scholarly journals Screening for dementia: Q* index as a global measure of test accuracy revisited

2020 ◽  
Author(s):  
Andrew J Larner
Keyword(s):  
Odds Ratio ◽  
Meta Analysis ◽  
Roc Curves ◽  
Diagnostic Odds Ratio ◽  
Test Accuracy ◽  
Cognitive Screening ◽  
Optimal Test ◽  
Global Parameter ◽  
Accuracy Study ◽  
Q Index

AbstractReceiver operating characteristic (ROC) curves intersect the downward diagonal through ROC space at a point, the Q* index, where by definition sensitivity and specificity are equal. Aside from its use in meta-analysis, Q* index has also been suggested as a possible global parameter summarising test accuracy of cognitive screening instruments and as a definition for optimal test cut-off. Area under the ROC curve (AUC ROC) is a recognised measure of test accuracy. This study compared different methods for determining Q* index (both graphical and calculation from diagnostic odds ratio) and AUC ROC (integration and calculation from diagnostic odds ratio) using the dataset of a prospective screening test accuracy study of the Mini-Addenbrooke’s Cognitive Examination. The different methods did not agree. DOR-based calculations gave a very sensitive cut-off but with poorer global metrics than the graphical method. DOR-based calculations are not recommended for defining optimal test cut-off or test accuracy.

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

2021 ◽  
Author(s):  
Gashirai K Mbizvo ◽  
Andrew J Larner
Keyword(s):  
Receiver Operating Characteristic ◽  
Screening Test ◽  
Odds Ratio ◽  
Operating Characteristic ◽  
Area Under The Curve ◽  
Diagnostic Odds Ratio ◽  
Test Accuracy ◽  
Cognitive Screening ◽  
Binary Classifiers ◽  
Addenbrooke’S Cognitive Examination

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.

scholarly journals The Q* Index: A Useful Global Measure of Dementia Screening Test Accuracy

2015 ◽  
Vol 5 (2) ◽  
pp. 265-270 ◽  
Author(s):  
A.J. Larner
Keyword(s):  
Sensitivity And Specificity ◽  
Roc Curve ◽  
Classification Accuracy ◽  
Youden Index ◽  
Test Accuracy ◽  
Correct Classification ◽  
Cognitive Screening ◽  
Global Parameter ◽  
Q Index ◽  
Addenbrooke’S Cognitive Examination

Background/Aims: Single, global or unitary, indicators of test diagnostic performance have intuitive appeal for clinicians. The Q* index, the point in receiver operating characteristic (ROC) curve space closest to the ideal top left-hand corner and where test sensitivity and specificity are equal, is one such measure. Methods: Datasets from four pragmatic accuracy studies which examined the Mini-Mental State Examination, Addenbrooke's Cognitive Examination-Revised, Montreal Cognitive Assessment, Test Your Memory test, and Mini-Addenbrooke's Cognitive Examination were examined to calculate and compare the Q* index, the maximal correct classification accuracy, and the maximal Youden index, as well as the sensitivity and specificity at these cutoffs. Results: Tests ranked similarly for the Q* index and the area under the ROC curve (AUC ROC). The Q* index cutoff was more sensitive (and less specific) than the maximal correct classification accuracy cutoff, and less sensitive (and more specific) than the maximal Youden index cutoff. Conclusion: The Q* index may be a useful global parameter summarising the test accuracy of cognitive screening instruments, facilitating comparison between tests, and defining a possible test cutoff value. As the point of equal sensitivity and specificity, its use may be more intuitive and appealing for clinicians than AUC ROC.

scholarly journals Prognostic Value of N-terminal Probrain Natriuretic Peptide for Patients with Acute Respiratory Distress Syndrome: A Systematic Review and Meta-Analysis

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Qi Ni ◽  
Chaoqian Li ◽  
Hua Lin
Keyword(s):  
Systematic Review ◽  
Acute Respiratory Distress Syndrome ◽  
Likelihood Ratio ◽  
Odds Ratio ◽  
Distress Syndrome ◽  
Meta Analysis ◽  
Positive Likelihood Ratio ◽  
Negative Likelihood Ratio ◽  
Diagnostic Odds Ratio ◽  
Sensitivity Specificity

Objectives. The mortality rate of patients with acute respiratory distress syndrome (ARDS) is high. Hence, it is crucial to identify a reliable biomarker with wide clinical applications for predicting the prognosis of patients with ARDS. This systematic review and meta-analysis was conducted to investigate the value of plasma N-terminal probrain natriuretic peptide (NT-proBNP) for predicting mortality in patients with ARDS. Methods. An electronic search of databases including PubMed, Web of Science, Cochrane Library, and Chinese National Knowledge Infrastructure was conducted up to May 31, 2019, without language restrictions. The quality of the included studies was evaluated using QUADAS-2. Data were extracted and analyzed to obtain pooled estimates of sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio. A forest graph was used to evaluate heterogeneity. Potential causes of heterogeneity were further explored by subgroup analysis based on the testing day, testing method, observation endpoint, or cut-off points. A summary receiver operating characteristic curve was drawn to obtain the pooled area under the curve. Results. A total of 7 studies involving 581 patients with ARDS were included. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were as follows: 0.79 (95% CI: 0.72–0.84), 0.79 (95% CI: 0.66–0.88), 3.68 (95% CI: 2.16–6.28), 0.27 (95% CI: 0.20–0.38), and 13.58 (95% CI: 6.17–29.90), respectively. The results of subgroup analysis showed that the testing day influenced the summary sensitivity and that the cut-off points influenced the summary sensitivity and specificity. Conclusion. Our results indicate that elevated plasma NT-proBNP levels have a moderate value for predicting the mortality of patients with ARDS.

Blood circulating miRNAs as biomarkers of Alzheimer’s disease: a systematic review and meta-analysis

2019 ◽  
Vol 13 (12) ◽  
pp. 1045-1054
Author(s):  
Ya-Heng Zhang ◽  
Shu-Feng Bai ◽  
Jun-Qiang Yan
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Odds Ratio ◽  
Diagnostic Performance ◽  
Meta Analysis ◽  
Diagnostic Odds Ratio ◽  
Circulating Mirnas ◽  
Cognitively Normal ◽  
Specificity And Sensitivity ◽  
Normal Controls

Aim: It is already known that miRNAs can be differentially expressed in Alzheimer’s disease (AD). We aimed to evaluate the performance of miRNAs from blood as potential biomarkers for AD. Materials & methods: MEDLINE, PubMed and Embase were searched for studies about peripheral blood miRNAs that could discriminate patients with AD from cognitively normal controls. The data regarding the specificity and sensitivity were extracted. STATA 14.0 was used to analyze the data. Results: Ten studies containing 770 AD and 664 normal controls. The analysis showed that miRNAs presented excellent diagnostic performance and the overall sensitivity was 0.80 (95% CI: 0.75–0.83), specificity was 0.83 (95% CI: 0.78–0.87) and diagnostic odds ratio was 14 (95% CI: 11–19). Subgroup analysis suggested that the Caucasian group and blood group showed a better performance in AD diagnosis and the diagnostic odds ratio was 42 and 34, respectively. Conclusion: This meta-analysis showed that miRNAs may be a promising biomarkers for AD.

scholarly journals Diagnostic Accuracy of Epithelial Membrane Antigen for Malignant Effusions: A Meta-Analysis

2016 ◽  
Vol 31 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Wentao Lin ◽  
Xiaoxue Liu ◽  
Ying Cen
Keyword(s):  
Likelihood Ratio ◽  
Sensitivity And Specificity ◽  
Odds Ratio ◽  
Epithelial Membrane Antigen ◽  
Meta Analysis ◽  
Positive Likelihood Ratio ◽  
Negative Likelihood Ratio ◽  
Diagnostic Odds Ratio ◽  
Diagnostic Potential ◽  
Malignant Effusions

Background and Objectives Body cavity fluid examination sometimes presents a diagnostic challenge in cytology practice. This meta-analysis was undertaken to comprehensively assess the diagnostic potential of epithelial membrane antigen (EMA) in malignant effusions. Materials and Methods All relevant original articles about EMA in the diagnosis of malignant effusions published up to July 1, 2014 were retrieved. The overall sensitivity, specificity, positive and negative likelihood ratio, diagnostic odds ratio, and summary receiver operating characteristic (SROC) curve were pooled to evaluate the diagnostic value of EMA for malignant effusions using the Meta-Disc 1.4 and STATA 12.0 statistical software. Results Eleven studies met the inclusion criteria for the meta-analysis and the summary estimates for EMA in the diagnosis of malignant effusions were as follows: sensitivity 0.9 (95% CI 0.83-0.87), specificity 0.87 (95% CI 0.96-0.99), positive likelihood ratio 5.8 (95% CI 15.59-36.37), negative likelihood ratio 0.15 (95% CI 0.07-0.20) and diagnostic odds ratio 52.63 (95% CI 20.91-132.49). The SROC curve indicated that the maximum joint sensitivity and specificity (Q-value) was 0.88; the area under the curve was 0.94. Conclusion The present meta-analysis indicated that EMA may be a useful diagnostic tool with good sensitivity and specificity for differentiating malignant effusions from benign effusions.

MACE versus MoCA: equivalence or superiority? Pragmatic diagnostic test accuracy study

2017 ◽  
Vol 29 (6) ◽  
pp. 931-937 ◽  
Author(s):  
A.J. Larner
Keyword(s):  
Secondary Care ◽  
Characteristic Curve ◽  
High Sensitivity ◽  
Screening Instrument ◽  
Test Accuracy ◽  
Cognitive Screening ◽  
Net Benefit ◽  
Dementia Diagnosis ◽  
Predictive Values ◽  
Accuracy Study

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.

MACE for the Diagnosis of Dementia and MCI: 3-Year Pragmatic Diagnostic Test Accuracy Study

2018 ◽  
Vol 45 (5-6) ◽  
pp. 300-307 ◽  
Author(s):  
John C. Williamson ◽  
Andrew J. Larner
Keyword(s):  
Diagnostic Test ◽  
Cognitive Disorders ◽  
High Sensitivity ◽  
Diagnostic Test Accuracy ◽  
Test Accuracy ◽  
Cognitive Screening ◽  
Predictive Values ◽  
Diagnosis Of Dementia ◽  
Accuracy Study ◽  
Secondary Care Setting

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.

scholarly journals Delta Neutrophil Index for the Prediction of Prognosis in Acute Gastrointestinal Diseases; Diagnostic Test Accuracy Meta-Analysis

2020 ◽  
Vol 9 (4) ◽  
pp. 1133
Author(s):  
Hae Min Jeong ◽  
Chang Seok Bang ◽  
Jae Jun Lee ◽  
Gwang Ho Baik
Keyword(s):  
Diagnostic Test ◽  
Poor Prognosis ◽  
Prognostic Biomarker ◽  
Meta Analysis ◽  
Area Under The Curve ◽  
Gastrointestinal Diseases ◽  
Diagnostic Odds Ratio ◽  
Diagnostic Test Accuracy ◽  
Test Accuracy ◽  
Delta Neutrophil Index

Delta neutrophil index (DNI) is a novel diagnostic and prognostic biomarker of various infectious or inflammatory conditions. However, data on optimal measurement time are scarce, and no studies have evaluated the potential role of the DNI as a prognostic biomarker of gastrointestinal diseases with diagnostic test accuracy meta-analysis. Core databases were searched. The inclusion criteria were as follows: patients who have gastrointestinal diseases and DNI measurements presenting diagnostic indices for predicting the prognosis, including severity, surgical outcomes, and mortality from gastrointestinal diseases. We identified twelve studies for the systematic review and ten studies for the quantitative analysis. Pooled area under the curve, sensitivity, specificity, and diagnostic odds ratio of DNI at the initial admission date were 0.82 (95% confidence interval: 0.78–0.85), 0.75 (0.52–0.89), 0.76 (0.63–0.86), and 10 (3–35), respectively. Meta-regression showed no reasons for heterogeneity and publication bias was not detected. Fagan’s nomogram indicated that the posterior probability of ‘poor prognosis’ was 76% if the test was positive, and ‘no poor prognosis’ was 25% if the test was negative. The DNI can be considered as a reliable initial measurement biomarker for predicting prognosis in patients with gastrointestinal diseases,

scholarly journals Contrast-enhanced endoscopic ultrasound for the differential diagnosis between benign and malignant lymph nodes: a meta-analysis

2019 ◽  
Vol 07 (04) ◽  
pp. E504-E513 ◽  
Author(s):  
Andrea Lisotti ◽  
Claudio Ricci ◽  
Marta Serrani ◽  
Claudio Calvanese ◽  
Sandro Sferrazza ◽  
...  
Keyword(s):  
Differential Diagnosis ◽  
Lymph Nodes ◽  
Likelihood Ratio ◽  
Endoscopic Ultrasound ◽  
Odds Ratio ◽  
Meta Analysis ◽  
Diagnostic Odds Ratio ◽  
Significant Heterogeneity ◽  
Contrast Enhanced ◽  
Malignant Lymph Nodes

Abstract Background The differential diagnosis between benign and malignant lymph nodes (LNs) is crucial for patient management and clinical outcome. The use of contrast-enhanced endoscopic ultrasound (EUS) has been evaluated in several studies with diverse results. The aim of this meta-analysis was to evaluate the pooled diagnostic accuracy of contrast-enhanced EUS (CE-EUS) and contrast-enhanced harmonic EUS (CH-EUS) in this setting. Methods A systematic electronic search was performed, including all original papers dealing with assessment of the nature of the LNs using CE-EUS or CH-EUS. A meta-analysis was performed to obtain pooled sensitivity, specificity, positive and negative likelihood ratio, and diagnostic odds ratio. The Summary Receiver Operating Characteristic (ROC) Curve method was used to calculate the area under the curve. Statistical analysis was carried out using Meta-Disc V.1.4, Stata V.12.0 and Review Manager V.5.2. Results Among 210 pertinent studies, four (336 patients) were included in the analysis. The pooled sensitivity was 82.1 % (75.1 – 87.7 %) and pooled specificity was 90.7 % (85.9 – 94.3 %) with significant heterogeneity found in sensitivity; the positive-likelihood ratio (LR) was 7.77 (5.09 – 11.85) and the negative-LR was 0.15 (0.05 – 0.46); the pooled diagnostic odds ratio (DOR) was 54 (15 – 190). Subgroup analysis including studies performed using CH-EUS (two studies, 177 LNs) showed a pooled sensitivity of 87.7 % (77.0 – 93.9 %) and a pooled specificity of 91.8 % (84.5 % – 96.4 %) with no significant heterogeneity; the pooled positive-LR was 9.51 (4.95 – 18.28) and the pooled negative-LR was 0.14 (0.06 – 0.35); pooled DOR was 68.42 (15.5 – 301.4). Conclusions From these data, CE-EUS is not recommended due to inadequate sensitivity. On the other hand, CH-EUS studies showed optimal accuracy (pooled sensitivity 87.7 % and specificity 91.8 %), comparable to elastography and even EUS-guided fine needle aspiration (EUS-FNA), suggesting a role in the diagnostic algorithm.

Accuracy of Telephone-Based Cognitive Screening Tests: Systematic Review and Meta-Analysis

2020 ◽  
Vol 17 (5) ◽  
pp. 460-471
Author(s):  
Emma Elliott ◽  
Claire Green ◽  
David J. Llewellyn ◽  
Terence J. Quinn
Keyword(s):  
Meta Analysis ◽  
Cognitive Status ◽  
Screening Tests ◽  
Test Accuracy ◽  
Supporting Evidence ◽  
Cognitive Screening ◽  
Cognitive Assessments ◽  
Face To Face ◽  
The Face ◽  
The Many

Background: Telephone-based cognitive assessments may be preferable to in-person testing in terms of test burden, economic and opportunity cost. Objective: We sought to determine the accuracy of telephone-based screening for the identification of dementia or Mild Cognitive Impairment (MCI). Methods: Five multidisciplinary databases were searched. Two researchers independently screened articles and extracted data. Eligible studies compared any multi-domain telephone-based assessment of cognition to the face-to-face diagnostic evaluation. Where data allowed, we pooled test accuracy metrics using the bivariate approach. Results: From 11,732 titles, 34 papers were included, describing 15 different tests. There was variation in test scoring and quality of included studies. Pooled analyses of accuracy for dementia: Telephone Interview for Cognitive Status (TICS) (<31/41) sensitivity: 0.92, specificity: 0.66 (6 studies); TICSmodified (<28/50) sensitivity: 0.91, specificity: 0.91 (3 studies). For MCI: TICS-modified (<33/50) sensitivity: 0.82, specificity: 0.87 (3 studies); Telephone-Montreal Cognitive Assessment (<18/22) sensitivity: 0.98, specificity: 0.69 (2 studies). Conclusion: There is limited diagnostic accuracy evidence for the many telephonic cognitive screens that exist. The TICS and TICS-m have the greatest supporting evidence; their test accuracy profiles make them suitable as initial cognitive screens where face to face assessment is not possible.

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