scholarly journals Mini-Cog versus Codex (cognitive disorders examination) Is there a difference?

2020 ◽  
Vol 14 (2) ◽  
pp. 128-133 ◽  
Author(s):  
Andrew J. Larner

Abstract. Mini-Cog and Codex (cognitive disorders examination) are brief cognitive screening tests incorporating word-recall and clock drawing tests. Objective: To assess and compare the screening accuracy of Mini-Cog and Codex for diagnosis of dementia and mild cognitive impairment (MCI) in patients attending a dedicated cognitive disorders clinic. Methods: Tests were administered to a consecutive cohort of 162 patients, whose reference standard diagnoses based on clinical diagnostic criteria were dementia (44), MCI (26), and subjective memory complaint (92). Results: Both Mini-Cog and Codex had high sensitivity (>0.8) for dementia diagnosis, but Codex was more specific. For diagnosis of MCI, Mini-Cog had better sensitivity than Codex. Weighted comparisons of Mini-Cog and Codex showed only marginal net benefit for Mini-Cog for dementia diagnosis but larger net benefit for MCI diagnosis. Conclusion: In this pragmatic study both Mini-Cog and Codex were accurate brief screening tests for dementia but Mini-Cog was better for identification of MCI.

Diagnostics ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 58 ◽  
Author(s):  
Besa Ziso ◽  
Andrew J. Larner

Many cognitive screening instruments are available to assess patients with cognitive symptoms in whom a diagnosis of dementia or mild cognitive impairment is being considered. Most are quantitative scales with specified cut-off values. In contrast, the cognitive disorders examination or Codex is a two-step decision tree which incorporates components from the Mini-Mental State Examination (MMSE) (three word recall, spatial orientation) along with a simplified clock drawing test to produce categorical outcomes defining the probability of dementia diagnosis and, by implication, directing clinician response (reassurance, monitoring, further investigation, immediate treatment). Codex has been shown to have high sensitivity and specificity for dementia diagnosis but is less sensitive for the diagnosis of mild cognitive impairment (MCI). We examined minor modifications to the Codex decision tree to try to improve its sensitivity for the diagnosis of MCI, based on data extracted from studies of two other cognitive screening instruments, the Montreal Cognitive Assessment and Free-Cog, which are more stringent than MMSE in their tests of delayed recall. Neither modification proved of diagnostic value for mild cognitive impairment. Possible explanations for this failure are considered.


2017 ◽  
Vol 29 (6) ◽  
pp. 931-937 ◽  
Author(s):  
A.J. Larner

ABSTRACTBackground:The Mini-Addenbrooke's Cognitive Examination (MACE) is a new brief cognitive screening instrument for dementia and mild cognitive impairment (MCI). Historical data suggest that MACE may be comparable to the Montreal Cognitive Assessment (MoCA), a well-established cognitive screening instrument, in secondary care settings, but no head-to-head study has been reported hitherto.Methods:A pragmatic diagnostic accuracy study of MACE and MoCA was undertaken in consecutive patients referred over the course of one year to a neurology-led Cognitive Function Clinic, comparing their performance for the diagnosis of dementia and MCI using various test metrics.Results:In a cohort of 260 patients with dementia and MCI prevalence of 17% and 29%, respectively, both MACE and MoCA were quick and easy to use and acceptable to patients. Both tests had high sensitivity (>0.9) and large effect sizes (Cohen's d) for diagnosis of both dementia and MCI but low specificity and positive predictive values. Area under the receiver operating characteristic curve was excellent for dementia diagnosis (both >0.9) but less good for MCI (MoCA good and MACE fair). In contrast, weighted comparison suggested test equivalence for dementia diagnosis but with a slight net benefit for MACE for MCI diagnosis.Conclusions:MACE is an acceptable and accurate test for the assessment of cognitive problems, with performance comparable to MoCA. MACE appears to be a viable alternative to MoCA for testing patients with cognitive complaints in a secondary care setting.


2015 ◽  
Vol 86 (11) ◽  
pp. e4.139-e4
Author(s):  
Andrew Larner

ObjectiveTo test diagnostic accuracy of the mini-Addenbrooke's Cognitive Examination (m-ACE) compared to the MMSE for the diagnosis of dementia and MCI in consecutive referrals to a dedicated cognitive disorders clinic.Results: Of 135 consecutive new outpatients seen over 6 months (June–November 2014) administered the mini-ACE (F:M=64:71, 47% female; age range 18–88 years, median 60), 24 were diagnosed with dementia (DSM–IV–TR criteria) and 39 had MCI (Petersen criteria). Using the cutoffs defined in the index paper (≤25/30 and ≤21/30), m-ACE was sensitive (1.00, 0.92) but not specific (0.28, 0.61) for dementia diagnosis; it also proved useful for MCI diagnosis (sensitivities 1.00, 0.77; specificities 0.43, 0.82). Area under the ROC curve was 0.86. Effect size (Cohen's d) for m-ACE for dementia vs. no dementia was 1.53 (large) and for MCI vs no cognitive impairment was 1.59 (large); for MMSE the corresponding figures were 1.56 and 1.26. Weighted comparison suggested a small net loss for m-ACE vs MMSE for dementia diagnosis (–0.13) but a large net benefit for MCI diagnosis (0.38).Conclusions: In this pragmatic study, m-ACE proved quick, easy to use, and acceptable to patients, with metrics comparable to MMSE for dementia diagnosis and better for MCI diagnosis.


2018 ◽  
Vol 45 (5-6) ◽  
pp. 300-307 ◽  
Author(s):  
John C. Williamson ◽  
Andrew J. Larner

Background/Aims: The Mini-Addenbrooke’s Cognitive Examination (MACE) is a relatively new short cognitive screening instrument for the detection of patients with dementia and mild cognitive impairment (MCI). Few studies of the MACE have been reported hitherto. The aim of this study was to undertake a pragmatic diagnostic test accuracy study of MACE in a large cohort of patients seen in a dedicated cognitive disorders clinic. Methods: MACE was administered to consecutive patients referred to a neurology-led Cognitive Function Clinic over the course of 3 years to assess its performance for the diagnosis of dementia and MCI using various test metrics. Results: In a cohort of 599 patients, the prevalence of dementia and MCI by criterion diagnosis was 0.17 and 0.29, respectively. MACE had a high sensitivity (> 0.9) and negative predictive values (> 0.8) with large effect sizes (Cohen’s d > 1) for the diagnosis of both dementia and MCI but a low specificity (< 0.5) and positive predictive values (≤0.5). Conclusion: MACE is an acceptable test for the assessment of cognitive complaints in a secondary care setting with good metrics for identifying cases of both dementia and MCI.


2015 ◽  
Vol 27 (6) ◽  
pp. 991-997 ◽  
Author(s):  
K. Abdel-Aziz ◽  
A. J. Larner

ABSTRACTBackground:The six-item cognitive impairment test (6CIT) is a brief cognitive screening instrument (CSI) recommended for use in primary care settings. There are very few studies of 6CIT performance in secondary care settings.Methods:We undertook a pragmatic diagnostic accuracy study of 6CIT in consecutive patients referred over the course of one year to a neurology-led cognitive function clinic, and compared its performance for the diagnosis of dementia and mild cognitive impairment (MCI) to that of the simultaneously administered Mini-Mental State Examination (MMSE).Results:In a cohort of 245 patients with dementia prevalence around 20%, 6CIT proved quick and easy to use and acceptable to patients. It had good sensitivity (0.88) and specificity (0.78) for dementia diagnosis; it was more sensitive than MMSE (0.59) but less specific (0.85). For MCI diagnosis, 6CIT was again more sensitive (0.66) than MMSE (0.51) but less specific (0.70 vs. 0.75). Weighted comparisons showed net benefit for 6CIT compared to MMSE for both dementia and MCI diagnosis. 6CIT effect sizes (Cohen's d) were large for dementia diagnosis and moderate for MCI diagnosis.Conclusions:6CIT is an acceptable and accurate test for the assessment of cognitive problems, its performance being more sensitive than the MMSE. 6CIT use should be considered as a viable alternative to MMSE in the secondary care setting.


2019 ◽  
Vol 47 (4-6) ◽  
pp. 254-263 ◽  
Author(s):  
Andrew J. Larner

Background/Aims: Canonical definitions of the dementia construct encompass deficits in both cognition and function, but most screening instruments for possible dementia address only cognitive abilities. Free-Cog is a recently described brief screening instrument for dementia designed to address not only cognitive but also functional abilities. Methods: A pragmatic test accuracy study of Free-Cog was undertaken in consecutive patients seen over 1 year in a secondary care setting. The performance of Free-Cog for diagnosis of dementia and mild cognitive impairment (MCI) was compared to that of Mini-Addenbrooke’s Cognitive Examination (MACE). Results: In a cohort of 141 patients (prevalence of dementia and MCI 11 and 32%, respectively) both Free-Cog and MACE were quick and easy to use and acceptable to patients. Both tests had high sensitivity (1.00) and large effect sizes (Cohen’s d) for diagnosis of dementia, but Free-Cog was more specific. For diagnosis of MCI, Free-Cog lacked sensitivity (0.58) but was specific (0.81), whereas MACE was sensitive (0.91) but not specific (0.35). Weighted comparison suggested equivalence for dementia diagnosis but a net benefit for MACE regarding MCI diagnosis. Conclusion: Free-Cog is an acceptable and accurate test for dementia screening in a dedicated cognitive disorders clinic, but it appears less sensitive than MACE for the identification of MCI.


Diagnostics ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 95 ◽  
Author(s):  
Emma Elliott ◽  
Bogna A. Drozdowska ◽  
Martin Taylor-Rowan ◽  
Robert C. Shaw ◽  
Gillian Cuthbertson ◽  
...  

Full completion of cognitive screening tests can be problematic in the context of a stroke. Our aim was to examine the completion of various brief cognitive screens and explore reasons for untestability. Data were collected from consecutive stroke admissions (May 2016–August 2018). The cognitive assessment was attempted during the first week of admission. Patients were classified as partially untestable (≥1 test item was incomplete) and fully untestable (where assessment was not attempted, and/or no questions answered). We assessed univariate and multivariate associations of test completion with: age (years), sex, stroke severity (National Institutes of Health Stroke Scale (NIHSS)), stroke classification, pre-morbid disability (modified Rankin Scale (mRS)), previous stroke and previous dementia diagnosis. Of 703 patients admitted (mean age: 69.4), 119 (17%) were classified as fully untestable and 58 (8%) were partially untestable. The 4A-test had 100% completion and the clock-draw task had the lowest completion (533/703, 76%). Independent associations with fully untestable status had a higher NIHSS score (odds ratio (OR): 1.18, 95% CI: 1.11–1.26), higher pre-morbid mRS (OR: 1.28, 95% CI: 1.02–1.60) and pre-stroke dementia (OR: 3.35, 95% CI: 1.53–7.32). Overall, a quarter of patients were classified as untestable on the cognitive assessment, with test incompletion related to stroke and non-stroke factors. Clinicians and researchers would benefit from guidance on how to make the best use of incomplete test data.


2016 ◽  
Vol 30 (2) ◽  
pp. 104-108 ◽  
Author(s):  
A. J. Larner

The diagnostic accuracy of the short Montreal Cognitive Assessment (s-MoCA), a cognitive screening instrument recently derived by item response theory and computerized adaptive testing from the original MoCA, for the diagnosis of dementia and mild cognitive impairment (MCI) was assessed in 2 patient cohorts referred to a dedicated memory clinic in order to examine the validity and reproducibility of s-MoCA. Diagnosis used standard clinical diagnostic criteria for dementia and MCI as reference standard (prevalence of cognitive impairment = 0.43 and 0.46 in each cohort, respectively). There were significant differences in s-MoCA test scores for dementia, MCI, and subjective memory impairment ( P ≤ .01), and s-MoCA effect sizes (Cohen d) were medium to large (range: 0.65-1.42) for the diagnosis of dementia and MCI. Using the cut-off for s-MoCA specified in the index study, it proved highly sensitive (>0.9) for diagnosis of dementia but with poor specificity (≤0.25), with moderate sensitivity (≥0.75) and specificity (≥0.60) for diagnosis of MCI. In conclusion, in these pragmatic diagnostic test accuracy studies, s-MoCA proved acceptable and sensitive for the diagnosis of cognitive impairment in a memory clinic setting, with a performance similar to that of the original MoCA.


2021 ◽  
Vol 15 (4) ◽  
pp. 458-463
Author(s):  
Andrew J. Larner

ABSTRACT Cognitive screening instruments (CSIs) for dementia and mild cognitive impairment are usually characterized in terms of measures of discrimination such as sensitivity, specificity, and likelihood ratios, but these CSIs also have limitations. Objective: The aim of this study was to calculate various measures of test limitation for commonly used CSIs, namely, misclassification rate (MR), net harm/net benefit ratio (H/B), and the likelihood to be diagnosed or misdiagnosed (LDM). Methods: Data from several previously reported pragmatic test accuracy studies of CSIs (Mini-Mental State Examination, the Montreal Cognitive Assessment, Mini-Addenbrooke’s Cognitive Examination, Six-item Cognitive Impairment Test, informant Ascertain Dementia 8, Test Your Memory test, and Free-Cog) undertaken in a single clinic were reanalyzed to calculate and compare MR, H/B, and the LDM for each test. Results: Some CSIs with very high sensitivity but low specificity for dementia fared poorly on measures of limitation, with high MRs, low H/B, and low LDM; some had likelihoods favoring misdiagnosis over diagnosis. Tests with a better balance of sensitivity and specificity fared better on measures of limitation. Conclusions: When deciding which CSI to administer, measures of test limitation as well as measures of test discrimination should be considered. Identification of CSIs with high MR, low H/B, and low LDM, may have implications for their use in clinical practice.


2020 ◽  
Vol 17 (9) ◽  
pp. 851-857
Author(s):  
Seon Jin Yim ◽  
Dahyun Yi ◽  
Min Soo Byun ◽  
Kiyoung Sung ◽  
Dong Young Lee

Objective We investigated whether the addition of Alzheimer’s disease-signature region cortical thickness (AD-Ct) and hippocampal volume (Hv) obtained from brain MRI to subjective memory complaints and informant-reports of cognitive decline enhances the screening accuracy for cognitive disorders in a memory clinic setting.Methods 120 participants (40 cognitively normal, 40 MCI, 40 dementia) underwent clinical evaluation, neuropsychological assessment, and brain MRI. The Subjective Memory Complaints Questionnaire (SMCQ) and Seoul Informant-Report Questionnaire for Dementia (SIRQD) were applied to assess subjective memory complaints and informant-reports of cognitive decline respectively. Logistic regression and ROC curve analyses were conducted to compare the screening abilities of SMCQ+SIRQD, SMCQ+SIRQD+Hv, and SMCQ+SIRQD+AD-Ct models for cognitive disorders.Results SMCQ+SIRQD+Hv model indicated better screening accuracy for MCI and overall cognitive disorder (CDall) than SMCQ+ SIRQD model. SMCQ+SIRQD+AD-Ct model had superior screening accuracy for dementia in comparison to SMCQ+SIRQD model. ROC curve analyses revealed that SMCQ+SIRQD+Hv model had the greatest area under the curve (AUC) for screening MCI and CDall (AUC: 0.941 and 0.957), while SMCQ+SIRQD+AD-Ct model had the greatest AUC for screening dementia (AUC: 0.966).Conclusion Our results suggest that the addition of regional quantitative MRI data enhances the screening ability of subjective memory complaints and informant-reports of cognitive decline for MCI and dementia.


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