Free-Cog: Pragmatic Test Accuracy Study and Comparison with Mini-Addenbrooke’s Cognitive Examination

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.

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.


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.


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.


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.


BJGP Open ◽  
2021 ◽  
pp. BJGPO.2021.0058
Author(s):  
Samuel Thomas Creavin ◽  
Judy Haworth ◽  
Mark Fish ◽  
Sarah Cullum ◽  
Anthony Bayer ◽  
...  

BackgroundGPs often report using clinical judgement to diagnose dementia.AimInvestigate the accuracy of GPs’ clinical judgement for the diagnosis of dementia.Design & settingDiagnostic test accuracy study, recruiting from 21 practices around Bristol.MethodThe clinical judgement of the treating GP (index test) was based on the information immediately available at their initial consultation with a person aged over 70 years who had cognitive symptoms. The reference standard was an assessment by a specialist clinician, based on a standardised clinical examination and made according to ICD-10 criteria for dementia.Results240 people were recruited, with a median age of 80 years (IQR 75–84 years), of whom 126 (53%) were men and 132 (55%) had dementia. The median duration of symptoms was 24 months (IQR 12–36 months) and the median ACE-III score was 75 (IQR 65–87). GP clinical judgement had sensitivity 56% (95% CI 47% to 65%) and specificity 89% (95% CI 81% to 94%). Positive likelihood ratio was higher in people aged 70–79 years (6.5, 95% CI 2.9–15) compared to people aged ≥80 years (3.6, 95% CI 1.7–7.6), and in women (10.4, 95% CI 3.4–31.7) compared to men (3.2, 95% CI 1.7–6.2), whereas the negative likelihood ratio was similar in all groups.ConclusionA GP clinical judgement of dementia is specific, but confirmatory testing is needed to exclude dementia in symptomatic people who GPs judge as not having dementia.


2020 ◽  
Author(s):  
Andrew J Larner

AbstractCognitive screening instruments (CSIs) for dementia and mild cognitive impairment are usually characterised in terms of measures of discrimination such as sensitivity, specificity, and likelihood ratios. However, CSIs also have limitations. Several metrics exist which may be used to denote test limitations but they are seldom examined. Data from several pragmatic test accuracy studies of CSIs were interrogated to calculate various measures of limitation, namely: misclassification rate; net harm to net benefit ratio; and the likelihood to be diagnosed or misdiagnosed. Intra- and inter-test performance for measures of discrimination and limitation were compared. The study found that some tests with very high sensitivity but low specificity for dementia fared poorly on measures of limitation, with high misclassification rates, low net harm to net benefit ratios, and low likelihoods to be diagnosed or misdiagnosed; some had likelihoods favouring misdiagnosis over diagnosis. Tests with a better balance of sensitivity and specificity fared better on measures of limitation. When choosing which CSIs to administer, measures of test limitation should be considered as well as measures of test discrimination. Although high test sensitivity may be desirable to avoid false negatives, false positives also have a cost. Identification of tests having high misclassification rate, low net harm to net benefit ratio, and low likelihood to be diagnosed or misdiagnosed, may have implications for their use in clinical practice.


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.


2016 ◽  
Vol 1 (6) ◽  
pp. 47-54 ◽  
Author(s):  
Jeffrey J. DiGiovanni ◽  
Travis L. Riffle

The search for best practices in hearing aid fittings and aural rehabilitation has generally used the audiogram and function stemming from peripheral sensitivity. In recent years, however, we have learned that individuals respond differently to various hearing aid and aural rehabilitation techniques based on cognitive abilities. In this paper, we review basic concepts of working memory and the literature driving our knowledge in newer concepts of hearing aid fitting and aural rehabilitation.


Author(s):  
Janwillem W.H. Kocks ◽  
Heinze J.H. Andringa ◽  
Ellen van Heijst ◽  
Renaud Louis ◽  
Inigo Ojanguren Arranz ◽  
...  

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