scholarly journals Efficiency of Predicting Risk in Word Reading Using Fewer, Easier Letters

2011 ◽  
Vol 37 (1) ◽  
pp. 17-25 ◽  
Author(s):  
Yaacov Petscher ◽  
Young-Suk Kim
Keyword(s):  
Diagnostic Accuracy ◽  
Predictive Power ◽  
Operating Characteristic ◽  
Word Reading ◽  
Roc Curves ◽  
Scale Analysis ◽  
Early Screening ◽  
Mokken Scale Analysis ◽  
Sensitivity Specificity ◽  
Hierarchical Scale

Letter-name identification has been widely used as part of early screening to identify children who might be at risk for future word reading difficulty. The goal of the present study was to examine whether a reduced set of letters could have similar diagnostic accuracy rather than a full set (i.e., 26 letters) when used as a screen. First, we examined whether a hierarchical scale existed among letters by using a Mokken scale analysis. Then, we contrasted diagnostic accuracy among the 5, 10, 15, and 20 easiest letters, with all 26 letters by using receiver operating characteristic (ROC) curves and indices of sensitivity, specificity, positive predictive power, and negative predictive power. Results demonstrated that a hierarchical scale existed among items in the letter-name knowledge test. In addition, assessing students on the easiest 15 letters was not statistically distinguished from all 26 letters in diagnostic accuracy. The implications of the results for the use of a Mokken scale analysis in educational research are discussed.

scholarly journals Diagnostic performances of manual and automated reticulocyte parameters in anaemic cats

2017 ◽  
Vol 20 (2) ◽  
pp. 122-127 ◽  
Author(s):  
Saverio Paltrinieri ◽  
Marco Fossati ◽  
Valentina Menaballi
Keyword(s):  
Receiver Operating Characteristic ◽  
Sensitivity And Specificity ◽  
Operating Characteristic ◽  
Positive Likelihood Ratio ◽  
Roc Curves ◽  
Blood Samples ◽  
Production Index ◽  
Instrumental Measurement ◽  
Sensitivity Specificity ◽  
Reticulocyte Production

Objectives The objective of this study was to evaluate the diagnostic performances of manual and instrumental measurement of reticulocyte percentage (Ret%), reticulocyte number (Ret#) and reticulocyte production index (RPI) to differentiate regenerative anaemia (RA) from non-regenerative anaemia (NRA) in cats. Methods Data from 106 blood samples from anaemic cats with manual counts (n = 74; 68 NRA, six RA) or instrumental counts of reticulocytes (n = 32; 25 NRA, seven RA) collected between 1995 and 2013 were retrospectively analysed. Sensitivity, specificity and positive likelihood ratio (LR+) were calculated using either cut-offs reported in the literature or cut-offs determined from receiver operating characteristic (ROC) curves. Results All the reticulocyte parameters were significantly higher in cats with RA than in cats with NRA. All the ROC curves were significantly different ( P <0.001) from the line of no discrimination, without significant differences between the three parameters. Using the cut-offs published in literature, the Ret% (cut-off: 0.5%) was sensitive (100%) but not specific (<75%), the RPI (cut-off: 1.0) was specific (>92%) but not sensitive (<15%), and the Ret# (cut-off: 50 × 10³/µl) had a sensitivity and specificity >80% and the highest LR+ (manual count: 14; instrumental count: 6). For all the parameters, sensitivity and specificity approached 100% using the cut-offs determined by the ROC curves. These cut-offs were higher than those reported in the literature for Ret% (manual: 1.70%; instrumental: 3.06%), lower for RPI (manual: 0.39; instrumental: 0.59) and variably different, depending on the method (manual: 41 × 10³/µl; instrumental: 57 × 10³/µl), for Ret#. Using these cut-offs, the RPI had the highest LR+ (manual: 22.7; instrumental: 12.5). Conclusions and relevance This study indicated that all the reticulocyte parameters may confirm regeneration when the pretest probability is high, while when this probability is moderate, RA should be identified using the RPI providing that cut-offs <1.0 are used.

scholarly journals Feasibility and Validity of Computed Tomography-Derived Fractional Flow Reserve in Patients With Severe Aortic Stenosis

2020 ◽  
Author(s):  
Michael Michail ◽  
Abdul-Rahman Ihdayhid ◽  
Andrea Comella ◽  
Udit Thakur ◽  
James D. Cameron ◽  
...  
Keyword(s):  
Aortic Stenosis ◽  
Diagnostic Accuracy ◽  
Operating Characteristic ◽  
Severe Aortic Stenosis ◽  
Characteristic Curve ◽  
Fractional Flow ◽  
Predictive Values ◽  
Flow Reserve ◽  
Artery Disease ◽  
Sensitivity Specificity

Background: Coronary artery disease is common in patients with severe aortic stenosis. Computed tomography-derived fractional flow reserve (CT-FFR) is a clinically used modality for assessing coronary artery disease, however, its use has not been validated in patients with severe aortic stenosis. This study assesses the safety, feasibility, and validity of CT-FFR in patients with severe aortic stenosis. Methods: Prospectively recruited patients underwent standard-protocol invasive FFR and coronary CT angiography (CTA). CTA images were analyzed by central core laboratory (HeartFlow, Inc) for independent evaluation of CT-FFR. CT-FFR data were compared with FFR (ischemia defined as FFR ≤0.80). Results: Forty-two patients (68 vessels) underwent FFR and CTA; 39 patients (92.3%) and 60 vessels (88.2%) had interpretable CTA enabling CT-FFR computation. Mean age was 76.2±6.7 years (71.8% male). No patients incurred complications relating to premedication, CTA, or FFR protocol. Mean FFR and CT-FFR were 0.83±0.10 and 0.77±0.14, respectively. CT calcium score was 1373.3±1392.9 Agatston units. On per vessel analysis, there was positive correlation between FFR and CT-FFR (Pearson correlation coefficient, R =0.64, P <0.0001). Sensitivity, specificity, positive predictive value, and negative predictive values were 73.9%, 78.4%, 68.0%, and 82.9%, respectively, with 76.7% diagnostic accuracy. The area under the receiver-operating characteristic curve for CT-FFR was 0.83 (0.72–0.93, P <0.0001), which was higher than that of CTA and quantitative coronary angiography ( P =0.01 and P <0.001, respectively). Bland-Altman plot showed mean bias between FFR and CT-FFR as 0.059±0.110. On per patient analysis, the sensitivity, specificity, positive predictive, and negative predictive values were 76.5%, 77.3%, 72.2%, and 81.0% with 76.9% diagnostic accuracy. The per patient area under the receiver-operating characteristic curve analysis was 0.81 (0.67–0.95, P <0.0001). Conclusions: CT-FFR is safe and feasible in patients with severe aortic stenosis. Our data suggests that the diagnostic accuracy of CT-FFR in this cohort potentially enables its use in clinical practice and provides the foundation for future research into the use of CT-FFR for coronary evaluation pre-aortic valve replacement.

scholarly journals Association between Levels of IgA Antibodies to Tissue Transglutaminase and Gliadin-Related Nonapeptides in Dermatitis Herpetiformis

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Justyna Gornowicz-Porowska ◽  
Monika Bowszyc-Dmochowska ◽  
Agnieszka Seraszek-Jaros ◽  
Elżbieta Kaczmarek ◽  
Marian Dmochowski
Keyword(s):  
Diagnostic Accuracy ◽  
Receiver Operating Characteristic ◽  
Causal Relationship ◽  
Operating Characteristic ◽  
Dermatitis Herpetiformis ◽  
Tissue Transglutaminase ◽  
Roc Curves ◽  
Healthy Controls ◽  
Iga Antibodies ◽  
Healthy Persons

Dermatitis herpetiformis (DH) is an autoimmunity-driven inflammatory blistering dermatosis associated with a gluten-dependent enteropathy. Tissue transglutaminase (tTG) and nonapeptides of gliadin (npG) are considered in its pathomechanism/diagnostics. Here, the diagnostic accuracy of anti-tTG/anti-npG IgA ELISAs in Slavic DH patients with active skin rash was assessed through creating receiver operating characteristic (ROC) curves, determining cutoff values, and calculating correlations between levels of anti-tTG/anti-npG IgA in DH, IgA/neutrophil-mediated non-DH patients and healthy persons. Altogether, sera from 80 Slavic individuals were examined. There were negligible differences between cutoff points obtained by the ELISAs manufacturer and those in this study. There were statistically significant correlations between levels of anti-tTG/anti-npG IgA in both DH group and the group of IgA/neutrophil-mediated non-DH dermatoses. There was no such correlation in healthy controls. It seems that IgA autoantibodies to tTG and npG in the IgA/neutrophil-mediated DH are produced in the coordinated way implying their causal relationship.

scholarly journals Diagnostic accuracy of a urine dipstick for detecting albuminuria in hypertensive patients

F1000Research ◽  
2021 ◽  
Vol 9 ◽  
pp. 1244
Author(s):  
Phornwipa Panta ◽  
Win Techakehakij
Keyword(s):  
Diagnostic Accuracy ◽  
Predictive Value ◽  
Operating Characteristic ◽  
Characteristic Curve ◽  
Hypertensive Patients ◽  
Spot Urine ◽  
Urine Dipstick ◽  
Urine Albumin ◽  
Low Sensitivity ◽  
Sensitivity Specificity

Background: Screening for albuminuria is generally recommended among patients with hypertension. While the urine dipstick is commonly used for screening urine albumin, there is little evidence about its diagnostic accuracy among these patients in Thailand. This study aimed to assess the diagnostic accuracy of a dipstick in Thai hypertensive patients for detecting albuminuria. Methods: This study collected the data of 3,067 hypertensive patients, with the results of urine dipstick and urine albumin-to-creatinine ratio (ACR) from random single spot urine being examined in the same day at least once, at Lampang Hospital, Thailand, during 2018. For ACR, a reference standard of ≥ 30 mg/g was applied to indicate the presence of albuminuria. Results: The sensitivity, specificity, positive predictive value (PPV), and negative predictive value of the trace result from dipsticks were 53.6%, 94.5%, 86.5%, and 75.5%, respectively. The area under the receiver operating characteristic curve of the dipstick was 0.748. Conclusion: Using the dipstick for screening albuminuria among hypertensive patients should not be recommended for mass screening due to its low sensitivity. In response to high PPV, a trace threshold of the dipstick may be used to indicate presence of albuminuria.

scholarly journals Diagnostic accuracy of a urine dipstick for detecting albuminuria in hypertensive patients

F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 1244
Author(s):  
Phornwipa Panta ◽  
Win Techakehakij
Keyword(s):  
Diagnostic Accuracy ◽  
Predictive Value ◽  
Operating Characteristic ◽  
Characteristic Curve ◽  
Hypertensive Patients ◽  
Spot Urine ◽  
Urine Dipstick ◽  
Urine Albumin ◽  
Low Sensitivity ◽  
Sensitivity Specificity

Background: Screening for albuminuria is generally recommended among patients with hypertension. While the urine dipstick is commonly used for screening urine albumin, there is little evidence about its diagnostic accuracy among these patients. This study aimed to assess the diagnostic accuracy of a dipstick in Thai hypertensive patients for detecting albuminuria. Methods: This study collected the data of 3,067 hypertensive patients, with the results of urine dipstick and urine albumin-to-creatinine ratio (ACR) from random single spot urine being examined in the same day at least once, at Lampang Hospital, Thailand, during 2018. For ACR, a reference standard of ≥ 30 mg/g was applied to indicate the presence of albuminuria. Results: The sensitivity, specificity, positive predictive value (PPV), and negative predictive value of the trace result from dipsticks were 53.6%, 94.5%, 86.5%, and 75.5%, respectively. The area under the receiver operating characteristic curve of the dipstick was 0.748. Conclusion: Using the dipstick for screening albuminuria among hypertensive patients should not be recommended due to its low sensitivity. In response to high PPV, a trace threshold of the dipstick may be used to indicate presence of albuminuria.

scholarly journals Seeking a Valid Gold Standard for an Innovative, Dialect-Neutral Language Test

2014 ◽  
Vol 57 (2) ◽  
pp. 495-508 ◽  
Author(s):  
Barbara Zurer Pearson ◽  
Janice E. Jackson ◽  
Haotian Wu
Keyword(s):  
Diagnostic Accuracy ◽  
Language Impairment ◽  
Gold Standard ◽  
Predictive Power ◽  
Clinical Status ◽  
Variation Norm ◽  
American Children ◽  
Sensitivity Specificity ◽  
Neutral Language ◽  
Gold Standards

PurposeIn this study, the authors explored alternative gold standards to validate an innovative, dialect-neutral language assessment.MethodParticipants were 78 African American children, ages 5;0 (years;months) to 6;11. Twenty participants had previously been identified as having language impairment. The Diagnostic Evaluation of Language Variation—Norm Referenced (DELV–NR; Seymour, Roeper, & J. de Villiers, 2005) was administered, and concurrent language samples (LSs) were collected. Using LS profiles as the gold standard, sensitivity, specificity, and other measures of diagnostic accuracy were compared for diagnoses made from the DELV–NR and participants' clinical status prior to recruitment. In a second analysis, the authors used results from the first analysis to make evidence-based adjustments in the estimates of DELV–NR diagnostic accuracy.ResultsAccuracy of the DELV–NR relative to LS profiles was greater than that of prior diagnoses, indicating that the DELV–NR was an improvement over preexisting diagnoses for this group. Specificity met conventional standards, but sensitivity was somewhat low. Reanalysis using the positive and negative predictive power of the preexisting diagnosis in a discrepant-resolution procedure revealed that estimates for sensitivity and specificity for the DELV–NR were .85 and .93, respectively.ConclusionThe authors found that, even after making allowances for the imperfection of available gold standards, clinical decisions made with the DELV–NR achieved high values on conventional measures of diagnostic accuracy.

Diagnostic Tests Distinguishing Good Tests From Bad and Even Ugly Ones

2000 ◽  
Vol 21 (4) ◽  
pp. 278-284 ◽  
Author(s):  
David Birnbaum ◽  
Barry M. Farr ◽  
David E. Shapiro
Keyword(s):  
Positive Result ◽  
Diagnostic Tests ◽  
Roc Analysis ◽  
Operating Characteristic ◽  
Bloodstream Infections ◽  
Roc Curves ◽  
Optimal Cutoff ◽  
Overall Performance ◽  
Sensitivity Specificity ◽  
Catheter Related Bloodstream Infection

This article focuses on the selection and interpretation of diagnostic tests, emphasizing the importance of understanding how their mathematical parameters affect the information they provide in various settings. The utility and limitations of sensitivity, specificity, predictive value, and receiver operating characteristic (ROC) curves are discussed using catheter-related bloodstream infections as an example. ROC curves have been used for selecting optimal cutoff values for a positive result and for selecting among several alternative diagnostic tests. For example, 16 different tests have been proposed for diagnosis of catheter-related bloodstream infection; ROC analysis provides an effective way to determine which test offers the best overall performance.

scholarly journals Inflammatory Breast Carcinoma: Elevated microRNA miR-181b-5p and Reduced miR-200b-3p, miR-200c-3p, and miR-203a-3p Expression as Potential Biomarkers with Diagnostic Value

Biomolecules ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1059
Author(s):  
Sarah Atef Fahim ◽  
Mahmoud Salah Abdullah ◽  
Nancy A. Espinoza-Sánchez ◽  
Hebatallah Hassan ◽  
Ayman M. Ibrahim ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Diagnostic Accuracy ◽  
Operating Characteristic ◽  
Area Under The Curve ◽  
Roc Curves ◽  
Diagnostic Value ◽  
Differentially Expressed Mirnas ◽  
E Box ◽  
Aggressive Breast Cancer ◽  
Potential Biomarkers

Inflammatory breast cancer (IBC) is a rare yet aggressive breast cancer variant, associated with a poor prognosis. The major challenge for IBC is misdiagnosis due to the lack of molecular biomarkers. We profiled dysregulated expression of microRNAs (miRNAs) in primary samples of IBC and non-IBC tumors using human breast cancer miRNA PCR array. We discovered that 28 miRNAs were dysregulated (10 were upregulated, while 18 were underexpressed) in IBC vs. non-IBC tumors. We identified 128 hub genes, which are putative targets of the differentially expressed miRNAs and modulate important cancer biological processes. Furthermore, our qPCR analysis independently verified a significantly upregulated expression of miR-181b-5p, whereas a significant downregulation of miR-200b-3p, miR-200c-3p, and miR-203a-3p was detected in IBC tumors. Receiver operating characteristic (ROC) curves implied that the four miRNAs individually had a diagnostic accuracy in discriminating patients with IBC from non-IBC and that miR-203a-3p had the highest diagnostic value with an AUC of 0.821. Interestingly, a combination of miR-181b-5p, miR-200b-3p, and miR-200c-3p robustly improved the diagnostic accuracy, with an area under the curve (AUC) of 0.897. Intriguingly, qPCR revealed that the expression of zinc finger E box-binding homeobox 2 (ZEB2) mRNA, the putative target of miR-200b-3p, miR-200c-3p, and miR-203a-3p, was upregulated in IBC tumors. Overall, this study identified a set of miRNAs serving as potential biomarkers with diagnostic relevance for IBC.

Dynamics of soluble syndecan-1 in maternal serum during and after pregnancies complicated by preeclampsia: a nested case control study

2019 ◽  
Vol 58 (1) ◽  
pp. 50-58 ◽  
Author(s):  
Lorenz Kuessel ◽  
Heinrich Husslein ◽  
Eliana Montanari ◽  
Michael Kundi ◽  
Gottfried Himmler ◽  
...  
Keyword(s):  
Endothelial Dysfunction ◽  
Predictive Power ◽  
Operating Characteristic ◽  
Area Under The Curve ◽  
Roc Curves ◽  
Serum Levels ◽  
Maternal Serum ◽  
Nested Case Control ◽  
Single Time Point ◽  
Control Study

Abstract Background We investigated the dynamics and the predictive value of soluble syndecan-1 (Sdc-1), a biomarker of endothelial dysfunction, in uneventful pregnancies and pregnancies complicated by preeclampsia (PE). Methods Serum levels of Sdc-1 were measured at sequential time points during and after uneventful pregnancies (control, n = 95) and pregnancies developing PE (PE_long, n = 12). Levels were further measured in women with symptomatic PE (PE_state, n = 46) at a single time point. Results Sdc-1 levels increased consistently throughout pregnancy. In the PE_long group Sdc-1 levels were lower at all visits throughout pregnancy, and reached significance in weeks 18–22 (p = 0.019), 23–27 (p = 0.009), 28–32 (p = 0.006) and 33–36 (p = 0.008). After delivery, Sdc-1 levels dropped sharply in all pregnancies but were significantly elevated in the PE_long group. The predictive power of Sdc-1 was evaluated analyzing receiver operating characteristic (ROC) curves. A significant power was reached at weeks 14–17 (area under the curve [AUC] 0.65, p = 0.025), 23–27 (AUC 0.73, p = 0.004) and 33–36 (AUC 0.75, p = 0.013). Conclusions In summary, Sdc-1 levels were lower in women developing PE compared to uneventful pregnancies and Sdc-1 might be useful to predict PE. After delivery, Sdc-1 levels remained higher in women with PE. Additional studies investigating the link between glycocalyx degradation, Sdc-1 levels and placental and endothelial dysfunction in pregnancies affected by PE are warranted.

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