionally used scoring methods, this based change clock drawing test (BCCDT) has one of the most balanced sensitivities/specificities with a clinic-based sample.ConclusionsThe new CDT scoring system provides further evidence in support of a simple and reliable clock-drawing scoring system in follow-up studies to evaluate cognitive decline, which can be used in assessing the efficacy of medicine.

A reduced scoring system for the Clock Drawing Test using a population-based sample

Many scoring systems exist for clock drawing task variants, which are common dementia screening measures, but all have been derived from clinical samples. This study evaluates and combines errors from two published scoring systems for the Clock Drawing Test (CDT), the Lessig and Tuokko methods, in order to create a simple yet optimal scoring procedure to screen for dementia using a Canadian population-based sample. Clock-drawings from 356 participants (80 with dementia, 276 healthy controls) from the Canadian Study on Health and Aging were analyzed using logistic regression and Receiver Operating Characteristic curves to determine a new, simplified, population-based CDT scoring system. The new Jouk scoring method was then compared to other commonly used systems (e.g. Shulman, Tuokko, Watson, Wolf-Klein). The Jouk scoring system reduced the Lessig system even further to include five critical errors: missing numbers, repeated numbers, number orientation, extra marks, and number distance, and produced a sensitivity of 81% and a specificity of 68% with a cut-off score of one error. With regard to other traditionally used scoring methods, the Jouk procedure had one of the most balanced sensitivities/specificities when using a population-based sample. The results from this study improve our current state of knowledge concerning the CDT by validating the simplified scoring system proposed by Lessig and her colleagues in a more representative sample to mimic conditions a general clinician or researcher will encounter when working among a wide-ranging population and not a dementia/memory clinic. The Jouk CDT scoring system provides further evidence in support of a simple and reliable dementia-screening tool that can be used by clinicians and researchers alike.

Clock Drawing Test – screening utility for mild cognitive impairment according to different scoring systems: results of the Leipzig Longitudinal Study of the Aged (LEILA 75+)

There is a strong demand for screening instruments for mild cognitive impairment (MCI), as a pre-stage of dementia. The clock drawing test (CDT) is widely used to screen for dementia, but the utility in screening for MCI remains uncertain. In particular, it is still questionable which scoring system is the best in order to screen for MCI. We therefore aimed to compare the utility of different CDT scoring systems for screening for MCI. In a sample of 428 subjects of the Leipzig Longitudinal Study of the Aged (LEILA 75+) study, CDT scores of different scoring systems were compared between subjects with and without MCI. Comparison of receiver operating characteristic (ROC; area under the curve, sensitivity, specificity) was performed and inter-rater reliability was calculated. The CDT scores differed significantly between MCI and non-MCI subjects according to all scoring systems applied. However, ROC of the CDT scores was not adequate. None of the present CDT scoring systems has sufficient utility to screen reliably for MCI. The clinical value of the CDT could be improved by using semi-quantitative scoring, having a wider score range and focusing on specific details of the clock (e.g. the hands and numbers).

Does the Clock Drawing Test predict dementia? Results of the Leipzig Longitudinal Study of the Aged (LEILA 75+)

Background/Objectives: Being diagnosed with dementia has an enormous impact on the patients themselves as well as on caregivers and the society. Therefore research aims to identify individuals at risk prior to a diagnosis of dementia in order to maximise preventive and treatment efficacy. In recent years, research on the preclinical detection of dementia focused on the concept of mild cognitive impairment (MCI), a transitional phase between normal aging and dementia. Patients diagnosed with MCI are more likely to develop dementia compared to normal control groups and therefore represent a high-risk group. However, establishing a diagnosis of MCI often is time consuming. The Clock Drawing-Test (CDT) has been widely used to screen for dementia, especially because of its easy, quick and simple administration and good acceptance among elderly patients. Nonetheless, it is still questionable whether the CDT is an appropriate instrument to identify persons at an early stage or at a high risk of onset of dementia. Methods: Data were derived from the Leipzig Longitudinal Study of the Aged (LEILA 75+), a population-based study of individuals aged 75 and over. In this study the CDT version of Shulman et al. was used. MCI was diagnosed according to the international consensus criteria of Winblad. The cognitive criteria for a dementia diagnosis were based on the „Structured Interview for the Diagnosis of Dementia of Alzheimer type, Multi-infarct Dementia and Dementia of other Etiology according to DSM-III-R, DSM-IV and ICD-10“ (SIDAM) or, with proxy interviews, on the „Clinical Dementia Rating Scale“ (CDR). The CDT scores and diagnosis of MCI between patients developing and patients not developing dementia were compared. Multivariate analyses (Cox proportional hazard models, Kaplan-Meier), receiver operating characteristic analyses, and sensitivity and specificity of the CDT were calculated. Results: A total of 7.3% subjects of the initial population were diagnosed with dementia at the following assessment, on average 1.4 years after the initial assessment. Individuals developing dementia at follow-up more often had an initial diagnosis of MCI (64.3% vs. 9.3%) and showed significantly higher CDT scores (2.64 vs. 1.82) compared to those not developing dementia during the study course. The results of the multivariate analysis also revealed that CDT and MCI had a significant effect on a future diagnosis of dementia after adjusting for different confounding variables. The area under the curve was 0.700 (p<0.001) for predicting dementia by using the CDT, and 0.775 (p<0.001) by using MCI-diagnosis. According to the best ratio of values of sensitivity and specificity, the best cut off point was at a CDT score of 3 points. However, the values of sensitivity (67.9%) and specificity (65.2%) were not adequate for predicting a diagnosis of dementia. Discussion/Conclusions: The Clock Drawing Test significantly differentiated between patients developing dementia and patients not developing dementia during the course of the study. Although our results indicate that a diagnosis of MCI is slightly better in predicting dementia than the CDT, the quality of prediction is insufficient for both. While diagnosing MCI is very time consuming, the CDT's major qualities are its quick application and scoring. Further research should therefore aim at improving the CDT scoring system which should focus in more detail on the placement and the size of the hands in order to increase predictive validity. Funding: German Federal Ministry of Education and Research (grant no. 01 ET 0728), and Interdisciplinary Research Cluster of Genetic Factors, Clinical Phenotypes and Environment (LIFE Centre, University of Leipzig). Keywords: Outcome assessment, Clock Drawing Test, dementia.

Does the Clock Drawing Test Predict Dementia? Results of the Leipzig Longitudinal Study of the Aged (LEILA 75+)

Background/Aims: Conversion rates to dementia are known to be high for patients with mild cognitive impairment (MCI), but the diagnosis of MCI is very time-consuming. Since the Clock Drawing Test (CDT) is quick to administer, it will be of interest to compare the predictive validity of the CDT and of an MCI diagnosis for the diagnosis of dementia. Methods: In a sample of 384 individuals, CDT scores and the presence of MCI were assessed at baseline and then compared between individuals with an incident dementia diagnosis at follow-up and those without. Multivariate analyses, receiver operating characteristic analyses and values of sensitivity and specificity of the CDT were performed. Results: Individuals with incident dementia had significantly higher CDT scores at baseline than those without dementia. CDT was a significant predictor of incident dementia after adjusting for other factors. CDT reached a sensitivity of 68% and specificity of 65%. The area under the receiver operating characteristic curve of CDT was 0.70 and therefore slightly lower than for MCI diagnosis (0.78). Conclusions: Because of the only slightly lower predictive value of the CDT, its quick application and scoring compared to the MCI concept applied, it will be worthwhile to improve the CDT scoring system in order to increase the predictive validity in dementia.

Neural correlates of performance on the different scoring systems of the clock drawing test

The aim of this study was to identify brain regions associated with performance on various measures of the clock drawing test (CDT) using magnetic resonance imaging (MRI).We recruited 48 participants (four healthy, eight with mild cognitive impairment and 36 with Alzheimer's disease). Multiple regression analyses identified relationships between each CDT scoring system (Shulman CDT, Rouleau CDT and CLOX1) and regional gray matter (GM) volume.CDT scores were positively correlated with regional GM volume in the right parietal lobe for all three CDT scoring systems. In addition, CDT scores were positively correlated with regional GM volume in the bilateral posterior temporal lobes for the Shulman CDT, in the right posterior inferior temporal lobe for the Rouleau CDT and in the right posterior superior temporal lobe for the CLOX1.Although the scoring systems share commonalities, each CDT scoring system may reflect different areas of brain damage.

Clock drawing test ratings by dementia specialists: interrater reliability and diagnostic accuracy.

The authors conducted a study of clock drawing test scoring by dementia specialists to determine interrater reliability and diagnostic accuracy. The authors randomly assigned 25 clocks from each of six predetermined groups based on consensus diagnosis (cognitive comparison subjects, subjects with a memory complaint but with normal neuropsychological testing, subjects with probable and possible mild cognitive impairment, and subjects with possible and probable Alzheimer's disease) to dementia specialists for blinded scoring using a binary yes/no impairment system and a 0-10 scale as subjectively determined by each individual clinician rater. The authors collapsed the six groups into three (comparison subjects, mild cognitive impairment patients, and Alzheimer's disease patients) and analyzed interrater reliability, sensitivity, and specificity for consensus diagnosis of mild cognitive impairment and Alzheimer's disease. The authors found excellent interrater reliability, sensitivity, and specificity for predicting consensus diagnosis. The 0-10 clock drawing test rating scale was more predictive of consensus diagnosis than the binary impairment scale. Based on rating systems, clock drawing test scoring by dementia clinicians had excellent interrater reliability and sensitivity for differentiating the mild Alzheimer's disease subjects from comparison subjects.

Is the Clock Drawing Test a screening tool for the diagnosis of mild cognitive impairment? A systematic review

The clock drawing test (CDT) is a common and widely used cognitive screening instrument for the diagnosis of dementia. However, it has remained unclear whether it is a suitable method to identify mild cognitive impairment (MCI). The aim of this paper is to review systematically the studies concerning the utility of the CDT in diagnosing MCI. A systematic literature search was conducted. All studies dealing with utility of CDT in diagnosing MCI regardless of the applied CDT scoring system and MCI concept were selected. Nine relevant studies were identified. The majority of the studies compared average CDT scores of cognitively healthy and mildly impaired subjects, and four of them identified significant mean differences. If reported, sensitivity and specificity have been mostly unsatisfactory. CDT should not be used for MCI-screening.