Comparison of loop-mediated isothermal amplification assay and smear microscopy with culture for the diagnostic accuracy of tuberculosis.

PubMed

Gelaw, Baye; Shiferaw, Yitayal; Alemayehu, Marta; Bashaw, Abate Assefa

2017-01-17

Tuberculosis (TB) caused by Mycobacterium tuberculosis is one of the leading causes of death from infectious diseases worldwide. Sputum smear microscopy remains the most widely available pulmonary TB diagnostic tool particularly in resource limited settings. A highly sensitive diagnostic with minimal infrastructure, cost and training is required. Hence, we assessed the diagnostic performance of Loop-mediated isothermal amplification (LAMP) assay in detecting M.tuberculosis infection in sputum sample compared to LED fluorescent smear microscopy and culture. A cross-sectional study was conducted at the University of Gondar Hospital from June 01, 2015 to August 30, 2015. Pulmonary TB diagnosis using sputum LED fluorescence smear microscopy, TB-LAMP assay and culture were done. A descriptive analysis was used to determine demographic characteristics of the study participants. Analysis of sensitivity and specificity for smear microscopy and TB-LAMP compared with culture as a reference test was performed. Cohen's kappa was calculated as a measure of agreement between the tests. A total of 78 pulmonary presumptive TB patients sputum sample were analyzed. The overall sensitivity and specificity of LAMP were 75 and 98%, respectively. Among smear negative sputum samples, 33.3% sensitivity and 100% specificity of LAMP were observed. Smear microscopy showed 78.6% sensitivity and 98% specificity. LAMP and smear in series had sensitivity of 67.8% and specificity of 100%. LAMP and smear in parallel had sensitivity of 85.7% and specificity of 96%. The agreement between LAMP and fluorescent smear microscopy tests was very good (κ = 0.83, P-value ≤0.0001). TB-LAMP showed similar specificity but a slightly lower sensitivity with LED fluorescence microscopy. The specificity of LAMP and smear microscopy in series was high. The sensitivity of LAMP was insufficient for smear negative sputum samples.

Robust Sensitivity Analysis of Courses of Action Using an Additive Value Model

DTIC Science & Technology

2008-03-01

According to Clemen , sensitivity analysis answers, “What makes a difference in this decision?” (2001:175). Sensitivity analysis can also indicate...alternative to change. These models look for the new weighting that causes a specific alternative to rank above all others. 19 Barron and Schmidt first... Schmidt , 1988:123). A smaller objective function value indicates greater sensitivity. Wolters and Mareschal propose a similar approach using goal

Sensitivity and specificity of indocyanine green near-infrared fluorescence imaging in detection of metastatic lymph nodes in colorectal cancer: Systematic review and meta-analysis.

PubMed

Emile, Sameh H; Elfeki, Hossam; Shalaby, Mostafa; Sakr, Ahmad; Sileri, Pierpaolo; Laurberg, Søren; Wexner, Steven D

2017-11-01

This review aimed to determine the overall sensitivity and specificity of indocyanine green (ICG) near-infrared (NIR) fluorescence in sentinel lymph node (SLN) detection in Colorectal cancer (CRC). A systematic search in electronic databases was conducted. Twelve studies including 248 patients were reviewed. The median sensitivity, specificity, and accuracy rates were 73.7, 100, and 75.7. The pooled sensitivity and specificity rates were 71% and 84.6%. In conclusion, ICG-NIR fluorescence is a promising technique for detecting SLNs in CRC. © 2017 Wiley Periodicals, Inc.

The Sensitivity and Specificity of Potassium Hydroxide Smear and Fungal Culture Relative to Clinical Assessment in the Evaluation of Tinea Pedis: A Pooled Analysis

PubMed Central

Levitt, Jacob Oren; Levitt, Barrie H.; Akhavan, Arash; Yanofsky, Howard

2010-01-01

Background. There are relatively few studies published examining the sensitivity and specificity of potassium hydroxide (KOH) smear and fungal culture examination of tinea pedis. Objective. To evaluate the sensitivity and specificity of KOH smear and fungal culture for diagnosing tinea pedis. Methods. A pooled analysis of data from five similarly conducted bioequivalence trials for antifungal drugs was performed. Data from 460 patients enrolled in the vehicle arms of these studies with clinical diagnosis of tinea pedis supported by positive fungal culture were analyzed 6 weeks after initiation of the study to determine the sensitivity and specificity of KOH smear and fungal culture. Results. Using clinical assessment as the gold standard, the sensitivities for KOH smear and culture were 73.3% (95% CI: 66.3 to 79.5%) and 41.7% (34.6 to 49.1%), respectively. The respective specificities for culture and KOH smear were 77.7% (72.2 to 82.5%) and 42.5% (36.6 to 48.6%). Conclusion. KOH smear and fungal culture are complementary diagnostic tests for tinea pedis, with the former being the more sensitive test of the two, and the latter being more specific. PMID:20672004

Modeling Canadian Quality Control Test Program for Steroid Hormone Receptors in Breast Cancer: Diagnostic Accuracy Study.

PubMed

Pérez, Teresa; Makrestsov, Nikita; Garatt, John; Torlakovic, Emina; Gilks, C Blake; Mallett, Susan

The Canadian Immunohistochemistry Quality Control program monitors clinical laboratory performance for estrogen receptor and progesterone receptor tests used in breast cancer treatment management in Canada. Current methods assess sensitivity and specificity at each time point, compared with a reference standard. We investigate alternative performance analysis methods to enhance the quality assessment. We used 3 methods of analysis: meta-analysis of sensitivity and specificity of each laboratory across all time points; sensitivity and specificity at each time point for each laboratory; and fitting models for repeated measurements to examine differences between laboratories adjusted by test and time point. Results show 88 laboratories participated in quality control at up to 13 time points using typically 37 to 54 histology samples. In meta-analysis across all time points no laboratories have sensitivity or specificity below 80%. Current methods, presenting sensitivity and specificity separately for each run, result in wide 95% confidence intervals, typically spanning 15% to 30%. Models of a single diagnostic outcome demonstrated that 82% to 100% of laboratories had no difference to reference standard for estrogen receptor and 75% to 100% for progesterone receptor, with the exception of 1 progesterone receptor run. Laboratories with significant differences to reference standard identified with Generalized Estimating Equation modeling also have reduced performance by meta-analysis across all time points. The Canadian Immunohistochemistry Quality Control program has a good design, and with this modeling approach has sufficient precision to measure performance at each time point and allow laboratories with a significantly lower performance to be targeted for advice.

Diagnostic Accuracy of Memory Measures in Alzheimer’s Dementia and Mild Cognitive Impairment: a Systematic Review and Meta-Analysis

PubMed Central

Weissberger, Gali H.; Strong, Jessica V.; Stefanidis, Kayla B.; Summers, Mathew J.; Bondi, Mark W.; Stricker, Nikki H.

2018-01-01

With an increasing focus on biomarkers in dementia research, illustrating the role of neuropsychological assessment in detecting mild cognitive impairment (MCI) and Alzheimer’s dementia (AD) is important. This systematic review and meta-analysis, conducted in accordance with PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) standards, summarizes the sensitivity and specificity of memory measures in individuals with MCI and AD. Both meta-analytic and qualitative examination of AD versus healthy control (HC) studies (n = 47) revealed generally high sensitivity and specificity (≥ 80% for AD comparisons) for measures of immediate (sensitivity = 87%, specificity = 88%) and delayed memory (sensitivity = 89%, specificity = 89%), especially those involving word-list recall. Examination of MCI versus HC studies (n = 38) revealed generally lower diagnostic accuracy for both immediate (sensitivity = 72%, specificity = 81%) and delayed memory (sensitivity = 75%, specificity = 81%). Measures that differentiated AD from other conditions (n = 10 studies) yielded mixed results, with generally high sensitivity in the context of low or variable specificity. Results confirm that memory measures have high diagnostic accuracy for identification of AD, are promising but require further refinement for identification of MCI, and provide support for ongoing investigation of neuropsychological assessment as a cognitive biomarker of preclinical AD. Emphasizing diagnostic test accuracy statistics over null hypothesis testing in future studies will promote the ongoing use of neuropsychological tests as Alzheimer’s disease research and clinical criteria increasingly rely upon cerebrospinal fluid (CSF) and neuroimaging biomarkers. PMID:28940127

Comparison of the diagnostic ability of Moorfield’s regression analysis and glaucoma probability score using Heidelberg retinal tomograph III in eyes with primary open angle glaucoma

PubMed Central

Jindal, Shveta; Dada, Tanuj; Sreenivas, V; Gupta, Viney; Sihota, Ramanjit; Panda, Anita

2010-01-01

Purpose: To compare the diagnostic performance of the Heidelberg retinal tomograph (HRT) glaucoma probability score (GPS) with that of Moorfield’s regression analysis (MRA). Materials and Methods: The study included 50 eyes of normal subjects and 50 eyes of subjects with early-to-moderate primary open angle glaucoma. Images were obtained by using HRT version 3.0. Results: The agreement coefficient (weighted k) for the overall MRA and GPS classification was 0.216 (95% CI: 0.119 – 0.315). The sensitivity and specificity were evaluated using the most specific (borderline results included as test negatives) and least specific criteria (borderline results included as test positives). The MRA sensitivity and specificity were 30.61 and 98% (most specific) and 57.14 and 98% (least specific). The GPS sensitivity and specificity were 81.63 and 73.47% (most specific) and 95.92 and 34.69% (least specific). The MRA gave a higher positive likelihood ratio (28.57 vs. 3.08) and the GPS gave a higher negative likelihood ratio (0.25 vs. 0.44).The sensitivity increased with increasing disc size for both MRA and GPS. Conclusions: There was a poor agreement between the overall MRA and GPS classifications. GPS tended to have higher sensitivities, lower specificities, and lower likelihood ratios than the MRA. The disc size should be taken into consideration when interpreting the results of HRT, as both the GPS and MRA showed decreased sensitivity for smaller discs and the GPS showed decreased specificity for larger discs. PMID:20952832

Meta-analysis of diagnostic accuracy studies accounting for disease prevalence: alternative parameterizations and model selection.

PubMed

Chu, Haitao; Nie, Lei; Cole, Stephen R; Poole, Charles

2009-08-15

In a meta-analysis of diagnostic accuracy studies, the sensitivities and specificities of a diagnostic test may depend on the disease prevalence since the severity and definition of disease may differ from study to study due to the design and the population considered. In this paper, we extend the bivariate nonlinear random effects model on sensitivities and specificities to jointly model the disease prevalence, sensitivities and specificities using trivariate nonlinear random-effects models. Furthermore, as an alternative parameterization, we also propose jointly modeling the test prevalence and the predictive values, which reflect the clinical utility of a diagnostic test. These models allow investigators to study the complex relationship among the disease prevalence, sensitivities and specificities; or among test prevalence and the predictive values, which can reveal hidden information about test performance. We illustrate the proposed two approaches by reanalyzing the data from a meta-analysis of radiological evaluation of lymph node metastases in patients with cervical cancer and a simulation study. The latter illustrates the importance of carefully choosing an appropriate normality assumption for the disease prevalence, sensitivities and specificities, or the test prevalence and the predictive values. In practice, it is recommended to use model selection techniques to identify a best-fitting model for making statistical inference. In summary, the proposed trivariate random effects models are novel and can be very useful in practice for meta-analysis of diagnostic accuracy studies. Copyright 2009 John Wiley & Sons, Ltd.

Bacteriophage-based assays for the rapid detection of rifampicin resistance in Mycobacterium tuberculosis: a meta-analysis.

PubMed

Pai, Madhukar; Kalantri, Shriprakash; Pascopella, Lisa; Riley, Lee W; Reingold, Arthur L

2005-10-01

To summarize, using meta-analysis, the accuracy of bacteriophage-based assays for the detection of rifampicin resistance in Mycobacterium tuberculosis. By searching multiple databases and sources we identified a total of 21 studies eligible for meta-analysis. Of these, 14 studies used phage amplification assays (including eight studies on the commercial FASTPlaque-TB kits), and seven used luciferase reporter phage (LRP) assays. Sensitivity, specificity, and agreement between phage assay and reference standard (e.g. agar proportion method or BACTEC 460) results were the main outcomes of interest. When performed on culture isolates (N=19 studies), phage assays appear to have relatively high sensitivity and specificity. Eleven of 19 (58%) studies reported sensitivity and specificity estimates > or =95%, and 13 of 19 (68%) studies reported > or =95% agreement with reference standard results. Specificity estimates were slightly lower and more variable than sensitivity; 5 of 19 (26%) studies reported specificity <90%. Only two studies performed phage assays directly on sputum specimens; although one study reported sensitivity and specificity of 100 and 99%, respectively, another reported sensitivity of 86% and specificity of 73%. Current evidence is largely restricted to the use of phage assays for the detection of rifampicin resistance in culture isolates. When used on culture isolates, these assays appear to have high sensitivity, but variable and slightly lower specificity. In contrast, evidence is lacking on the accuracy of these assays when they are directly applied to sputum specimens. If phage-based assays can be directly used on clinical specimens and if they are shown to have high accuracy, they have the potential to improve the diagnosis of MDR-TB. However, before phage assays can be successfully used in routine practice, several concerns have to be addressed, including unexplained false positives in some studies, potential for contamination and indeterminate results.

Prospective trial evaluating the sensitivity and specificity of 3,4-dihydroxy-6-[18F]-fluoro-L-phenylalanine (18F-DOPA) PET and MRI in patients with recurrent gliomas.

PubMed

Youland, Ryan S; Pafundi, Deanna H; Brinkmann, Debra H; Lowe, Val J; Morris, Jonathan M; Kemp, Bradley J; Hunt, Christopher H; Giannini, Caterina; Parney, Ian F; Laack, Nadia N

2018-05-01

Treatment-related changes can be difficult to differentiate from progressive glioma using MRI with contrast (CE). The purpose of this study is to compare the sensitivity and specificity of 18F-DOPA-PET and MRI in patients with recurrent glioma. Thirteen patients with MRI findings suspicious for recurrent glioma were prospectively enrolled and underwent 18F-DOPA-PET and MRI for neurosurgical planning. Stereotactic biopsies were obtained from regions of concordant and discordant PET and MRI CE, all within regions of T2/FLAIR signal hyperintensity. The sensitivity and specificity of 18F-DOPA-PET and CE were calculated based on histopathologic analysis. Receiver operating characteristic curve analysis revealed optimal tumor to normal (T/N) and SUVmax thresholds. In the 37 specimens obtained, 51% exhibited MRI contrast enhancement (M+) and 78% demonstrated 18F-DOPA-PET avidity (P+). Imaging characteristics included M-P- in 16%, M-P+ in 32%, M+P+ in 46% and M+P- in 5%. Histopathologic review of biopsies revealed grade II components in 16%, grade III in 43%, grade IV in 30% and no tumor in 11%. MRI CE sensitivity for recurrent tumor was 52% and specificity was 50%. PET sensitivity for tumor was 82% and specificity was 50%. A T/N threshold > 2.0 altered sensitivity to 76% and specificity to 100% and SUVmax > 1.36 improved sensitivity and specificity to 94 and 75%, respectively. 18F-DOPA-PET can provide increased sensitivity and specificity compared with MRI CE for visualizing the spatial distribution of recurrent gliomas. Future studies will incorporate 18F-DOPA-PET into re-irradiation target volume delineation for RT planning.

Blinded study determination of high sensitivity and specificity microchip electrophoresis–SSCP/HA to detect mutations in the p53 gene

PubMed Central

Hestekin, Christa N.; Lin, Jennifer S.; Senderowicz, Lionel; Jakupciak, John P.; O’Connell, Catherine; Rademaker, Alfred; Barron, Annelise E.

2012-01-01

Knowledge of the genetic changes that lead to disease has grown and continues to grow at a rapid pace. However, there is a need for clinical devices that can be used routinely to translate this knowledge into the treatment of patients. Use in a clinical setting requires high sensitivity and specificity (>97%) in order to prevent misdiagnoses. Single strand conformational polymorphism (SSCP) and heteroduplex analysis (HA) are two DNA-based, complementary methods for mutation detection that are inexpensive and relatively easy to implement. However, both methods are most commonly detected by slab gel electrophoresis, which can be labor-intensive, time-consuming, and often the methods are unable to produce high sensitivity and specificity without the use of multiple analysis conditions. Here we demonstrate the first blinded study using microchip electrophoresis-SSCP/HA. We demonstrate the ability of microchip electrophoresis-SSCP/HA to detect with 98% sensitivity and specificity >100 samples from the p53 gene exons 5–9 in a blinded study in an analysis time of less than 10 minutes. PMID:22002021

Diagnostic value of highly-sensitive chimerism analysis after allogeneic stem cell transplantation.

PubMed

Sellmann, Lea; Rabe, Kim; Bünting, Ivonne; Dammann, Elke; Göhring, Gudrun; Ganser, Arnold; Stadler, Michael; Weissinger, Eva M; Hambach, Lothar

2018-05-02

Conventional analysis of host chimerism (HC) frequently fails to detect relapse before its clinical manifestation in patients with hematological malignancies after allogeneic stem cell transplantation (allo-SCT). Quantitative PCR (qPCR)-based highly-sensitive chimerism analysis extends the detection limit of conventional (short tandem repeats-based) chimerism analysis from 1 to 0.01% host cells in whole blood. To date, the diagnostic value of highly-sensitive chimerism analysis is hardly defined. Here, we applied qPCR-based chimerism analysis to 901 blood samples of 71 out-patients with hematological malignancies after allo-SCT. Receiver operating characteristics (ROC) curves were calculated for absolute HC values and for the increments of HC before relapse. Using the best cut-offs, relapse was detected with sensitivities of 74 or 85% and specificities of 69 or 75%, respectively. Positive predictive values (PPVs) were only 12 or 18%, but the respective negative predictive values were 98 or 99%. Relapse was detected median 38 or 45 days prior to clinical diagnosis, respectively. Considering also durations of steadily increasing HC of more than 28 days improved PPVs to more than 28 or 59%, respectively. Overall, highly-sensitive chimerism analysis excludes relapses with high certainty and predicts relapses with high sensitivity and specificity more than a month prior to clinical diagnosis.

Competitive amplification of differentially melting amplicons (CADMA) enables sensitive and direct detection of all mutation types by high-resolution melting analysis.

PubMed

Kristensen, Lasse S; Andersen, Gitte B; Hager, Henrik; Hansen, Lise Lotte

2012-01-01

Sensitive and specific mutation detection is of particular importance in cancer diagnostics, prognostics, and individualized patient treatment. However, the majority of molecular methodologies that have been developed with the aim of increasing the sensitivity of mutation testing have drawbacks in terms of specificity, convenience, or costs. Here, we have established a new method, Competitive Amplification of Differentially Melting Amplicons (CADMA), which allows very sensitive and specific detection of all mutation types. The principle of the method is to amplify wild-type and mutated sequences simultaneously using a three-primer system. A mutation-specific primer is designed to introduce melting temperature decreasing mutations in the resulting mutated amplicon, while a second overlapping primer is designed to amplify both wild-type and mutated sequences. When combined with a third common primer very sensitive mutation detection becomes possible, when using high-resolution melting (HRM) as detection platform. The introduction of melting temperature decreasing mutations in the mutated amplicon also allows for further mutation enrichment by fast coamplification at lower denaturation temperature PCR (COLD-PCR). For proof-of-concept, we have designed CADMA assays for clinically relevant BRAF, EGFR, KRAS, and PIK3CA mutations, which are sensitive to, between 0.025% and 0.25%, mutated alleles in a wild-type background. In conclusion, CADMA enables highly sensitive and specific mutation detection by HRM analysis. © 2011 Wiley Periodicals, Inc.

Univariate and bivariate likelihood-based meta-analysis methods performed comparably when marginal sensitivity and specificity were the targets of inference.

PubMed

Dahabreh, Issa J; Trikalinos, Thomas A; Lau, Joseph; Schmid, Christopher H

2017-03-01

To compare statistical methods for meta-analysis of sensitivity and specificity of medical tests (e.g., diagnostic or screening tests). We constructed a database of PubMed-indexed meta-analyses of test performance from which 2 × 2 tables for each included study could be extracted. We reanalyzed the data using univariate and bivariate random effects models fit with inverse variance and maximum likelihood methods. Analyses were performed using both normal and binomial likelihoods to describe within-study variability. The bivariate model using the binomial likelihood was also fit using a fully Bayesian approach. We use two worked examples-thoracic computerized tomography to detect aortic injury and rapid prescreening of Papanicolaou smears to detect cytological abnormalities-to highlight that different meta-analysis approaches can produce different results. We also present results from reanalysis of 308 meta-analyses of sensitivity and specificity. Models using the normal approximation produced sensitivity and specificity estimates closer to 50% and smaller standard errors compared to models using the binomial likelihood; absolute differences of 5% or greater were observed in 12% and 5% of meta-analyses for sensitivity and specificity, respectively. Results from univariate and bivariate random effects models were similar, regardless of estimation method. Maximum likelihood and Bayesian methods produced almost identical summary estimates under the bivariate model; however, Bayesian analyses indicated greater uncertainty around those estimates. Bivariate models produced imprecise estimates of the between-study correlation of sensitivity and specificity. Differences between methods were larger with increasing proportion of studies that were small or required a continuity correction. The binomial likelihood should be used to model within-study variability. Univariate and bivariate models give similar estimates of the marginal distributions for sensitivity and specificity. Bayesian methods fully quantify uncertainty and their ability to incorporate external evidence may be useful for imprecisely estimated parameters. Copyright © 2017 Elsevier Inc. All rights reserved.

Performance of the dipstick screening test as a predictor of negative urine culture

PubMed Central

Marques, Alexandre Gimenes; Doi, André Mario; Pasternak, Jacyr; Damascena, Márcio dos Santos; França, Carolina Nunes; Martino, Marinês Dalla Valle

2017-01-01

ABSTRACT Objective To investigate whether the urine dipstick screening test can be used to predict urine culture results. Methods A retrospective study conducted between January and December 2014 based on data from 8,587 patients with a medical order for urine dipstick test, urine sediment analysis and urine culture. Sensitivity, specificity, positive and negative predictive values were determined and ROC curve analysis was performed. Results The percentage of positive cultures was 17.5%. Nitrite had 28% sensitivity and 99% specificity, with positive and negative predictive values of 89% and 87%, respectively. Leukocyte esterase had 79% sensitivity and 84% specificity, with positive and negative predictive values of 51% and 95%, respectively. The combination of positive nitrite or positive leukocyte esterase tests had 85% sensitivity and 84% specificity, with positive and negative predictive values of 53% and 96%, respectively. Positive urinary sediment (more than ten leukocytes per microliter) had 92% sensitivity and 71% specificity, with positive and negative predictive values of 40% and 98%, respectively. The combination of nitrite positive test and positive urinary sediment had 82% sensitivity and 99% specificity, with positive and negative predictive values of 91% and 98%, respectively. The combination of nitrite or leukocyte esterase positive tests and positive urinary sediment had the highest sensitivity (94%) and specificity (84%), with positive and negative predictive values of 58% and 99%, respectively. Based on ROC curve analysis, the best indicator of positive urine culture was the combination of positives leukocyte esterase or nitrite tests and positive urinary sediment, followed by positives leukocyte and nitrite tests, positive urinary sediment alone, positive leukocyte esterase test alone, positive nitrite test alone and finally association of positives nitrite and urinary sediment (AUC: 0.845, 0.844, 0.817, 0.814, 0.635 and 0.626, respectively). Conclusion A negative urine culture can be predicted by negative dipstick test results. Therefore, this test may be a reliable predictor of negative urine culture. PMID:28444086

Diagnostic Accuracy of Memory Measures in Alzheimer's Dementia and Mild Cognitive Impairment: a Systematic Review and Meta-Analysis.

PubMed

Weissberger, Gali H; Strong, Jessica V; Stefanidis, Kayla B; Summers, Mathew J; Bondi, Mark W; Stricker, Nikki H

2017-12-01

With an increasing focus on biomarkers in dementia research, illustrating the role of neuropsychological assessment in detecting mild cognitive impairment (MCI) and Alzheimer's dementia (AD) is important. This systematic review and meta-analysis, conducted in accordance with PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) standards, summarizes the sensitivity and specificity of memory measures in individuals with MCI and AD. Both meta-analytic and qualitative examination of AD versus healthy control (HC) studies (n = 47) revealed generally high sensitivity and specificity (≥ 80% for AD comparisons) for measures of immediate (sensitivity = 87%, specificity = 88%) and delayed memory (sensitivity = 89%, specificity = 89%), especially those involving word-list recall. Examination of MCI versus HC studies (n = 38) revealed generally lower diagnostic accuracy for both immediate (sensitivity = 72%, specificity = 81%) and delayed memory (sensitivity = 75%, specificity = 81%). Measures that differentiated AD from other conditions (n = 10 studies) yielded mixed results, with generally high sensitivity in the context of low or variable specificity. Results confirm that memory measures have high diagnostic accuracy for identification of AD, are promising but require further refinement for identification of MCI, and provide support for ongoing investigation of neuropsychological assessment as a cognitive biomarker of preclinical AD. Emphasizing diagnostic test accuracy statistics over null hypothesis testing in future studies will promote the ongoing use of neuropsychological tests as Alzheimer's disease research and clinical criteria increasingly rely upon cerebrospinal fluid (CSF) and neuroimaging biomarkers.

Sensitivity and Specificity of CT and Its signs for Diagnosis of Strangulation in Patients with Acute Small Bowel Obstruction.

PubMed

Jha, Ashwini Kumar; Tang, Wen Hao; Bai, Zhi Bin; Xiao, Jia Quan

2014-01-01

To perform a meta-analysis to review the sensitivity and specificity of computed tomography and different known computed yomography signs for the diagnosis of strangulation in patients with acute small bowel obstruction. A comprehensive Pubmed search was performed for all reports that evaluated the use of CT and discussed different CT criteria for the diagnosis of acute SBO. Articles published in English language from January 1978 to June 2008 were included. Review articles, case reports, pictorial essays and articles without original data were excluded. The bivariate random effect model was used to obtain pooled sensitivity and pooled specificity. Summary receiver operating curve was calculated using Meta-Disc. Software Openbugs 3.0.3 was used to summarize the data. A total of 12 studies fulfilled the inclusion criteria. The pooled sensitivity and specificity of CT in the diagnosis of strangulation was 0.720 (95% CI 0.674 to 0.763) and 0.866 (95% CI 0.837 to 0.892) respectively. Among different CT signs, mesenteric edema had highest Pooled sensitivity of 0. 741 and lack of bowel wall enhancement had highest pooled specificity of 0.991. This review demonstrates that CT is highly sensitive as well as specific in the preoperative diagnosis of strangulation SBO which are in accordance with the published studies. Our analysis also shows that "presence of mesenteric fluid" is most sensitive, and "lack of bowel wall enhancement" is most specific CT sign of strangulation, and also justifies need of large scale prospective studies to validate the results obtained as well as to determine a clinical protocol.

Colonic lesion characterization in inflammatory bowel disease: A systematic review and meta-analysis

PubMed Central

Lord, Richard; Burr, Nicholas E; Mohammed, Noor; Subramanian, Venkataraman

2018-01-01

AIM To perform a systematic review and meta-analysis for the diagnostic accuracy of in vivo lesion characterization in colonic inflammatory bowel disease (IBD), using optical imaging techniques, including virtual chromoendoscopy (VCE), dye-based chromoendoscopy (DBC), magnification endoscopy and confocal laser endomicroscopy (CLE). METHODS We searched Medline, Embase and the Cochrane library. We performed a bivariate meta-analysis to calculate the pooled estimate sensitivities, specificities, positive and negative likelihood ratios (+LHR, -LHR), diagnostic odds ratios (DOR), and area under the SROC curve (AUSROC) for each technology group. A subgroup analysis was performed to investigate differences in real-time non-magnified Kudo pit patterns (with VCE and DBC) and real-time CLE. RESULTS We included 22 studies [1491 patients; 4674 polyps, of which 539 (11.5%) were neoplastic]. Real-time CLE had a pooled sensitivity of 91% (95%CI: 66%-98%), specificity of 97% (95%CI: 94%-98%), and an AUSROC of 0.98 (95%CI: 0.97-0.99). Magnification endoscopy had a pooled sensitivity of 90% (95%CI: 77%-96%) and specificity of 87% (95%CI: 81%-91%). VCE had a pooled sensitivity of 86% (95%CI: 62%-95%) and specificity of 87% (95%CI: 72%-95%). DBC had a pooled sensitivity of 67% (95%CI: 44%-84%) and specificity of 86% (95%CI: 72%-94%). CONCLUSION Real-time CLE is a highly accurate technology for differentiating neoplastic from non-neoplastic lesions in patients with colonic IBD. However, most CLE studies were performed by single expert users within tertiary centres, potentially confounding these results. PMID:29563760

Diagnostic accuracy of the aspartate aminotransferase-to-platelet ratio index for the prediction of hepatitis B-related fibrosis: a leading meta-analysis

PubMed Central

2012-01-01

Background The aspartate aminotransferase-to-platelet ratio index (APRI), a tool with limited expense and widespread availability, is a promising noninvasive alternative to liver biopsy for detecting hepatic fibrosis. The objective of this study was to systematically review the performance of the APRI in predicting significant fibrosis and cirrhosis in hepatitis B-related fibrosis. Methods Areas under summary receiver operating characteristic curves (AUROC), sensitivity and specificity were used to examine the accuracy of the APRI for the diagnosis of hepatitis B-related significant fibrosis and cirrhosis. Heterogeneity was explored using meta-regression. Results Nine studies were included in this meta-analysis (n = 1,798). Prevalence of significant fibrosis and cirrhosis were 53.1% and 13.5%, respectively. The summary AUCs of the APRI for significant fibrosis and cirrhosis were 0.79 and 0.75, respectively. For significant fibrosis, an APRI threshold of 0.5 was 84% sensitive and 41% specific. At the cutoff of 1.5, the summary sensitivity and specificity were 49% and 84%, respectively. For cirrhosis, an APRI threshold of 1.0-1.5 was 54% sensitive and 78% specific. At the cutoff of 2.0, the summary sensitivity and specificity were 28% and 87%, respectively. Meta-regression analysis indicated that the APRI accuracy for both significant fibrosis and cirrhosis was affected by histological classification systems, but not influenced by the interval between Biopsy & APRI or blind biopsy. Conclusion Our meta-analysis suggests that APRI show limited value in identifying hepatitis B-related significant fibrosis and cirrhosis. PMID:22333407

Determination of IgE antibodies to the benzylpenicilloyl determinant: a comparison of the sensitivity and specificity of three radio allergo sorbent test methods.

PubMed

Garcia, J J; Blanca, M; Moreno, F; Vega, J M; Mayorga, C; Fernandez, J; Juarez, C; Romano, A; de Ramon, E

1997-01-01

The quantitation of in vitro IgE antibodies to the benzylpenicilloyl determinant (BPO) is a useful tool for evaluating suspected penicillin allergic subjects. Although many different methods have been employed, few studies have compared their diagnostic specificity and sensitivity. In this study, the sensitivity and specificity of three different radio allergo sorbent test (RAST) methods for quantitating specific IgE antibodies to the BPO determinant were compared. Thirty positive control sera (serum samples from penicillin allergic subjects with a positive clinical history and a positive penicillin skin test) and 30 negative control sera (sera from subjects with no history of penicillin allergy and negative skin tests) were tested for BPO-specific IgE antibodies by RAST using three different conjugates coupled to the solid phase: benzylpenicillin conjugated to polylysine (BPO-PLL), benzylpenicillin conjugated to human serum albumin (BPO-HSA), and benzylpenicillin conjugated to an aminospacer (BPO-SP). Receiver operator control curves (ROC analysis) were carried out by determining different cut-off points between positive and negative values. Contingence tables were constructed and sensitivity, specificity, negative predictive values (PV-), and positive predictive values (PV+) were calculated. Pearson correlation coefficients (r) and intraclass correlation coefficients (ICC) were determined and the differences between methods were compared by chi 2 analysis. Analysis of the areas defined by the ROC curves showed statistical differences among the three methods. When cut-off points for optimal sensitivity and specificity were chosen, the BPO-HSA assay was less sensitive and less specific and had a lower PV- and PV+ than the BPO-PLL and BPO-SP assays. Assessment of r and ICC indicated that the correlation was very high, but the concordance between the PLL and SP methods was higher than between the PLL and HSA or SP and HSA methods. We conclude that for quantitating IgE antibodies by RAST to the BPO determinant, BPO-SP or BPO-PLL conjugates offer advantages in sensitivity and specificity compared with BPO-HSA. These results support and extend previous in vitro studies by our group and highlight the importance of the carrier for RAST assays.

Increased sensitivity of prolonged P-wave during exercise stress test in detection of angiographically documented coronary artery disease.

PubMed

Wsol, Agnieszka; Wydra, Wioletta; Chmielewski, Marek; Swiatowiec, Andrzej; Kuch, Marek

2017-01-01

A retrospective study was designed to investigate P-wave duration changes in exercise stress test (EST) for the prediction of angiographically documented substantial coronary artery disease (CAD). We analyzed 265 cases of patients, who underwent EST and subsequently coronary angiography. Analysis of P-wave duration was performed in leads II, V5 at rest, and in the recovery period. The sensitivity and specificity for the isolated ST-segment depression were only 31% and 76%, respectively. The combination of ST-depression with other exercise-induced clinical and electrocardio-graphic abnormalities (chest pain, ventricular arrhythmia, hypotension, left bundle branch block) was characterized by 41% sensitivity and 69% specificity. The combination of abnormal recovery P-wave duration (≥ 120 ms) with ST-depression and other exercise-induced abnormalities had 83% sensitivity but only 20% specificity. Combined analysis of increased delta P-wave duration, ST-depression and other exercise-induced abnormalities had 69% sensitivity and 42% specificity. Sensitivity and specificity of the increase in delta P-wave duration for left CAD was 69% and 47%, respectively, and for 3-vessel CAD 70% and 50%, respectively. The presence of arterial hypertension negatively influenced the prog-nostic value of P-wave changes in the stress test. The results of the study show that an addition of P-wave duration changes assessment to ST-depression analysis and other exercise-induced abnormalities increase sensitivity of EST, especially for left CAD and 3-vessel coronary disease. We have also provided evidence for the negative influence of the presence of arterial hypertension on the predictive value of P-wave changes in the stress test. (Cardiol J 2017; 24, 2: 159-166).

Variation of a test's sensitivity and specificity with disease prevalence.

PubMed

Leeflang, Mariska M G; Rutjes, Anne W S; Reitsma, Johannes B; Hooft, Lotty; Bossuyt, Patrick M M

2013-08-06

Anecdotal evidence suggests that the sensitivity and specificity of a diagnostic test may vary with disease prevalence. Our objective was to investigate the associations between disease prevalence and test sensitivity and specificity using studies of diagnostic accuracy. We used data from 23 meta-analyses, each of which included 10-39 studies (416 total). The median prevalence per review ranged from 1% to 77%. We evaluated the effects of prevalence on sensitivity and specificity using a bivariate random-effects model for each meta-analysis, with prevalence as a covariate. We estimated the overall effect of prevalence by pooling the effects using the inverse variance method. Within a given review, a change in prevalence from the lowest to highest value resulted in a corresponding change in sensitivity or specificity from 0 to 40 percentage points. This effect was statistically significant (p < 0.05) for either sensitivity or specificity in 8 meta-analyses (35%). Overall, specificity tended to be lower with higher disease prevalence; there was no such systematic effect for sensitivity. The sensitivity and specificity of a test often vary with disease prevalence; this effect is likely to be the result of mechanisms, such as patient spectrum, that affect prevalence, sensitivity and specificity. Because it may be difficult to identify such mechanisms, clinicians should use prevalence as a guide when selecting studies that most closely match their situation.

Variation of a test’s sensitivity and specificity with disease prevalence

PubMed Central

Leeflang, Mariska M.G.; Rutjes, Anne W.S.; Reitsma, Johannes B.; Hooft, Lotty; Bossuyt, Patrick M.M.

2013-01-01

Background: Anecdotal evidence suggests that the sensitivity and specificity of a diagnostic test may vary with disease prevalence. Our objective was to investigate the associations between disease prevalence and test sensitivity and specificity using studies of diagnostic accuracy. Methods: We used data from 23 meta-analyses, each of which included 10–39 studies (416 total). The median prevalence per review ranged from 1% to 77%. We evaluated the effects of prevalence on sensitivity and specificity using a bivariate random-effects model for each meta-analysis, with prevalence as a covariate. We estimated the overall effect of prevalence by pooling the effects using the inverse variance method. Results: Within a given review, a change in prevalence from the lowest to highest value resulted in a corresponding change in sensitivity or specificity from 0 to 40 percentage points. This effect was statistically significant (p < 0.05) for either sensitivity or specificity in 8 meta-analyses (35%). Overall, specificity tended to be lower with higher disease prevalence; there was no such systematic effect for sensitivity. Interpretation: The sensitivity and specificity of a test often vary with disease prevalence; this effect is likely to be the result of mechanisms, such as patient spectrum, that affect prevalence, sensitivity and specificity. Because it may be difficult to identify such mechanisms, clinicians should use prevalence as a guide when selecting studies that most closely match their situation. PMID:23798453

Do We Know Who Will Drop out?: A Review of the Predictors of Dropping out of High School--Precision, Sensitivity, and Specificity

ERIC Educational Resources Information Center

Bowers, Alex J.; Sprott, Ryan; Taff, Sherry A.

2013-01-01

The purpose of this study is to review the literature on the most accurate indicators of students at risk of dropping out of high school. We used Relative Operating Characteristic (ROC) analysis to compare the sensitivity and specificity of 110 dropout flags across 36 studies. Our results indicate that 1) ROC analysis provides a means to compare…

Cardiothoracic ratio for prediction of left ventricular dilation: a systematic review and pooled analysis.

PubMed

Loomba, Rohit S; Shah, Parinda H; Nijhawan, Karan; Aggarwal, Saurabh; Arora, Rohit

2015-03-01

Increased cardiothoracic ratio noted on chest radiographs often prompts concern and further evaluation with additional imaging. This study pools available data assessing the utility of cardiothoracic ratio in predicting left ventricular dilation. A systematic review of the literature was conducted to identify studies comparing cardiothoracic ratio by chest x-ray to left ventricular dilation by echocardiography. Electronic databases were used to identify studies which were then assessed for quality and bias, with those with adequate quality and minimal bias ultimately being included in the pooled analysis. The pooled data were used to determine the sensitivity, specificity, positive predictive value and negative predictive value of cardiomegaly in predicting left ventricular dilation. A total of six studies consisting of 466 patients were included in this analysis. Cardiothoracic ratio had 83.3% sensitivity, 45.4% specificity, 43.5% positive predictive value and 82.7% negative predictive value. When a secondary analysis was conducted with a pediatric study excluded, a total of five studies consisting of 371 patients were included. Cardiothoracic ratio had 86.2% sensitivity, 25.2% specificity, 42.5% positive predictive value and 74.0% negative predictive value. Cardiothoracic ratio as determined by chest radiograph is sensitive but not specific for identifying left ventricular dilation. Cardiothoracic ratio also has a strong negative predictive value for identifying left ventricular dilation.

Diagnostic performance of contrast-enhanced spectral mammography: Systematic review and meta-analysis.

PubMed

Tagliafico, Alberto Stefano; Bignotti, Bianca; Rossi, Federica; Signori, Alessio; Sormani, Maria Pia; Valdora, Francesca; Calabrese, Massimo; Houssami, Nehmat

2016-08-01

To estimate sensitivity and specificity of CESM for breast cancer diagnosis. Systematic review and meta-analysis of the accuracy of CESM in finding breast cancer in highly selected women. We estimated summary receiver operating characteristic curves, sensitivity and specificity according to quality criteria with QUADAS-2. Six hundred four studies were retrieved, 8 of these reporting on 920 patients with 994 lesions, were eligible for inclusion. Estimated sensitivity from all studies was: 0.98 (95% CI: 0.96-1.00). Specificity was estimated from six studies reporting raw data: 0.58 (95% CI: 0.38-0.77). The majority of studies were scored as at high risk of bias due to the very selected populations. CESM has a high sensitivity but very low specificity. The source studies were based on highly selected case series and prone to selection bias. High-quality studies are required to assess the accuracy of CESM in unselected cases. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bayesian Estimation of the True Prevalence and of the Diagnostic Test Sensitivity and Specificity of Enteropathogenic Yersinia in Finnish Pig Serum Samples.

PubMed

Vilar, M J; Ranta, J; Virtanen, S; Korkeala, H

2015-01-01

Bayesian analysis was used to estimate the pig's and herd's true prevalence of enteropathogenic Yersinia in serum samples collected from Finnish pig farms. The sensitivity and specificity of the diagnostic test were also estimated for the commercially available ELISA which is used for antibody detection against enteropathogenic Yersinia. The Bayesian analysis was performed in two steps; the first step estimated the prior true prevalence of enteropathogenic Yersinia with data obtained from a systematic review of the literature. In the second step, data of the apparent prevalence (cross-sectional study data), prior true prevalence (first step), and estimated sensitivity and specificity of the diagnostic methods were used for building the Bayesian model. The true prevalence of Yersinia in slaughter-age pigs was 67.5% (95% PI 63.2-70.9). The true prevalence of Yersinia in sows was 74.0% (95% PI 57.3-82.4). The estimates of sensitivity and specificity values of the ELISA were 79.5% and 96.9%.

Blinded study determination of high sensitivity and specificity microchip electrophoresis-SSCP/HA to detect mutations in the p53 gene.

PubMed

Hestekin, Christa N; Lin, Jennifer S; Senderowicz, Lionel; Jakupciak, John P; O'Connell, Catherine; Rademaker, Alfred; Barron, Annelise E

2011-11-01

Knowledge of the genetic changes that lead to disease has grown and continues to grow at a rapid pace. However, there is a need for clinical devices that can be used routinely to translate this knowledge into the treatment of patients. Use in a clinical setting requires high sensitivity and specificity (>97%) in order to prevent misdiagnoses. Single-strand conformational polymorphism (SSCP) and heteroduplex analysis (HA) are two DNA-based, complementary methods for mutation detection that are inexpensive and relatively easy to implement. However, both methods are most commonly detected by slab gel electrophoresis, which can be labor-intensive, time-consuming, and often the methods are unable to produce high sensitivity and specificity without the use of multiple analysis conditions. Here, we demonstrate the first blinded study using microchip electrophoresis (ME)-SSCP/HA. We demonstrate the ability of ME-SSCP/HA to detect with 98% sensitivity and specificity >100 samples from the p53 gene exons 5-9 in a blinded study in an analysis time of <10 min. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Asymmetric exponential amplification reaction on a toehold/biotin featured template: an ultrasensitive and specific strategy for isothermal microRNAs analysis

PubMed Central

Chen, Jun; Zhou, Xueqing; Ma, Yingjun; Lin, Xiulian; Dai, Zong; Zou, Xiaoyong

2016-01-01

The sensitive and specific analysis of microRNAs (miRNAs) without using a thermal cycler instrument is significant and would greatly facilitate biological research and disease diagnostics. Although exponential amplification reaction (EXPAR) is the most attractive strategy for the isothermal analysis of miRNAs, its intrinsic limitations of detection efficiency and inevitable non-specific amplification critically restrict its use in analytical sensitivity and specificity. Here, we present a novel asymmetric EXPAR based on a new biotin/toehold featured template. A biotin tag was used to reduce the melting temperature of the primer/template duplex at the 5′ terminus of the template, and a toehold exchange structure acted as a filter to suppress the non-specific trigger of EXPAR. The asymmetric EXPAR exhibited great improvements in amplification efficiency and specificity as well as a dramatic extension of dynamic range. The limit of detection for the let-7a analysis was decreased to 6.02 copies (0.01 zmol), and the dynamic range was extended to 10 orders of magnitude. The strategy enabled the sensitive and accurate analysis of let-7a miRNA in human cancer tissues with clearly better precision than both standard EXPAR and RT-qPCR. Asymmetric EXPAR is expected to have an important impact on the development of simple and rapid molecular diagnostic applications for short oligonucleotides. PMID:27257058

Urinary neutrophil gelatinase-associated lipocalin for diagnosis and estimating activity in lupus nephritis: a meta-analysis.

PubMed

Fang, Y G; Chen, N N; Cheng, Y B; Sun, S J; Li, H X; Sun, F; Xiang, Y

2015-12-01

Urinary neutrophil gelatinase-associated lipocalin (uNGAL) is relatively specific in lupus nephritis (LN) patients. However, its diagnostic value has not been evaluated. The aim of this review was to determine the value of uNGAL for diagnosis and estimating activity in LN. A comprehensive search was performed on PubMed, EMBASE, Web of Knowledge, Cochrane electronic databases through December 2014. Meta-analysis of sensitivity and specificity was performed with a random-effects model. Additionally, summary receiver operating characteristic (SROC) curves and area under the curve (AUC) values were calculated. Fourteen studies were selected for this review. With respect to diagnosing LN, the pooled sensitivity and specificity were 73.6% (95% confidence interval (CI), 61.9-83.3) and 78.1% (95% CI, 69.0-85.6), respectively. The SROC-AUC value was 0.8632. Regarding estimating LN activity, the pooled sensitivity and specificity were 66.2% (95% CI, 60.4-71.7) and 62.1% (95% CI, 57.9-66.3), respectively. The SROC-AUC value was 0.7583. In predicting renal flares, the pooled sensitivity and specificity were 77.5% (95% CI, 68.1-85.1) and 65.3% (95% CI, 60.0-70.3), respectively. The SROC-AUC value was 0.7756. In conclusion, this meta-analysis indicates that uNGAL has relatively fair sensitivity and specificity in diagnosing LN, estimating LN activity and predicting renal flares, suggesting that uNGAL is a potential biomarker in diagnosing LN and monitoring LN activity. © The Author(s) 2015.

Optimizing the interpretation of CT for appendicitis: modeling health utilities for clinical practice.

PubMed

Blackmore, C Craig; Terasawa, Teruhiko

2006-02-01

Error in radiology can be reduced by standardizing the interpretation of imaging studies to the optimum sensitivity and specificity. In this report, the authors demonstrate how the optimal interpretation of appendiceal computed tomography (CT) can be determined and how it varies in different clinical scenarios. Utility analysis and receiver operating characteristic (ROC) curve modeling were used to determine the trade-off between false-positive and false-negative test results to determine the optimal operating point on the ROC curve for the interpretation of appendicitis CT. Modeling was based on a previous meta-analysis for the accuracy of CT and on literature estimates of the utilities of various health states. The posttest probability of appendicitis was derived using Bayes's theorem. At a low prevalence of disease (screening), appendicitis CT should be interpreted at high specificity (97.7%), even at the expense of lower sensitivity (75%). Conversely, at a high probability of disease, high sensitivity (97.4%) is preferred (specificity 77.8%). When the clinical diagnosis of appendicitis is equivocal, CT interpretation should emphasize both sensitivity and specificity (sensitivity 92.3%, specificity 91.5%). Radiologists can potentially decrease medical error and improve patient health by varying the interpretation of appendiceal CT on the basis of the clinical probability of appendicitis. This report is an example of how utility analysis can be used to guide radiologists in the interpretation of imaging studies and provide guidance on appropriate targets for the standardization of interpretation.

Meta-analysis of diagnostic accuracy studies in mental health

PubMed Central

Takwoingi, Yemisi; Riley, Richard D; Deeks, Jonathan J

2015-01-01

Objectives To explain methods for data synthesis of evidence from diagnostic test accuracy (DTA) studies, and to illustrate different types of analyses that may be performed in a DTA systematic review. Methods We described properties of meta-analytic methods for quantitative synthesis of evidence. We used a DTA review comparing the accuracy of three screening questionnaires for bipolar disorder to illustrate application of the methods for each type of analysis. Results The discriminatory ability of a test is commonly expressed in terms of sensitivity (proportion of those with the condition who test positive) and specificity (proportion of those without the condition who test negative). There is a trade-off between sensitivity and specificity, as an increasing threshold for defining test positivity will decrease sensitivity and increase specificity. Methods recommended for meta-analysis of DTA studies --such as the bivariate or hierarchical summary receiver operating characteristic (HSROC) model --jointly summarise sensitivity and specificity while taking into account this threshold effect, as well as allowing for between study differences in test performance beyond what would be expected by chance. The bivariate model focuses on estimation of a summary sensitivity and specificity at a common threshold while the HSROC model focuses on the estimation of a summary curve from studies that have used different thresholds. Conclusions Meta-analyses of diagnostic accuracy studies can provide answers to important clinical questions. We hope this article will provide clinicians with sufficient understanding of the terminology and methods to aid interpretation of systematic reviews and facilitate better patient care. PMID:26446042

ADC as a useful diagnostic tool for differentiating benign and malignant vertebral bone marrow lesions and compression fractures: a systematic review and meta-analysis.

PubMed

Suh, Chong Hyun; Yun, Seong Jong; Jin, Wook; Lee, Sun Hwa; Park, So Young; Ryu, Chang-Woo

2018-07-01

To assess the sensitivity and specificity of quantitative assessment of the apparent diffusion coefficient (ADC) for differentiating benign and malignant vertebral bone marrow lesions (BMLs) and compression fractures (CFs) METHODS: An electronic literature search of MEDLINE and EMBASE was conducted. Bivariate modelling and hierarchical summary receiver operating characteristic modelling were performed to evaluate the diagnostic performance of ADC for differentiating vertebral BMLs. Subgroup analysis was performed for differentiating benign and malignant vertebral CFs. Meta-regression analyses according to subject, study and diffusion-weighted imaging (DWI) characteristics were performed. Twelve eligible studies (748 lesions, 661 patients) were included. The ADC exhibited a pooled sensitivity of 0.89 (95% confidence interval [CI] 0.80-0.94) and a pooled specificity of 0.87 (95% CI 0.78-0.93) for differentiating benign and malignant vertebral BMLs. In addition, the pooled sensitivity and specificity for differentiating benign and malignant CFs were 0.92 (95% CI 0.82-0.97) and 0.91 (95% CI 0.87-0.94), respectively. In the meta-regression analysis, the DWI slice thickness was a significant factor affecting heterogeneity (p < 0.01); thinner slice thickness (< 5 mm) showed higher specificity (95%) than thicker slice thickness (81%). Quantitative assessment of ADC is a useful diagnostic tool for differentiating benign and malignant vertebral BMLs and CFs. • Quantitative assessment of ADC is useful in differentiating vertebral BMLs. • Quantitative ADC assessment for BMLs had sensitivity of 89%, specificity of 87%. • Quantitative ADC assessment for CFs had sensitivity of 92%, specificity of 91%. • The specificity is highest (95%) with thinner (< 5 mm) DWI slice thickness.

Sensitivity and specificity of CT colonography for the detection of colonic neoplasia after positive faecal occult blood testing: systematic review and meta-analysis.

PubMed

Plumb, Andrew A; Halligan, Steve; Pendsé, Douglas A; Taylor, Stuart A; Mallett, Susan

2014-05-01

CT colonography (CTC) is recommended after positive faecal occult blood testing (FOBt) when colonoscopy is incomplete or infeasible. We aimed to estimate the sensitivity and specificity of CTC for colorectal cancer and adenomatous polyps following positive FOBt via systematic review. The MEDLINE, EMBASE, AMED and Cochrane Library databases were searched for CTC studies reporting sensitivity and specificity for colorectal cancer and adenomatous polyps. Included subjects had tested FOBt-positive by guaiac or immunochemical methods. Per-patient detection rates were summarized via forest plots. Meta-analysis of sensitivity and specificity was conducted using a bivariate random effects model and the average operating point calculated. Of 538 articles considered, 5 met inclusion criteria, describing results from 622 patients. Research study quality was good. CTC had a high per-patient average sensitivity of 88.8 % (95 % CI 83.6 to 92.5 %) for ≥6 mm adenomas or colorectal cancer, with low between-study heterogeneity. Specificity was both more heterogeneous and lower, at an average of 75.4 % (95 % CI 58.6 to 86.8 %). Few studies have investigated CTC in FOBt-positive individuals. CTC is sensitive at a ≥6 mm threshold but specificity is lower and variable. Despite the limited data, these results suggest that CTC may adequately substitute for colonoscopy when the latter is undesirable. • FOBt is the most common mass screening test for colorectal cancer. • Few studies evaluate CT colonography after positive FOBt. • CTC is approximately 89 % sensitive for ≥6 mm adenomas/cancer in this setting. • Specificity is lower, at approximately 75 %, and more variable. • CT colonography is a good alternative when colonoscopy is undesirable.

Population and High-Risk Group Screening for Glaucoma: The Los Angeles Latino Eye Study

PubMed Central

Francis, Brian A.; Vigen, Cheryl; Lai, Mei-Ying; Winarko, Jonathan; Nguyen, Betsy; Azen, Stanley

2011-01-01

Purpose. To evaluate the ability of various screening tests, both individually and in combination, to detect glaucoma in the general Latino population and high-risk subgroups. Methods. The Los Angeles Latino Eye Study is a population-based study of eye disease in Latinos 40 years of age and older. Participants (n = 6082) underwent Humphrey visual field testing (HVF), frequency doubling technology (FDT) perimetry, measurement of intraocular pressure (IOP) and central corneal thickness (CCT), and independent assessment of optic nerve vertical cup disc (C/D) ratio. Screening parameters were evaluated for three definitions of glaucoma based on optic disc, visual field, and a combination of both. Analyses were also conducted for high-risk subgroups (family history of glaucoma, diabetes mellitus, and age ≥65 years). Sensitivity, specificity, and receiver operating characteristic curves were calculated for those continuous parameters independently associated with glaucoma. Classification and regression tree (CART) analysis was used to develop a multivariate algorithm for glaucoma screening. Results. Preset cutoffs for screening parameters yielded a generally poor balance of sensitivity and specificity (sensitivity/specificity for IOP ≥21 mm Hg and C/D ≥0.8 was 0.24/0.97 and 0.60/0.98, respectively). Assessment of high-risk subgroups did not improve the sensitivity/specificity of individual screening parameters. A CART analysis using multiple screening parameters—C/D, HVF, and IOP—substantially improved the balance of sensitivity and specificity (sensitivity/specificity 0.92/0.92). Conclusions. No single screening parameter is useful for glaucoma screening. However, a combination of vertical C/D ratio, HVF, and IOP provides the best balance of sensitivity/specificity and is likely to provide the highest yield in glaucoma screening programs. PMID:21245400

Sensitivity analysis of the add-on price estimate for the edge-defined film-fed growth process

NASA Technical Reports Server (NTRS)

Mokashi, A. R.; Kachare, A. H.

1981-01-01

The analysis is in terms of cost parameters and production parameters. The cost parameters include equipment, space, direct labor, materials, and utilities. The production parameters include growth rate, process yield, and duty cycle. A computer program was developed specifically to do the sensitivity analysis.

Validation of a next-generation sequencing assay for clinical molecular oncology.

PubMed

Cottrell, Catherine E; Al-Kateb, Hussam; Bredemeyer, Andrew J; Duncavage, Eric J; Spencer, David H; Abel, Haley J; Lockwood, Christina M; Hagemann, Ian S; O'Guin, Stephanie M; Burcea, Lauren C; Sawyer, Christopher S; Oschwald, Dayna M; Stratman, Jennifer L; Sher, Dorie A; Johnson, Mark R; Brown, Justin T; Cliften, Paul F; George, Bijoy; McIntosh, Leslie D; Shrivastava, Savita; Nguyen, Tudung T; Payton, Jacqueline E; Watson, Mark A; Crosby, Seth D; Head, Richard D; Mitra, Robi D; Nagarajan, Rakesh; Kulkarni, Shashikant; Seibert, Karen; Virgin, Herbert W; Milbrandt, Jeffrey; Pfeifer, John D

2014-01-01

Currently, oncology testing includes molecular studies and cytogenetic analysis to detect genetic aberrations of clinical significance. Next-generation sequencing (NGS) allows rapid analysis of multiple genes for clinically actionable somatic variants. The WUCaMP assay uses targeted capture for NGS analysis of 25 cancer-associated genes to detect mutations at actionable loci. We present clinical validation of the assay and a detailed framework for design and validation of similar clinical assays. Deep sequencing of 78 tumor specimens (≥ 1000× average unique coverage across the capture region) achieved high sensitivity for detecting somatic variants at low allele fraction (AF). Validation revealed sensitivities and specificities of 100% for detection of single-nucleotide variants (SNVs) within coding regions, compared with SNP array sequence data (95% CI = 83.4-100.0 for sensitivity and 94.2-100.0 for specificity) or whole-genome sequencing (95% CI = 89.1-100.0 for sensitivity and 99.9-100.0 for specificity) of HapMap samples. Sensitivity for detecting variants at an observed 10% AF was 100% (95% CI = 93.2-100.0) in HapMap mixes. Analysis of 15 masked specimens harboring clinically reported variants yielded concordant calls for 13/13 variants at AF of ≥ 15%. The WUCaMP assay is a robust and sensitive method to detect somatic variants of clinical significance in molecular oncology laboratories, with reduced time and cost of genetic analysis allowing for strategic patient management. Copyright © 2014 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

Sensitivity, Specificity, and Posttest Probability of Parotid Fine-Needle Aspiration: A Systematic Review and Meta-analysis.

PubMed

Liu, C Carrie; Jethwa, Ashok R; Khariwala, Samir S; Johnson, Jonas; Shin, Jennifer J

2016-01-01

(1) To analyze the sensitivity and specificity of fine-needle aspiration (FNA) in distinguishing benign from malignant parotid disease. (2) To determine the anticipated posttest probability of malignancy and probability of nondiagnostic and indeterminate cytology with parotid FNA. Independently corroborated computerized searches of PubMed, Embase, and Cochrane Central Register were performed. These were supplemented with manual searches and input from content experts. Inclusion/exclusion criteria specified diagnosis of parotid mass, intervention with both FNA and surgical excision, and enumeration of both cytologic and surgical histopathologic results. The primary outcomes were sensitivity, specificity, and posttest probability of malignancy. Heterogeneity was evaluated with the I(2) statistic. Meta-analysis was performed via a 2-level mixed logistic regression model. Bayesian nomograms were plotted via pooled likelihood ratios. The systematic review yielded 70 criterion-meeting studies, 63 of which contained data that allowed for computation of numerical outcomes (n = 5647 patients; level 2a) and consideration of meta-analysis. Subgroup analyses were performed in studies that were prospective, involved consecutive patients, described the FNA technique utilized, and used ultrasound guidance. The I(2) point estimate was >70% for all analyses, except within prospectively obtained and ultrasound-guided results. Among the prospective subgroup, the pooled analysis demonstrated a sensitivity of 0.882 (95% confidence interval [95% CI], 0.509-0.982) and a specificity of 0.995 (95% CI, 0.960-0.999). The probabilities of nondiagnostic and indeterminate cytology were 0.053 (95% CI, 0.030-0.075) and 0.147 (95% CI, 0.106-0.188), respectively. FNA has moderate sensitivity and high specificity in differentiating malignant from benign parotid lesions. Considerable heterogeneity is present among studies. © American Academy of Otolaryngology-Head and Neck Surgery Foundation 2015.

Sensitivity, Specificity, and Posttest Probability of Parotid Fine-Needle Aspiration: A Systematic Review and Meta-analysis

PubMed Central

Liu, C. Carrie; Jethwa, Ashok R.; Khariwala, Samir S.; Johnson, Jonas; Shin, Jennifer J.

2016-01-01

Objectives (1) To analyze the sensitivity and specificity of fine-needle aspiration (FNA) in distinguishing benign from malignant parotid disease. (2) To determine the anticipated posttest probability of malignancy and probability of non-diagnostic and indeterminate cytology with parotid FNA. Data Sources Independently corroborated computerized searches of PubMed, Embase, and Cochrane Central Register were performed. These were supplemented with manual searches and input from content experts. Review Methods Inclusion/exclusion criteria specified diagnosis of parotid mass, intervention with both FNA and surgical excision, and enumeration of both cytologic and surgical histopathologic results. The primary outcomes were sensitivity, specificity, and posttest probability of malignancy. Heterogeneity was evaluated with the I2 statistic. Meta-analysis was performed via a 2-level mixed logistic regression model. Bayesian nomograms were plotted via pooled likelihood ratios. Results The systematic review yielded 70 criterion-meeting studies, 63 of which contained data that allowed for computation of numerical outcomes (n = 5647 patients; level 2a) and consideration of meta-analysis. Subgroup analyses were performed in studies that were prospective, involved consecutive patients, described the FNA technique utilized, and used ultrasound guidance. The I2 point estimate was >70% for all analyses, except within prospectively obtained and ultrasound-guided results. Among the prospective subgroup, the pooled analysis demonstrated a sensitivity of 0.882 (95% confidence interval [95% CI], 0.509–0.982) and a specificity of 0.995 (95% CI, 0.960–0.999). The probabilities of nondiagnostic and indeterminate cytology were 0.053 (95% CI, 0.030–0.075) and 0.147 (95% CI, 0.106–0.188), respectively. Conclusion FNA has moderate sensitivity and high specificity in differentiating malignant from benign parotid lesions. Considerable heterogeneity is present among studies. PMID:26428476

Diagnostic accuracy of magnetic resonance imaging techniques for treatment response evaluation in patients with high-grade glioma, a systematic review and meta-analysis.

PubMed

van Dijken, Bart R J; van Laar, Peter Jan; Holtman, Gea A; van der Hoorn, Anouk

2017-10-01

Treatment response assessment in high-grade gliomas uses contrast enhanced T1-weighted MRI, but is unreliable. Novel advanced MRI techniques have been studied, but the accuracy is not well known. Therefore, we performed a systematic meta-analysis to assess the diagnostic accuracy of anatomical and advanced MRI for treatment response in high-grade gliomas. Databases were searched systematically. Study selection and data extraction were done by two authors independently. Meta-analysis was performed using a bivariate random effects model when ≥5 studies were included. Anatomical MRI (five studies, 166 patients) showed a pooled sensitivity and specificity of 68% (95%CI 51-81) and 77% (45-93), respectively. Pooled apparent diffusion coefficients (seven studies, 204 patients) demonstrated a sensitivity of 71% (60-80) and specificity of 87% (77-93). DSC-perfusion (18 studies, 708 patients) sensitivity was 87% (82-91) with a specificity of 86% (77-91). DCE-perfusion (five studies, 207 patients) sensitivity was 92% (73-98) and specificity was 85% (76-92). The sensitivity of spectroscopy (nine studies, 203 patients) was 91% (79-97) and specificity was 95% (65-99). Advanced techniques showed higher diagnostic accuracy than anatomical MRI, the highest for spectroscopy, supporting the use in treatment response assessment in high-grade gliomas. • Treatment response assessment in high-grade gliomas with anatomical MRI is unreliable • Novel advanced MRI techniques have been studied, but diagnostic accuracy is unknown • Meta-analysis demonstrates that advanced MRI showed higher diagnostic accuracy than anatomical MRI • Highest diagnostic accuracy for spectroscopy and perfusion MRI • Supports the incorporation of advanced MRI in high-grade glioma treatment response assessment.

Accuracy of computed tomographic features in differentiating intestinal tuberculosis from Crohn's disease: a systematic review with meta-analysis.

PubMed

Kedia, Saurabh; Sharma, Raju; Sreenivas, Vishnubhatla; Madhusudhan, Kumble Seetharama; Sharma, Vishal; Bopanna, Sawan; Pratap Mouli, Venigalla; Dhingra, Rajan; Yadav, Dawesh Prakash; Makharia, Govind; Ahuja, Vineet

2017-04-01

Abdominal computed tomography (CT) can noninvasively image the entire gastrointestinal tract and assess extraintestinal features that are important in differentiating Crohn's disease (CD) and intestinal tuberculosis (ITB). The present meta-analysis pooled the results of all studies on the role of CT abdomen in differentiating between CD and ITB. We searched PubMed and Embase for all publications in English that analyzed the features differentiating between CD and ITB on abdominal CT. The features included comb sign, necrotic lymph nodes, asymmetric bowel wall thickening, skip lesions, fibrofatty proliferation, mural stratification, ileocaecal area, long segment, and left colonic involvements. Sensitivity, specificity, positive and negative likelihood ratios, and diagnostic odds ratio (DOR) were calculated for all the features. Symmetric receiver operating characteristic curve was plotted for features present in >3 studies. Heterogeneity and publication bias was assessed and sensitivity analysis was performed by excluding studies that compared features on conventional abdominal CT instead of CT enterography (CTE). We included 6 studies (4 CTE, 1 conventional abdominal CT, and 1 CTE+conventional abdominal CT) involving 417 and 195 patients with CD and ITB, respectively. Necrotic lymph nodes had the highest diagnostic accuracy (sensitivity, 23%; specificity, 100%; DOR, 30.2) for ITB diagnosis, and comb sign (sensitivity, 82%; specificity, 81%; DOR, 21.5) followed by skip lesions (sensitivity, 86%; specificity, 74%; DOR, 16.5) had the highest diagnostic accuracy for CD diagnosis. On sensitivity analysis, the diagnostic accuracy of other features excluding asymmetric bowel wall thickening remained similar. Necrotic lymph nodes and comb sign on abdominal CT had the best diagnostic accuracy in differentiating CD and ITB.

Language evaluation protocol for children aged 2 months to 23 months: analysis of sensitivity and specificity.

PubMed

Labanca, Ludimila; Alves, Cláudia Regina Lindgren; Bragança, Lidia Lourenço Cunha; Dorim, Diego Dias Ramos; Alvim, Cristina Gonçalves; Lemos, Stela Maris Aguiar

2015-01-01

To establish cutoff points for the analysis of the Behavior Observation Form (BOF) of children in the ages of 2 to 23 months and evaluate the sensitivity and specificity by age group and domains (Emission, Reception, and Cognitive Aspects of Language). The sample consisted of 752 children who underwent BOF. Each child was classified as having appropriate language development for the age or having possible risk of language impairment. Performance Indicators (PI) were calculated in each domain as well as the overall PI in all domains. The values for sensitivity and specificity were also calculated. The cutoff points for possible risk of language impairment for each domain and each age group were obtained using the receiver operating characteristics curve. The results of the study revealed that one-third of the assessed children have a risk of language impairment in the first two years of life. The analysis of BOF showed high sensitivity (>90%) in all categories and in all age groups; however, the chance of false-positive results was higher than 20% in the majority of aspects evaluated. It was possible to establish the cutoff points for all categories and age groups with good correlation between sensitivity and specificity, except for the age group of 2 to 6 months. This study provides important contributions to the discussion on the evaluation of the language development of children younger than 2 years.

The sensitivity and specificity of thermometry and plethysmography in the assessment of hand-arm vibration syndrome.

PubMed

Thompson, Aaron; House, Ron; Manno, Michael

2008-05-01

Finger plethysmography and thermometry are objective measures used to assess the vascular aspect of hand-arm vibration syndrome (HAVS). Research to date shows poor correlation between these tests and Stockholm Workshop Scale (SWS) vascular stage. Clinicians, researchers and compensation boards require objective means to diagnose and quantify HAVS. To define the specificity and sensitivity of thermometry and plethysmography using the SWS as the reference criterion. A secondary goal was to consider cut points for the tests optimizing sensitivity and specificity. A cross-sectional analysis was conducted on HAVS patients seen at an occupational medicine specialty clinic. Plethysmography and thermometry were analyzed using SWS vascular stage as the outcome variable. Logistic regression controlled for age, smoking and time since last vibration exposure and use of vasoactive medications. The sensitivity and specificity of the combined tests were calculated using varying cut points. A total of 139 patients consented to participate in the study. Plethysmography stage 1 or greater showed the highest sensitivity (sensitivity 94% and specificity 15%). Specificity was optimized combining plethysmography stage 3 and thermometry stage 3 (specificity 98% and sensitivity 23%). Maximal diagnostic accuracy was achieved by plethysmography alone setting the criteria for a positive test as being stage 1 or greater (70%). Neither plethysmography nor thermometry either alone or in combination demonstrated sufficient sensitivity and specificity to serve as an objective correlate for SWS vascular stage. All combinations of plethysmography and thermometry showed a lower specificity than sensitivity indicating that the SWS may be less sensitive in detecting vascular pathology than the objective tests.

BAYESIAN ANALYSIS TO EVALUATE TESTS FOR THE DETECTION OF MYCOBACTERIUM BOVIS INFECTION IN FREE-RANGING WILD BISON (BISON BISON ATHABASCAE) IN THE ABSENCE OF A GOLD STANDARD.

PubMed

Chapinal, Núria; Schumaker, Brant A; Joly, Damien O; Elkin, Brett T; Stephen, Craig

2015-07-01

We estimated the sensitivity and specificity of the caudal-fold skin test (CFT), the fluorescent polarization assay (FPA), and the rapid lateral-flow test (RT) for the detection of Mycobacterium bovis in free-ranging wild wood bison (Bison bison athabascae), in the absence of a gold standard, by using Bayesian analysis, and then used those estimates to forecast the performance of a pairwise combination of tests in parallel. In 1998-99, 212 wood bison from Wood Buffalo National Park (Canada) were tested for M. bovis infection using CFT and two serologic tests (FPA and RT). The sensitivity and specificity of each test were estimated using a three-test, one-population, Bayesian model allowing for conditional dependence between FPA and RT. The sensitivity and specificity of the combination of CFT and each serologic test in parallel were calculated assuming conditional independence. The test performance estimates were influenced by the prior values chosen. However, the rank of tests and combinations of tests based on those estimates remained constant. The CFT was the most sensitive test and the FPA was the least sensitive, whereas RT was the most specific test and CFT was the least specific. In conclusion, given the fact that gold standards for the detection of M. bovis are imperfect and difficult to obtain in the field, Bayesian analysis holds promise as a tool to rank tests and combinations of tests based on their performance. Combining a skin test with an animal-side serologic test, such as RT, increases sensitivity in the detection of M. bovis and is a good approach to enhance disease eradication or control in wild bison.

Evaluation of Visual Field Progression in Glaucoma: Quasar Regression Program and Event Analysis.

PubMed

Díaz-Alemán, Valentín T; González-Hernández, Marta; Perera-Sanz, Daniel; Armas-Domínguez, Karintia

2016-01-01

To determine the sensitivity, specificity and agreement between the Quasar program, glaucoma progression analysis (GPA II) event analysis and expert opinion in the detection of glaucomatous progression. The Quasar program is based on linear regression analysis of both mean defect (MD) and pattern standard deviation (PSD). Each series of visual fields was evaluated by three methods; Quasar, GPA II and four experts. The sensitivity, specificity and agreement (kappa) for each method was calculated, using expert opinion as the reference standard. The study included 439 SITA Standard visual fields of 56 eyes of 42 patients, with a mean of 7.8 ± 0.8 visual fields per eye. When suspected cases of progression were considered stable, sensitivity and specificity of Quasar, GPA II and the experts were 86.6% and 70.7%, 26.6% and 95.1%, and 86.6% and 92.6% respectively. When suspected cases of progression were considered as progressing, sensitivity and specificity of Quasar, GPA II and the experts were 79.1% and 81.2%, 45.8% and 90.6%, and 85.4% and 90.6% respectively. The agreement between Quasar and GPA II when suspected cases were considered stable or progressing was 0.03 and 0.28 respectively. The degree of agreement between Quasar and the experts when suspected cases were considered stable or progressing was 0.472 and 0.507. The degree of agreement between GPA II and the experts when suspected cases were considered stable or progressing was 0.262 and 0.342. The combination of MD and PSD regression analysis in the Quasar program showed better agreement with the experts and higher sensitivity than GPA II.

Cyst fluid analysis in the differential diagnosis of pancreatic cystic lesions: a pooled analysis.

PubMed

van der Waaij, Laurens A; van Dullemen, Hendrik M; Porte, Robert J

2005-09-01

Pancreatic cystic tumors commonly include serous cystadenoma (SCA), mucinous cystadenoma (MCA), and mucinous cystadenocarcinoma (MCAC). A differential diagnosis with pseudocysts (PC) can be difficult. Radiologic criteria are not reliable. The objective of the study is to investigate the value of cyst fluid analysis in the differential diagnosis of benign (SCA, PC) vs. premalignant or malignant (MCA, MCAC) lesions. A search in PubMed was performed with the search terms cyst, pancrea, and fluid. Articles about cyst fluid analysis of pancreatic lesions that contained the individual data of at least 7 patients were included in the study. Data of all individual patients were combined and were plotted in scatter grams. Cutoff levels were determined. Twelve studies were included, which comprised data of 450 patients. Cysts with an amylase concentration <250 U/L were SCA, MCA, or MCAC (sensitivity 44%, specificity 98%) and, thus, virtually excluded PC. A carcinoembryonic antigen (CEA) <5 ng/mL suggested a SCA or PC (sensitivity 50%, specificity 95%). A CEA >800 ng/mL strongly suggested MCA or MCAC (sensitivity 48%, specificity 98%). A carbohydrate-associated antigen (CA) 19-9 <37 U/mL strongly suggested PC or SCA (sensitivity 19%, specificity 98%). Cytologic examination revealed malignant cells in 48% of MCAC (n = 111). Most pancreatic cystic tumors should be resected without the need for cyst fluid analysis. However, in asymptomatic patients, in patients with an increased surgical risk, and, in patients in whom there is a diagnostic uncertainty about the presence of a PC, cyst fluid analysis helps to determine the optimal therapeutic strategy.

Connectome sensitivity or specificity: which is more important?

PubMed

Zalesky, Andrew; Fornito, Alex; Cocchi, Luca; Gollo, Leonardo L; van den Heuvel, Martijn P; Breakspear, Michael

2016-11-15

Connectomes with high sensitivity and high specificity are unattainable with current axonal fiber reconstruction methods, particularly at the macro-scale afforded by magnetic resonance imaging. Tensor-guided deterministic tractography yields sparse connectomes that are incomplete and contain false negatives (FNs), whereas probabilistic methods steered by crossing-fiber models yield dense connectomes, often with low specificity due to false positives (FPs). Densely reconstructed probabilistic connectomes are typically thresholded to improve specificity at the cost of a reduction in sensitivity. What is the optimal tradeoff between connectome sensitivity and specificity? We show empirically and theoretically that specificity is paramount. Our evaluations of the impact of FPs and FNs on empirical connectomes indicate that specificity is at least twice as important as sensitivity when estimating key properties of brain networks, including topological measures of network clustering, network efficiency and network modularity. Our asymptotic analysis of small-world networks with idealized modular structure reveals that as the number of nodes grows, specificity becomes exactly twice as important as sensitivity to the estimation of the clustering coefficient. For the estimation of network efficiency, the relative importance of specificity grows linearly with the number of nodes. The greater importance of specificity is due to FPs occurring more prevalently between network modules rather than within them. These spurious inter-modular connections have a dramatic impact on network topology. We argue that efforts to maximize the sensitivity of connectome reconstruction should be realigned with the need to map brain networks with high specificity. Copyright © 2016 Elsevier Inc. All rights reserved.

Allergenicity and cross-reactivity of booklice (Liposcelis bostrichophila): a common household insect pest in Japan.

PubMed

Fukutomi, Yuma; Kawakami, Yuji; Taniguchi, Masami; Saito, Akemi; Fukuda, Azumi; Yasueda, Hiroshi; Nakazawa, Takuya; Hasegawa, Maki; Nakamura, Hiroyuki; Akiyama, Kazuo

2012-01-01

Booklice (Liposcelis bostrichophila) are a common household insect pest distributed worldwide. Particularly in Japan, they infest 'tatami' mats and are the most frequently detected insect among all detectable insects, present at a frequency of about 90% in dust samples. Although it has been hypothesized that they are an important indoor allergen, studies on their allergenicity have been limited. To clarify the allergenicity of booklice and the cross-reactivity of this insect allergen with allergens of other insects, patients sensitized to booklice were identified from 185 Japanese adults with allergic asthma using skin tests and IgE-ELISA. IgE-inhibition analysis, immunoblotting and immunoblotting-inhibition analysis were performed using sera from these patients. Allergenic proteins contributing to specific sensitization to booklice were identified by two-dimensional electrophoresis and two-dimensional immunoblotting. The booklouse-specific IgE antibody was detected in sera from 41 patients (22% of studied patients). IgE inhibition analysis revealed that IgE reactivity to the booklouse allergen in the sera from one third of booklouse-sensitized patients was not inhibited by preincubation with extracts from any other environmental insects in this study. Immunoblotting identified a 26-kD protein from booklouse extract as the allergenic protein contributing to specific sensitization to booklice. The amino acid sequence of peptide fragments of this protein showed no homology to those of previously described allergenic proteins, indicating that this protein is a new allergen. Sensitization to booklice was relatively common and specific sensitization to this insect not related to insect panallergy was indicated in this population. Copyright © 2011 S. Karger AG, Basel.

Review-of-systems questionnaire as a predictive tool for psychogenic nonepileptic seizures.

PubMed

Robles, Liliana; Chiang, Sharon; Haneef, Zulfi

2015-04-01

Patients with refractory epilepsy undergo video-electroencephalography for seizure characterization, among whom approximately 10-30% will be discharged with the diagnosis of psychogenic nonepileptic seizures (PNESs). Clinical PNES predictors have been described but in general are not sensitive or specific. We evaluated whether multiple complaints in a routine review-of-system (ROS) questionnaire could serve as a sensitive and specific marker of PNESs. We performed a retrospective analysis of a standardized ROS questionnaire completed by patients with definite PNESs and epileptic seizures (ESs) diagnosed in our adult epilepsy monitoring unit. A multivariate analysis of covariance (MANCOVA) was used to determine whether groups with PNES and ES differed with respect to the percentage of complaints in the ROS questionnaire. Tenfold cross-validation was used to evaluate the predictive error of a logistic regression classifier for PNES status based on the percentage of positive complaints in the ROS questionnaire. A total of 44 patients were included for analysis. Patients with PNESs had a significantly higher number of complaints in the ROS questionnaire compared to patients with epilepsy. A threshold of 17% positive complaints achieved a 78% specificity and 85% sensitivity for discriminating between PNESs and ESs. We conclude that the routine ROS questionnaire may be a sensitive and specific predictive tool for discriminating between PNESs and ESs. Published by Elsevier Inc.

Comparison of Heidelberg Retina Tomograph-3 glaucoma probability score and Moorfields regression analysis of optic nerve head in glaucoma patients and healthy individuals.

PubMed

Caglar, Çagatay; Gul, Adem; Batur, Muhammed; Yasar, Tekin

2017-01-01

To compare the sensitivity and specificity of Moorfields regression analysis (MRA) and glaucoma probability score (GPS) between healthy and glaucomatous eyes with Heidelberg Retinal Tomograph 3 (HRT-3). The study included 120 eyes of 75 glaucoma patients and 138 eyes of 73 normal subjects, for a total of 258 eyes of 148 individuals. All measurements were performed with the HRT-3. Diagnostic test criteria (sensitivity, specificity, etc.) were used to evaluate how efficiently GPS and MRA algorithms in the HRT-3 discriminated between the glaucoma and control groups. The GPS showed 88 % sensitivity and 66 % specificity, whereas MRA had 71.5 % sensitivity and 82.5 % specificity. There was 71 % agreement between the final results of MRA and GPS in the glaucoma group. Excluding borderline patients from both analyses resulted in 91.6 % agreement. In the control group the level of agreement between MRA and GPS was 64 % including borderline patients and 84.1 % after excluding borderline patients. The accuracy rate is 92 % for MRA and 91 % for GPS in the glaucoma group excluding borderline patients. The difference was nor statistically different. In both cases, agreement was higher between MRA and GPS in the glaucoma group. We found that both sensitivity and specificity increased with disc size for MRA, while the sensitivity increased and specificity decreased with larger disc sizes for GPS. HRT is able to quantify and clearly reveal structural changes in the ONH and RNFL in glaucoma.

How sensitive and specific is urinalysis 'dipstick' testing for detection of hyperglycaemia and ketosis? An audit of findings from coronial autopsies.

PubMed

Mitchell, Rebecca; Thomas, Sunethra Devika; Langlois, Neil E I

2013-10-01

Biochemical analysis of glucose and ketones in the vitreous humour obtained at post-mortem examination is representative of the levels in the blood prior to death. Elevated levels can be indicative of conditions including diabetic ketoacidosis, which can be a cause for unexpected death. A rapid screening test for such conditions can be performed during the autopsy through urinalysis using test strips (urine 'dipstick' testing). The aim of this study was to assess the utility of urinalysis testing for post-mortem detection of derangements of glucose and ketone levels. The results of vitreous biochemical analysis and urinalysis were collated from 188 forensic autopsy cases. A vitreous glucose result of above 10 mmol/L was regarded as high. When this was compared to urinalysis results it was found that any urinalysis result above negative had a sensitivity of 0.83 and a specificity of 0.93. A vitreous ketone level of above 5 mmol/L was regarded as significantly elevated; a urinalysis result above negative had a sensitivity of 1, but a specificity of 0.12. Urinalysis ('dipstick' testing) for glucose has a good sensitivity and specificity for high vitreous glucose levels, which are regarded as indicative of pathological hyperglycaemia during life. It was found that urine testing for ketones either has an excellent sensitivity with low specificity or a poor sensitivity with a good specificity; however, this finding has to be viewed in the context of uncertainty of the biochemical level of significant ketosis.

[The role of endotracheal aspirate culture in the diagnosis of ventilator-associated pneumonia: a meta analysis].

PubMed

Wang, Fei; He, Bei

2013-01-01

To investigate the role of endotracheal aspirate (EA) culture in the diagnosis and antibiotic management in ventilator-associated pneumonia (VAP). We searched CNKI, Wanfang, PUBMED and EMBASE databases published from January 1990 to December 2011, to find relevant literatures on VAP microbiological diagnostic techniques including EA and bronchoalveolar lavage (BALF). The following key words were used: ventilator associated pneumonia, diagnosis and adult. Meta-analysis was performed and the sensitivity and specificity of EA on VAP diagnosis were calculated. Our literature search identified 1665 potential articles, 8 of which fulfilled our selection criteria including 561 patients with paired cultures. Using BALF quantitative culture as reference standard, the sensitivity and specificity of EA were 72% and 71%. When considering quantitative culture of EA only, the sensitivity and specificity improved to 90% and 65%, while the positive and the negative predictive values were 68% and 89% respectively. However, the sensitivity and specificity of semi-quantitative culture of EA were only 50% and 80%, with a positive predictive value of 77% and a negative predictive value of 58% respectively. EA culture had relatively poor sensitivity and specificity, although quantitative culture of EA only could improve the sensitivity. Initiating therapy on the basis of EA quantitative culture may still result in excessive antibiotic usage. Our data suggested that EA could provide some information for clinical decision but could not replace the role of BALF quantitative culture in VAP diagnosis.

Receiver operating characteristic analysis of prediction for gastric cancer development using serum pepsinogen and Helicobacter pylori antibody tests.

PubMed

Hamashima, Chisato; Sasazuki, Shizuka; Inoue, Manami; Tsugane, Shoichiro

2017-03-09

Chronic Helicobacter pylori infection plays a central role in the development of gastric cancer as shown by biological and epidemiological studies. The H. pylori antibody and serum pepsinogen (PG) tests have been anticipated to predict gastric cancer development. We determined the predictive sensitivity and specificity of gastric cancer development using these tests. Receiver operating characteristic analysis was performed, and areas under the curve were estimated. The predictive sensitivity and specificity of gastric cancer development were compared among single tests and combined methods using serum pepsinogen and H. pylori antibody tests. From a large-scale population-based cohort of over 100,000 subjects followed between 1990 and 2004, 497 gastric cancer subjects and 497 matched healthy controls were chosen. The predictive sensitivity and specificity were low in all single tests and combination methods. The highest predictive sensitivity and specificity were obtained for the serum PG I/II ratio. The optimal PG I/II cut-off values were 2.5 and 3.0. At a PG I/II cut-off value of 3.0, the sensitivity was 86.9% and the specificity was 39.8%. Even if three biomarkers were combined, the sensitivity was 97.2% and the specificity was 21.1% when the cut-off values were 3.0 for PG I/II, 70 ng/mL for PG I, and 10.0 U/mL for H. pylori antibody. The predictive accuracy of gastric cancer development was low with the serum pepsinogen and H. pylori antibody tests even if these tests were combined. To adopt these biomarkers for gastric cancer screening, a high specificity is required. When these tests are adopted for gastric cancer screening, they should be carefully interpreted with a clear understanding of their limitations.

Global Sensitivity and Data-Worth Analyses in iTOUGH2: User's Guide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wainwright, Haruko Murakami; Finsterle, Stefan

2016-07-15

This manual explains the use of local sensitivity analysis, the global Morris OAT and Sobol’ methods, and a related data-worth analysis as implemented in iTOUGH2. In addition to input specification and output formats, it includes some examples to show how to interpret results.

Cost effectiveness analysis of screening for sight threatening diabetic eye disease

PubMed Central

James, Marilyn; Turner, David A; Broadbent, Deborah M; Vora, Jiten; Harding, Simon P

2000-01-01

Objective To measure the cost effectiveness of systematic photographic screening for sight threatening diabetic eye disease compared with existing practice. Design Cost effectiveness analysis Setting Liverpool. Subjects A target population of 5000 diabetic patients invited for screening. Main outcome measures Cost effectiveness (cost per true positive) of systematic and opportunistic programmes; incremental cost effectiveness of replacing opportunistic with systematic screening. Results Baseline prevalence of sight threatening eye disease was 14.1%. The cost effectiveness of the systematic programme was £209 (sensitivity 89%, specificity 86%, compliance 80%, annual cost £104 996) and of the opportunistic programme was £289 (combined sensitivity 63%, specificity 92%, compliance 78%, annual cost £99 981). The incremental cost effectiveness of completely replacing the opportunistic programme was £32. Absolute values of cost effectiveness were highly sensitive to varying prevalence, sensitivity and specificity, compliance, and programme size. Conclusion Replacing existing programmes with systematic screening for diabetic eye disease is justified. PMID:10856062

Optical Coherence Tomography Angiography versus Dye Angiography in Age-Related Macular Degeneration: Sensitivity and Specificity Analysis.

PubMed

Nikolopoulou, Eleni; Lorusso, Massimo; Micelli Ferrari, Luisa; Cicinelli, Maria Vittoria; Bandello, Francesco; Querques, Giuseppe; Micelli Ferrari, Tommaso

2018-01-01

Optical coherence tomography angiography (OCTA) could be a valid tool to detect choroidal neovascularization (CNV) in neovascular age-related macular degeneration (nAMD), allowing the analysis of the type, the morphology, and the extension of CNV in most of the cases. To determine the sensitivity and specificity of OCTA in detecting CNV secondary to nAMD, compared to fluorescein angiography (FA) and indocyanine green angiography (ICGA). Prospective observational study. Patients with suspected nAMD were recruited between May and December 2016. Patients underwent FA, ICGA, spectral domain OCT, and OCTA (AngioVue, Optovue, Inc.). Sensitivity and specificity of FA, with or without ICGA, were assessed and compared with OCTA. Seventy eyes of 70 consecutive patients were included: 32 eyes (45.7%) with type I CNV, 8 eyes (11.4%) with type II CNV, 4 eyes (5.7%) with type III CNV, 6 eyes (8.6%) with mixed type I and type II CNV, and 20 eyes (28.6%) with no CNV. Sensitivity of OCTA was 88% and specificity was 90%. Concordance between FA/ICGA and OCTA was very good (0,91; range 0,81-1,00). OCTA showed high sensitivity and specificity for detection of CNV. Concordance between OCTA and gold-standard dye-based techniques was excellent. OCTA may represent a first-line noninvasive method for the diagnosis of nAMD.

A closure test for time-specific capture-recapture data

USGS Publications Warehouse

Stanley, T.R.; Burnham, K.P.

1999-01-01

The assumption of demographic closure in the analysis of capture-recapture data under closed-population models is of fundamental importance. Yet, little progress has been made in the development of omnibus tests of the closure assumption. We present a closure test for time-specific data that, in principle, tests the null hypothesis of closed-population model M(t) against the open-population Jolly-Seber model as a specific alternative. This test is chi-square, and can be decomposed into informative components that can be interpreted to determine the nature of closure violations. The test is most sensitive to permanent emigration and least sensitive to temporary emigration, and is of intermediate sensitivity to permanent or temporary immigration. This test is a versatile tool for testing the assumption of demographic closure in the analysis of capture-recapture data.

Diagnostic Performance of DNA Hypermethylation Markers in Peripheral Blood for the Detection of Colorectal Cancer: A Meta-Analysis and Systematic Review

PubMed Central

Li, Bingsheng; Gan, Aihua; Chen, Xiaolong; Wang, Xinying; He, Weifeng; Zhang, Xiaohui; Huang, Renxiang; Zhou, Shuzhu; Song, Xiaoxiao; Xu, Angao

2016-01-01

DNA hypermethylation in blood is becoming an attractive candidate marker for colorectal cancer (CRC) detection. To assess the diagnostic accuracy of blood hypermethylation markers for CRC in different clinical settings, we conducted a meta-analysis of published reports. Of 485 publications obtained in the initial literature search, 39 studies were included in the meta-analysis. Hypermethylation markers in peripheral blood showed a high degree of accuracy for the detection of CRC. The summary sensitivity was 0.62 [95% confidence interval (CI), 0.56–0.67] and specificity was 0.91 (95% CI, 0.89–0.93). Subgroup analysis showed significantly greater sensitivity for the methylated Septin 9 gene (SEPT9) subgroup (0.75; 95% CI, 0.67–0.81) than for the non-methylated SEPT9 subgroup (0.58; 95% CI, 0.52–0.64). Sensitivity and specificity were not affected significantly by target gene number, CRC staging, study region, or methylation analysis method. These findings show that hypermethylation markers in blood are highly sensitive and specific for CRC detection, with methylated SEPT9 being particularly robust. The diagnostic performance of hypermethylation markers, which have varied across different studies, can be improved by marker optimization. Future research should examine variation in diagnostic accuracy according to non-neoplastic factors. PMID:27158984

Performance of the 2015 American College of Rheumatology/European League Against Rheumatism gout classification criteria in Thai patients.

PubMed

Louthrenoo, Worawit; Jatuworapruk, Kanon; Lhakum, Panomkorn; Pattamapaspong, Nuttaya

2017-05-01

To evaluate the sensitivity and specificity of the 2015 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) gout classification criteria in Thai patients presenting with acute arthritis in a real-life setting. Data were analyzed on consecutive patients presenting with arthritis of less than 2 weeks duration. Sensitivity and specificity were calculated by using the presence of monosodium urate (MSU) crystals in the synovial fluid or tissue aspirate as gold standard for gout diagnosis. Subgroup analysis was performed in patients with early disease (≤2 years), established disease (>2 years), and those without tophus. Additional analysis also was performed in non-tophaceous gout patients, and patients with acute calcium pyrophosphate dihydrate crystal arthritis were used as controls. One hundred and nine gout and 74 non-gout patients participated in this study. Full ACR/EULAR classification criteria had sensitivity and specificity of 90.2 and 90.0%, respectively; and 90.2 and 85.0%, respectively, when synovial fluid microscopy was excluded. Clinical-only criteria yielded sensitivity and specificity of 79.8 and 87.8%, respectively. The criteria performed well among patients with early and non-tophaceous disease, but had lower specificity in patients with established disease. The variation of serum uric acid level was a major limitation of the classification criteria. The ACR/EULAR classification criteria had high sensitivity and specificity in Thai patients presenting with acute arthritis, even when clinical criteria alone were used.

[Comparison of simple pooling and bivariate model used in meta-analyses of diagnostic test accuracy published in Chinese journals].

PubMed

Huang, Yuan-sheng; Yang, Zhi-rong; Zhan, Si-yan

2015-06-18

To investigate the use of simple pooling and bivariate model in meta-analyses of diagnostic test accuracy (DTA) published in Chinese journals (January to November, 2014), compare the differences of results from these two models, and explore the impact of between-study variability of sensitivity and specificity on the differences. DTA meta-analyses were searched through Chinese Biomedical Literature Database (January to November, 2014). Details in models and data for fourfold table were extracted. Descriptive analysis was conducted to investigate the prevalence of the use of simple pooling method and bivariate model in the included literature. Data were re-analyzed with the two models respectively. Differences in the results were examined by Wilcoxon signed rank test. How the results differences were affected by between-study variability of sensitivity and specificity, expressed by I2, was explored. The 55 systematic reviews, containing 58 DTA meta-analyses, were included and 25 DTA meta-analyses were eligible for re-analysis. Simple pooling was used in 50 (90.9%) systematic reviews and bivariate model in 1 (1.8%). The remaining 4 (7.3%) articles used other models pooling sensitivity and specificity or pooled neither of them. Of the reviews simply pooling sensitivity and specificity, 41(82.0%) were at the risk of wrongly using Meta-disc software. The differences in medians of sensitivity and specificity between two models were both 0.011 (P<0.001, P=0.031 respectively). Greater differences could be found as I2 of sensitivity or specificity became larger, especially when I2>75%. Most DTA meta-analyses published in Chinese journals(January to November, 2014) combine the sensitivity and specificity by simple pooling. Meta-disc software can pool the sensitivity and specificity only through fixed-effect model, but a high proportion of authors think it can implement random-effect model. Simple pooling tends to underestimate the results compared with bivariate model. The greater the between-study variance is, the more likely the simple pooling has larger deviation. It is necessary to increase the knowledge level of statistical methods and software for meta-analyses of DTA data.

Diagnostic value of stool DNA testing for multiple markers of colorectal cancer and advanced adenoma: a meta-analysis.

PubMed

Yang, Hua; Xia, Bing-Qing; Jiang, Bo; Wang, Guozhen; Yang, Yi-Peng; Chen, Hao; Li, Bing-Sheng; Xu, An-Gao; Huang, Yun-Bo; Wang, Xin-Ying

2013-08-01

The diagnostic value of stool DNA (sDNA) testing for colorectal neoplasms remains controversial. To compensate for the lack of large-scale unbiased population studies, a meta-analysis was performed to evaluate the diagnostic value of sDNA testing for multiple markers of colorectal cancer (CRC) and advanced adenoma. The PubMed, Science Direct, Biosis Review, Cochrane Library and Embase databases were systematically searched in January 2012 without time restriction. Meta-analysis was performed using a random-effects model using sensitivity, specificity, diagnostic OR (DOR), summary ROC curves, area under the curve (AUC), and 95% CIs as effect measures. Heterogeneity was measured using the χ(2) test and Q statistic; subgroup analysis was also conducted. A total of 20 studies comprising 5876 individuals were eligible. There was no heterogeneity for CRC, but adenoma and advanced adenoma harboured considerable heterogeneity influenced by risk classification and various detection markers. Stratification analysis according to risk classification showed that multiple markers had a high DOR for the high-risk subgroups of both CRC (sensitivity 0.759 [95% CI 0.711 to 0.804]; specificity 0.883 [95% CI 0.846 to 0.913]; AUC 0.906) and advanced adenoma (sensitivity 0.683 [95% CI 0.584 to 0.771]; specificity 0.918 [95% CI 0.866 to 0.954]; AUC 0.946) but not for the average-risk subgroups of either. In the methylation subgroup, sDNA testing had significantly higher DOR for CRC (sensitivity 0.753 [95% CI 0.685 to 0.812]; specificity 0.913 [95% CI 0.860 to 0.950]; AUC 0.918) and advanced adenoma (sensitivity 0.623 [95% CI 0.527 to 0.712]; specificity 0.926 [95% CI 0.882 to 0.958]; AUC 0.910) compared with the mutation subgroup. There was no significant heterogeneity among studies for subgroup analysis. sDNA testing for multiple markers had strong diagnostic significance for CRC and advanced adenoma in high-risk subjects. Methylation makers had more diagnostic value than mutation markers.

Performance of the 2012 Systemic Lupus International Collaborating Clinics classification criteria versus the 1997 American College of Rheumatology classification criteria in adult and juvenile systemic lupus erythematosus. A systematic review and meta-analysis.

PubMed

Hartman, Esther A R; van Royen-Kerkhof, Annet; Jacobs, Johannes W G; Welsing, Paco M J; Fritsch-Stork, Ruth D E

2018-03-01

To evaluate the performance in classifying systemic lupus erythematosus by the 2012 Systemic Lupus International Collaborating Clinics criteria (SLICC'12), versus the revised American College of Rheumatology criteria from 1997 (ACR'97) in adult and juvenile SLE patients. A systematic literature search was conducted in PubMed and Embase for studies comparing SLICC'12 and ACR'97 with clinical diagnosis. A meta-analysis was performed to estimate the sensitivity and specificity of SLICC'12 and ACR'97. To assess classification earlier in the disease by either set, sensitivity and specificity were compared for patients with disease duration <5years. Sensitivity and specificity of individual criteria items were also assessed. In adult SLE (nine studies: 5236 patients, 1313 controls), SLICC'12 has higher sensitivity (94.6% vs. 89.6%) and similar specificity (95.5% vs. 98.1%) compared to ACR'97. For juvenile SLE (four studies: 568 patients, 339 controls), SLICC'12 demonstrates higher sensitivity (99.9% vs. 84.3%) than ACR'97, but much lower specificity (82.0% vs. 94.1%). SLICC'12 classifies juvenile SLE patients earlier in disease course. Individual items contributing to diagnostic accuracy are low complement, anti-ds DNA and acute cutaneous lupus in SLICC'12, and the immunologic and hematologic disorder in ACR'97. Based on sensitivity and specificity SLICC'12 is best for adult SLE. Following the view that higher specificity, i.e. avoidance of false positives, is preferable, ACR'97 is best for juvenile SLE even if associated with lower sensitivity. Our results on the contribution of the individual items of SLICC'12 and ACR´97 may be of value in future efforts to update classification criteria. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

[Meta-analysis of diagnostic capability of frequency-doubling technology (FDT) for primary glaucoma].

PubMed

Liu, Ting; He, Xiang-ge

2006-05-01

To evaluate the overall diagnostic capabilities of frequency-doubling technology (FDT) in patients of primary glaucoma, with standard automated perimetry (SAP) and/or optic disc appearance as the gold standard. A comprehensive electric search in MEDLINE, EMBASE, Cochrane Library, BIOSIS, Previews, HMIC, IPA, OVID, CNKI, CBMdisc, VIP information, CMCC, CCPD, SSreader and 21dmedia and a manual search in related textbooks, journals, congress articles and their references were performed to identify relevant English and Chinese language articles. Criteria for adaptability were established according to validity criteria for diagnostic research published by the Cochrane Methods Group on Screening and Diagnostic Tests. Quality of the included articles was assessed and relevant materials were extracted for studying. Statistical analysis was performed with Meta Test version 0.6 software. Heterogeneity of the included articles was tested, which was used to select appropriate effect model to calculate pooled weighted sensitivity and specificity. Summary Receiver Operating Characteristic (SROC) curve was established and the area under the curve (AUC) was calculated. Finally, sensitivity analysis was performed. Fifteen English articles (21 studies) of 206 retrieved articles were included in the present study, with a total of 3172 patients. The reported sensitivity of FDT ranged from 0.51 to 1.00, and specificity from 0.58 to 1.00. The pooled weighted sensitivity and specificity for FDT with 95% confidence intervals (95% CI) after correction for standard error were 0.86 (0.80 - 0.90), 0.87 (0.81 - 0.91), respectively. The AUC of SROC was 93.01%. Sensitivity analysis demonstrated no disproportionate influences of individual study. The included articles are of good quality and FDT can be a highly efficient diagnostic test for primary glaucoma based on Meta-analysis. However, a high quality perspective study is still required for further analysis.

Phase 1 of the near term hybrid passenger vehicle development program. Appendix D: Sensitivity analysis

NASA Technical Reports Server (NTRS)

Traversi, M.

1979-01-01

Data are presented on the sensitivity of: (1) mission analysis results to the boundary values given for number of passenger cars and average annual vehicle miles traveled per car; (2) vehicle characteristics and performance to specifications; and (3) tradeoff study results to the expected parameters.

Accuracy of screening women at familial risk of breast cancer without a known gene mutation: Individual patient data meta-analysis.

PubMed

Phi, Xuan-Anh; Houssami, Nehmat; Hooning, Maartje J; Riedl, Christopher C; Leach, Martin O; Sardanelli, Francesco; Warner, Ellen; Trop, Isabelle; Saadatmand, Sepideh; Tilanus-Linthorst, Madeleine M A; Helbich, Thomas H; van den Heuvel, Edwin R; de Koning, Harry J; Obdeijn, Inge-Marie; de Bock, Geertruida H

2017-11-01

Women with a strong family history of breast cancer (BC) and without a known gene mutation have an increased risk of developing BC. We aimed to investigate the accuracy of screening using annual mammography with or without magnetic resonance imaging (MRI) for these women outside the general population screening program. An individual patient data (IPD) meta-analysis was conducted using IPD from six prospective screening trials that had included women at increased risk for BC: only women with a strong familial risk for BC and without a known gene mutation were included in this analysis. A generalised linear mixed model was applied to estimate and compare screening accuracy (sensitivity, specificity and predictive values) for annual mammography with or without MRI. There were 2226 women (median age: 41 years, interquartile range 35-47) with 7478 woman-years of follow-up, with a BC rate of 12 (95% confidence interval 9.3-14) in 1000 woman-years. Mammography screening had a sensitivity of 55% (standard error of mean [SE] 7.0) and a specificity of 94% (SE 1.3). Screening with MRI alone had a sensitivity of 89% (SE 4.6) and a specificity of 83% (SE 2.8). Adding MRI to mammography increased sensitivity to 98% (SE 1.8, P < 0.01 compared to mammography alone) but lowered specificity to 79% (SE 2.7, P < 0.01 compared with mammography alone). In this population of women with strong familial BC risk but without a known gene mutation, in whom BC incidence was high both before and after age 50, adding MRI to mammography substantially increased screening sensitivity but also decreased its specificity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Preoperative identification of a suspicious adnexal mass: a systematic review and meta-analysis.

PubMed

Dodge, Jason E; Covens, Allan L; Lacchetti, Christina; Elit, Laurie M; Le, Tien; Devries-Aboud, Michaela; Fung-Kee-Fung, Michael

2012-07-01

To systematically review the existing literature in order to determine the optimal strategy for preoperative identification of the adnexal mass suspicious for ovarian cancer. A review of all systematic reviews and guidelines published between 1999 and 2009 was conducted as a first step. After the identification of a 2004 AHRQ systematic review on the topic, searches of MEDLINE for studies published since 2004 was also conducted to update and supplement the evidentiary base. A bivariate, random-effects meta-regression model was used to produce summary estimates of sensitivity and specificity and to plot summary ROC curves with 95% confidence regions. Four meta-analyses and 53 primary studies were included in this review. The diagnostic performance of each technology was compared and contrasted based on the summary data on sensitivity and specificity obtained from the meta-analysis. Results suggest that 3D ultrasonography has both a higher sensitivity and specificity when compared to 2D ultrasound. Established morphological scoring systems also performed with respectable sensitivity and specificity, each with equivalent diagnostic competence. Explicit scoring systems did not perform as well as other diagnostic testing methods. Assessment of an adnexal mass by colour Doppler technology was neither as sensitive nor as specific as simple ultrasonography. Of the three imaging modalities considered, MRI appeared to perform the best, although results were not statistically different from CT. PET did not perform as well as either MRI or CT. The measurement of the CA-125 tumour marker appears to be less reliable than do other available assessment methods. The best available evidence was collected and included in this rigorous systematic review and meta-analysis. The abundant evidentiary base provided the context and direction for the diagnosis of early-staged ovarian cancer. Copyright © 2012 Elsevier Inc. All rights reserved.

Diagnostic performance of matrix-assisted laser desorption ionisation time-of-flight mass spectrometry in blood bacterial infections: a systematic review and meta-analysis.

PubMed

Scott, Jamie S; Sterling, Sarah A; To, Harrison; Seals, Samantha R; Jones, Alan E

2016-07-01

Matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) has shown promise in decreasing time to identification of causative organisms compared to traditional methods; however, the utility of MALDI-TOF MS in a heterogeneous clinical setting is uncertain. To perform a systematic review on the operational performance of the Bruker MALDI-TOF MS system and evaluate published cut-off values compared to traditional blood cultures. A comprehensive literature search was performed. Studies were included if they performed direct MALDI-TOF MS analysis of blood culture specimens in human patients with suspected bacterial infections using the Bruker Biotyper software. Sensitivities and specificities of the combined studies were estimated using a hierarchical random effects linear model (REML) incorporating cut-off scores of ≥1.7 and ≥2.0. Fifty publications were identified, with 11 studies included after final review. The estimated sensitivity utilising a cut-off of ≥2.0 from the combined studies was 74.6% (95% CI = 67.9-89.3%), with an estimated specificity of 88.0% (95% CI = 74.8-94.7%). When assessing a cut-off of ≥1.7, the combined sensitivity increases to 92.8% (95% CI = 87.4-96.0%), but the estimated specificity decreased to 81.2% (95% CI = 61.9-96.6%). In this analysis, MALDI-TOF MS showed acceptable sensitivity and specificity in bacterial speciation with the current recommended cut-off point compared to blood cultures; however, lowering the cut-off point from ≥2.0 to ≥1.7 would increase the sensitivity of the test without significant detrimental effect on the specificity, which could improve clinician confidence in their results.

A receiver operated curve-based evaluation of change in sensitivity and specificity of cotinine urinalysis for detecting active tobacco use.

PubMed

Balhara, Yatan Pal Singh; Jain, Raka

2013-01-01

Tobacco use has been associated with various carcinomas including lung, esophagus, larynx, mouth, throat, kidney, bladder, pancreas, stomach, and cervix. Biomarkers such as concentration of cotinine in the blood, urine, or saliva have been used as objective measures to distinguish nonusers and users of tobacco products. A change in the cut-off value of urinary cotinine to detect active tobacco use is associated with a change in sensitivity and sensitivity of detection. The current study aimed at assessing the impact of using different cut-off thresholds of urinary cotinine on sensitivity and specificity of detection of smoking and smokeless tobacco product use among psychiatric patients. All the male subjects attending the psychiatry out-patient department of the tertiary care multispecialty teaching hospital constituted the sample frame for the current study in a cross-sectionally. Quantitative urinary cotinine assay was done by using ELISA kits of Calbiotech. Inc., USA. We used the receiver operating characteristic (ROC) curve to assess the sensitivity and specificity of various cut-off values of urinary cotinine to identify active smokers and users of smokeless tobacco products. ROC analysis of urinary cotinine levels in detection of self-reported smoking provided the area under curve (AUC) of 0.434. Similarly, the ROC analysis of urinary cotinine levels in detection of self-reported smoking revealed AUC of 0.44. The highest sensitivity and specificity of 100% for smoking were detected at the urinary cut-off value greater than or equal to 2.47 ng/ml. The choice of cut-off value of urinary cotinine used to distinguish nonusers form active users of tobacco products impacts the sensitivity as well as specificity of detection.

Diagnostic performance of body mass index to identify excess body fat in children with cerebral palsy.

PubMed

Duran, Ibrahim; Schulze, Josefa; Martakis, KyriakoS; Stark, Christina; Schoenau, Eckhard

2018-03-07

To assess the diagnostic performance of body mass index (BMI) cut-off values according to recommendations of the World Health Organization (WHO), the World Obesity Federation (WOF), and the German Society for Adiposity (DAG) to identify excess body fat in children with cerebral palsy (CP). The present study was a monocentric retrospective analysis of prospectively collected data among children and adolescents with CP participating in a rehabilitation programme. Excess body fat was defined as a body fat percentage above the 85th centile assessed by dual-energy X-ray absorptiometry. In total, 329 children (181 males, 148 females) with CP were eligible for analysis. The mean age was 12 years 4 months (standard deviation 2y 9mo). The BMI cut-off values for 'overweight' according to the WHO, WOF, and DAG showed the following sensitivities and specificities for the prediction of excess body fat in our population: WHO: sensitivity 0.768 (95% confidence interval [CI] 0.636-0.870), specificity 0.894 (95% CI 0.851-0.928); WOF: sensitivity 0.696 (95% CI 0.559-0.812), specificity 0.934 (95% CI 0.898-0.960); DAG: sensitivity 0.411 (95% CI 0.281-0.550), specificity 0.993 (95% CI 0.974-0.999). Body mass index showed high specificity, but low sensitivity in children with CP. Thus, 'normal-weight obese' children with CP were overlooked, when assessing excess body fat only using BMI. Excess body fat in children with cerebral palsy (CP) is less common than previously reported. Body mass index (BMI) had high specificity but low sensitivity in detecting excess body fat in children with CP. BMI evaluation criteria of the German Society for Adiposity could be improved in children with CP. © 2018 Mac Keith Press.

Single quantum dot analysis enables multiplexed point mutation detection by gap ligase chain reaction.

PubMed

Song, Yunke; Zhang, Yi; Wang, Tza-Huei

2013-04-08

Gene point mutations present important biomarkers for genetic diseases. However, existing point mutation detection methods suffer from low sensitivity, specificity, and a tedious assay processes. In this report, an assay technology is proposed which combines the outstanding specificity of gap ligase chain reaction (Gap-LCR), the high sensitivity of single-molecule coincidence detection, and the superior optical properties of quantum dots (QDs) for multiplexed detection of point mutations in genomic DNA. Mutant-specific ligation products are generated by Gap-LCR and subsequently captured by QDs to form DNA-QD nanocomplexes that are detected by single-molecule spectroscopy (SMS) through multi-color fluorescence burst coincidence analysis, allowing for multiplexed mutation detection in a separation-free format. The proposed assay is capable of detecting zeptomoles of KRAS codon 12 mutation variants with near 100% specificity. Its high sensitivity allows direct detection of KRAS mutation in crude genomic DNA without PCR pre-amplification. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Highly specific preoperative selection of solitary parathyroid adenoma cases in primary hyperparathyroidism by quantitative image analysis of the early-phase Technetium-99m sestamibi scan.

PubMed

Kim, DaeHee; Rhodes, Jeffrey A; Hashim, Jeffrey A; Rickabaugh, Lawrence; Brams, David M; Pinkus, Edward; Dou, Yamin

2018-06-07

Highly specific preoperative localizing test is required to select patients for minimally invasive parathyroidectomy (MIP) in lieu of traditional four-gland exploration. We hypothesized that Tc-99m sestamibi scan interpretation incorporating numerical measurements on the degree of asymmetrical activity from bilateral thyroid beds can be useful in localizing single adenoma for MIP. We devised a quantitative interpretation method for Tc-99m sestamibi scan based on the numerically graded asymmetrical activity on early phase. The numerical ratio value of each scan was obtained by dividing the number of counts from symmetrically drawn regions of interest (ROI) over bilateral thyroid beds. The final pathology and clinical outcome of 109 patients were used to perform receiver operating curve (ROC) analysis. Receiver operating curve analysis revealed the area under the curve (AUC) was calculated to be 0.71 (P = 0.0032), validating this method as a diagnostic tool. The optimal cut-off point for the ratio value with maximal combined sensitivity and specificity was found with corresponding sensitivity of 67.9% (56.5-77.2%, 95% CI) and specificity of 75.0% (52.8-91.8%, 95% CI). An additional higher cut-off with higher specificity with minimal possible sacrifice on sensitivity was also selected, yielding sensitivity of 28.6% (18.8-38.6%, 95% CI) and specificity of 90.0% (69.6-98.8%, 95% CI). Our results demonstrated that the more asymmetrical activity on the initial phase, the more successful it is to localize a single parathyroid adenoma on sestamibi scans. Using early-phase Tc-99m sestamibi scan only, we were able to select patients for minimally invasive parathyroidectomy with 90% specificity. © 2018 The Royal Australian and New Zealand College of Radiologists.

ADC histogram analysis for adrenal tumor histogram analysis of apparent diffusion coefficient in differentiating adrenal adenoma from pheochromocytoma.

PubMed

Umanodan, Tomokazu; Fukukura, Yoshihiko; Kumagae, Yuichi; Shindo, Toshikazu; Nakajo, Masatoyo; Takumi, Koji; Nakajo, Masanori; Hakamada, Hiroto; Umanodan, Aya; Yoshiura, Takashi

2017-04-01

To determine the diagnostic performance of apparent diffusion coefficient (ADC) histogram analysis in diffusion-weighted (DW) magnetic resonance imaging (MRI) for differentiating adrenal adenoma from pheochromocytoma. We retrospectively evaluated 52 adrenal tumors (39 adenomas and 13 pheochromocytomas) in 47 patients (21 men, 26 women; mean age, 59.3 years; range, 16-86 years) who underwent DW 3.0T MRI. Histogram parameters of ADC (b-values of 0 and 200 [ADC 200 ], 0 and 400 [ADC 400 ], and 0 and 800 s/mm 2 [ADC 800 ])-mean, variance, coefficient of variation (CV), kurtosis, skewness, and entropy-were compared between adrenal adenomas and pheochromocytomas, using the Mann-Whitney U-test. Receiver operating characteristic (ROC) curves for the histogram parameters were generated to differentiate adrenal adenomas from pheochromocytomas. Sensitivity and specificity were calculated by using a threshold criterion that would maximize the average of sensitivity and specificity. Variance and CV of ADC 800 were significantly higher in pheochromocytomas than in adrenal adenomas (P < 0.001 and P = 0.001, respectively). With all b-value combinations, the entropy of ADC was significantly higher in pheochromocytomas than in adrenal adenomas (all P ≤ 0.001), and showed the highest area under the ROC curve among the ADC histogram parameters for diagnosing adrenal adenomas (ADC 200 , 0.82; ADC 400 , 0.87; and ADC 800 , 0.92), with sensitivity of 84.6% and specificity of 84.6% (cutoff, ≤2.82) with ADC 200 ; sensitivity of 89.7% and specificity of 84.6% (cutoff, ≤2.77) with ADC 400 ; and sensitivity of 94.9% and specificity of 92.3% (cutoff, ≤2.67) with ADC 800 . ADC histogram analysis of DW MRI can help differentiate adrenal adenoma from pheochromocytoma. 3 J. Magn. Reson. Imaging 2017;45:1195-1203. © 2016 International Society for Magnetic Resonance in Medicine.

Three new sensitive and specific heat-shock protein 70 PCRs for global Leishmania species identification.

PubMed

Montalvo, A M; Fraga, J; Maes, I; Dujardin, J-C; Van der Auwera, G

2012-07-01

The heat-shock protein 70 gene (hsp70) has been exploited for Leishmania species identification in the New and Old World, using PCR followed by restriction fragment length polymorphism (RFLP) analysis. Current PCR presents limitations in terms of sensitivity, which hampers its use for analyzing clinical and biological samples, and specificity, which makes it inappropriate to discriminate between Leishmania and other trypanosomatids. The aim of the study was to improve the sensitivity and specificity of a previously reported hsp70 PCR using alternative PCR primers and RFLPs. Following in silico analysis of available sequences, three new PCR primer sets and restriction digest schemes were tested on a globally representative panel of 114 Leishmania strains, various other infectious agents, and clinical samples. The largest new PCR fragment retained the discriminatory power from RFLP, while two smaller fragments discriminated less species. The detection limit of the new PCRs was between 0.05 and 0.5 parasite genomes, they amplified clinical samples more efficiently, and were Leishmania specific. We succeeded in significantly improving the specificity and sensitivity of the PCRs for hsp70 Leishmania species typing. The improved PCR-RFLP assays can impact diagnosis, treatment, and epidemiological studies of leishmaniasis in any setting worldwide.

The diagnosis of food allergy: a systematic review and meta-analysis.

PubMed

Soares-Weiser, K; Takwoingi, Y; Panesar, S S; Muraro, A; Werfel, T; Hoffmann-Sommergruber, K; Roberts, G; Halken, S; Poulsen, L; van Ree, R; Vlieg-Boerstra, B J; Sheikh, A

2014-01-01

We investigated the accuracy of tests used to diagnose food allergy. Skin prick tests (SPT), specific-IgE (sIgE), component-resolved diagnosis and the atopy patch test (APT) were compared with the reference standard of double-blind placebo-controlled food challenge. Seven databases were searched and international experts were contacted. Two reviewers independently identified studies, extracted data, and used QUADAS-2 to assess risk of bias. Where possible, meta-analysis was undertaken. Twenty-four (2831 participants) studies were included. For cows' milk allergy, the pooled sensitivities were 53% (95% CI 33-72), 88% (95 % CI 76-94), and 87% (95% CI 75-94), and specificities were 88% (95% CI 76-95), 68% (95% CI 56-77), and 48% (95% CI 36-59) for APT, SPT, and sIgE, respectively. For egg, pooled sensitivities were 92% (95% CI 80-97) and 93% (95% CI 82-98), and specificities were 58% (95% CI 49-67) and 49% (40-58%) for skin prick tests and specific-IgE. For wheat, pooled sensitivities were 73% (95% CI 56-85) and 83% (95% CI 69-92), and specificities were 73% (95% CI 48-89) and 43% (95% CI 20-69%) for SPT and sIgE. For soy, pooled sensitivities were 55% (95% CI 33-75) and 83% (95% CI 64-93), and specificities were 68% (95% CI 52-80) and 38% (95% CI 24-54) for SPT and sIgE. For peanut, pooled sensitivities were 95% (95% CI 88-98) and 96% (95% CI 92-98), and specificities were 61% (95% CI 47-74), and 59% (95% CI 45-72) for SPT and sIgE. The evidence base is limited and weak and is therefore difficult to interpret. Overall, SPT and sIgE appear sensitive although not specific for diagnosing IgE-mediated food allergy. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Sensitivity and specificity of Addenbrooke's Cognitive Examination, Mattis Dementia Rating Scale, Frontal Assessment Battery and Mini Mental State Examination for diagnosing dementia in Parkinson's disease.

PubMed

Kaszás, B; Kovács, N; Balás, I; Kállai, J; Aschermann, Z; Kerekes, Z; Komoly, S; Nagy, F; Janszky, J; Lucza, T; Karádi, K

2012-06-01

Among the non-motor features of Parkinson's disease (PD), cognitive impairment is one of the most troublesome problems. Highly sensitive and specific screening instruments for detecting dementia in PD (PDD) are required in the clinical practice. In our study we evaluated the sensitivity and specificity of different neuropsychological tests (Addenbrooke's Cognitive Examination, ACE; Frontal Assessment Battery, FAB and Mattis Dementia Rating Scale, MDRS) in 73 Parkinson's disease patients without depression. By receiver operating characteristic curve analysis, these screening instruments were tested against the recently established clinical diagnostic criteria of PDD. Best cut-off score for ACE to identify PDD was 80 points (sensitivity = 74.0%, specificity = 78.1%). For FAB the most optimal cut-off value was 12 points (sensitivity = 66.3%, specificity = 72.2%); whereas for MDRS it was 125 points (sensitivity = 89.8%, specificity = 98.3%). Among the examined test batteries, MDRS had the best clinicometric profile for detecting PDD. Although the types of applied screening instruments might differ from movement disorder clinic to clinic within a country, determination of the most specific and sensitive test for the given population remains to be an important task. Our results demonstrated that the specificity and sensitivity of MDRS was better than those of ACE, FAB and MMSE in Hungary. However, further studies with larger sample size and more uniform criteria for participation are required to determine the most suitable screening instrument for cognitive impairment. Copyright © 2012 Elsevier Ltd. All rights reserved.

Enzymatic signal amplification for sensitive detection of intracellular antigens by flow cytometry.

PubMed

Karkmann, U; Radbruch, A; Hölzel, V; Scheffold, A

1999-11-19

Flow cytometry is the method of choice for the analysis of single cells with respect to the expression of specific antigens. Antigens can be detected with specific antibodies either on the cell surface or within the cells, after fixation and permeabilization of the cell membrane. Using conventional fluorochrome-labeled antibodies several thousand antigens are required for clear-cut separation of positive and negative cells. More sensitive reagents, e.g., magnetofluorescent liposomes conjugated to specific antibodies permit the detection of less than 200 molecules per cell but cannot be used for the detection of intracellular antigens. Here, we describe an enzymatic amplification technique (intracellular tyramine-based signal amplification, ITSA) for the sensitive cytometric analysis of intracellular cytokines by immunofluorescence. This approach results in a 10 to 15-fold improvement of the signal-to-noise ratio compared to conventional fluorochrome labeled antibodies and permits the detection of as few as 300-400 intracellular antigens per cell.

Efficient molecular screening of Lynch syndrome by specific 3' promoter methylation of the MLH1 or BRAF mutation in colorectal cancer with high-frequency microsatellite instability.

PubMed

Nakagawa, Hitoshi; Nagasaka, Takeshi; Cullings, Harry M; Notohara, Kenji; Hoshijima, Naoko; Young, Joanne; Lynch, Henry T; Tanaka, Noriaki; Matsubara, Nagahide

2009-06-01

It is sometimes difficult to diagnose Lynch syndrome by the simple but strict clinical criteria, or even by the definitive genetic testing for causative germline mutation of mismatch repair genes. Thus, some practical and efficient screening strategy to select highly possible Lynch syndrome patients is exceedingly desirable. We performed a comprehensive study to evaluate the methylation status of whole MLH1 promoter region by direct bisulfite sequencing of the entire MLH1 promoter regions on Lynch and non-Lynch colorectal cancers (CRCs). Then, we established a convenient assay to detect methylation in key CpG islands responsible for the silencing of MLH1 expression. We studied the methylation status of MLH1 as well as the CpG island methylator phenotype (CIMP) and immunohistochemical analysis of mismatch repair proteins on 16 cases of Lynch CRC and 19 cases of sporadic CRCs with high-frequency microsatellite instability (MSI-H). Sensitivity to detect Lynch syndrome by MLH1 (CCAAT) methylation was 88% and the specificity was 84%. Positive likelihood ratio (PLR) was 5.5 and negative likelihood ratio (NLR) was 0.15. Sensitivity by mutational analysis of BRAF was 100%, specificity was 84%, PLR was 6.3 and NLR was zero. By CIMP analysis; sensitivity was 88%, specificity was 79%, PLR was 4.2, and NLR was 0.16. BRAF mutation or MLH1 methylation analysis combined with MSI testing could be a good alternative to screen Lynch syndrome patients in a cost effective manner. Although the assay for CIMP status also showed acceptable sensitivity and specificity, it may not be practical because of its rather complicated assay.

Optimal cutoff points for HOMA-IR and QUICKI in the diagnosis of metabolic syndrome and non-alcoholic fatty liver disease: A population based study.

PubMed

Motamed, Nima; Miresmail, Seyed Javad Haji; Rabiee, Behnam; Keyvani, Hossein; Farahani, Behzad; Maadi, Mansooreh; Zamani, Farhad

2016-03-01

The present study was carried out to determine the optimal cutoff points for homeostatic model assessment (HOMA-IR) and quantitative insulin sensitivity check index (QUICKI) in the diagnosis of metabolic syndrome (MetS) and non-alcoholic fatty liver disease (NAFLD). The baseline data of 5511 subjects aged ≥18years of a cohort study in northern Iran were utilized to analyze. Receiver operating characteristic (ROC) analysis was conducted to determine the discriminatory capability of HOMA-IR and QUICKI in the diagnosis of MetS and NAFLD. Youden index was utilized to determine the optimal cutoff points of HOMA-IR and QUICKI in the diagnosis of MetS and NAFLD. The optimal cutoff points for HOMA-IR in the diagnosis of MetS and NAFLD were 2.0 [sensitivity=64.4%, specificity=66.8%] and 1.79 [sensitivity=66.2%, specificity=62.2%] in men and were 2.5 [sensitivity=57.6%, specificity=67.9%] and 1.95 [sensitivity=65.1%, specificity=54.7%] in women respectively. Furthermore, the optimal cutoff points for QUICKI in the diagnosis of MetS and NAFLD were 0.343 [sensitivity=63.7%, specificity=67.8%] and 0.347 [sensitivity=62.9%, specificity=65.0%] in men and were 0.331 [sensitivity=55.7%, specificity=70.7%] and 0.333 [sensitivity=53.2%, specificity=67.7%] in women respectively. Not only the optimal cutoff points of HOMA-IR and QUICKI were different for MetS and NAFLD, but also different cutoff points were obtained for men and women for each of these two conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

Simulation-based sensitivity analysis for non-ignorably missing data.

PubMed

Yin, Peng; Shi, Jian Q

2017-01-01

Sensitivity analysis is popular in dealing with missing data problems particularly for non-ignorable missingness, where full-likelihood method cannot be adopted. It analyses how sensitively the conclusions (output) may depend on assumptions or parameters (input) about missing data, i.e. missing data mechanism. We call models with the problem of uncertainty sensitivity models. To make conventional sensitivity analysis more useful in practice we need to define some simple and interpretable statistical quantities to assess the sensitivity models and make evidence based analysis. We propose a novel approach in this paper on attempting to investigate the possibility of each missing data mechanism model assumption, by comparing the simulated datasets from various MNAR models with the observed data non-parametrically, using the K-nearest-neighbour distances. Some asymptotic theory has also been provided. A key step of this method is to plug in a plausibility evaluation system towards each sensitivity parameter, to select plausible values and reject unlikely values, instead of considering all proposed values of sensitivity parameters as in the conventional sensitivity analysis method. The method is generic and has been applied successfully to several specific models in this paper including meta-analysis model with publication bias, analysis of incomplete longitudinal data and mean estimation with non-ignorable missing data.

Rotator cuff crepitus: could Codman really feel a cuff tear?

PubMed

Ponce, Brent A; Kundukulam, Joseph A; Sheppard, Evan D; Determann, Jason R; McGwin, Gerald; Narducci, Carl A; Crowther, Marshall J

2014-07-01

The objective of this study was to assess the accuracy of palpating crepitus to diagnose rotator cuff tears. Seventy consecutive consenting patients who presented with shoulder pain and no previous imaging or surgery on the affected shoulder were prospectively enrolled during a 10-month period. A standardized patient history and examination, including the crepitus test, were recorded in addition to obtaining standard radiographs. Additional imaging after initial evaluation was performed with magnetic resonance imaging and interpreted by a musculoskeletal radiologist blinded to the examination findings. Statistical analysis was used to determine sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the crepitus test in the clinical diagnosis of a rotator cuff tear. Sixty-three patients had histories, examinations, and imaging studies available for analysis. The crepitus test had a sensitivity of 67%, specificity of 80%, PPV of 91%, and NPV of 43% for all types of rotator cuff tears. The sensitivity and specificity for full-thickness or high-grade partial tears was 82% and 73%, respectively; the PPV and NPV were 77% and 79%. Increasing age improved accuracy as the presence of crepitus in patients older than 55 years had a sensitivity of 76%, specificity of 100%, PPV of 100%, and NPV of 38%. The crepitus test has a favorable sensitivity, specificity, PPV, and NPV to assess the integrity of the rotator cuff and may be a useful examination in the clinical diagnosis of a rotator cuff tear. Published by Mosby, Inc.

Mixture models in diagnostic meta-analyses--clustering summary receiver operating characteristic curves accounted for heterogeneity and correlation.

PubMed

Schlattmann, Peter; Verba, Maryna; Dewey, Marc; Walther, Mario

2015-01-01

Bivariate linear and generalized linear random effects are frequently used to perform a diagnostic meta-analysis. The objective of this article was to apply a finite mixture model of bivariate normal distributions that can be used for the construction of componentwise summary receiver operating characteristic (sROC) curves. Bivariate linear random effects and a bivariate finite mixture model are used. The latter model is developed as an extension of a univariate finite mixture model. Two examples, computed tomography (CT) angiography for ruling out coronary artery disease and procalcitonin as a diagnostic marker for sepsis, are used to estimate mean sensitivity and mean specificity and to construct sROC curves. The suggested approach of a bivariate finite mixture model identifies two latent classes of diagnostic accuracy for the CT angiography example. Both classes show high sensitivity but mainly two different levels of specificity. For the procalcitonin example, this approach identifies three latent classes of diagnostic accuracy. Here, sensitivities and specificities are quite different as such that sensitivity increases with decreasing specificity. Additionally, the model is used to construct componentwise sROC curves and to classify individual studies. The proposed method offers an alternative approach to model between-study heterogeneity in a diagnostic meta-analysis. Furthermore, it is possible to construct sROC curves even if a positive correlation between sensitivity and specificity is present. Copyright © 2015 Elsevier Inc. All rights reserved.

Pandemic preparedness in Hawaii: a multicenter verification of real-time RT-PCR for the direct detection of influenza virus types A and B.

PubMed

Whelen, A Christian; Bankowski, Matthew J; Furuya, Glenn; Honda, Stacey; Ueki, Robert; Chan, Amelia; Higa, Karen; Kumashiro, Diane; Moore, Nathaniel; Lee, Roland; Koyamatsu, Terrie; Effler, Paul V

2010-01-01

We integrated multicenter, real-time (RTi) reverse transcription polymerase chain reaction (RT-PCR) screening into a statewide laboratory algorithm for influenza surveillance and response. Each of three sites developed its own testing strategy and was challenged with one randomized and blinded panel of 50 specimens previously tested for respiratory viruses. Following testing, each participating laboratory reported its results to the Hawaii State Department of Health, State Laboratories Division for evaluation and possible discrepant analysis. Two of three laboratories reported a 100% sensitivity and specificity, resulting in a 100% positive predictive value and a 100% negative predictive value (NPV) for influenza type A. The third laboratory showed a 71% sensitivity for influenza type A (83% NPV) with 100% specificity. All three laboratories were 100% sensitive and specific for the detection of influenza type B. Discrepant analysis indicated that the lack of sensitivity experienced by the third laboratory may have been due to the analyte-specific reagent probe used by that laboratory. Use of a newer version of the product with a secondary panel of 20 specimens resulted in a sensitivity and specificity of 100%. All three laboratories successfully verified their ability to conduct clinical testing for influenza using diverse nucleic acid extraction and RTi RT-PCR platforms. Successful completion of the verification by all collaborating laboratories paved the way for the integration of those facilities into a statewide laboratory algorithm for influenza surveillance and response.

Comparison of DWI and 18F-FDG PET/CT for assessing preoperative N-staging in gastric cancer: evidence from a meta-analysis.

PubMed

Luo, Mingxu; Song, Hongmei; Liu, Gang; Lin, Yikai; Luo, Lintao; Zhou, Xin; Chen, Bo

2017-10-13

The diagnostic values of diffusion weighted imaging (DWI) and 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) for N-staging of gastric cancer (GC) were identified and compared. After a systematic search to identify relevant articles, meta-analysis was used to summarize the sensitivities, specificities, and areas under curves (AUCs) for DWI and PET/CT. To better understand the diagnostic utility of DWI and PET/CT for N-staging, the performance of multi-detector computed tomography (MDCT) was used as a reference. Fifteen studies were analyzed. The pooled sensitivity, specificity, and AUC with 95% confidence intervals of DWI were 0.79 (0.73-0.85), 0.69 (0.61-0.77), and 0.81 (0.77-0.84), respectively. For PET/CT, the corresponding values were 0.52 (0.39-0.64), 0.88 (0.61-0.97), and 0.66 (0.62-0.70), respectively. Comparison of the two techniques revealed DWI had higher sensitivity and AUC, but no difference in specificity. DWI exhibited higher sensitivity but lower specificity than MDCT, and 18 F-FDG PET/CT had lower sensitivity and equivalent specificity. Overall, DWI performed better than 18 F-FDG PET/CT for preoperative N-staging in GC. When the efficacy of MDCT was taken as a reference, DWI represented a complementary imaging technique, while 18 F-FDG PET/CT had limited utility for preoperative N-staging.

Sensitivity and specificity of the AdenoPlus point-of-care system in detecting adenovirus in conjunctivitis patients at an ophthalmic emergency department: a diagnostic accuracy study.

PubMed

Kam, K Y Ronald; Ong, Hon Shing; Bunce, Catey; Ogunbowale, Lola; Verma, Seema

2015-09-01

To estimate the diagnostic accuracy (sensitivity and specificity) of the AdenoPlus point-of-care adenoviral test compared to PCR in an ophthalmic accident and emergency service. These findings were compared with those of a previous study. This was a prospective diagnostic accuracy study on 121 patients presenting to an emergency eye unit with a clinical picture of acute adenoviral conjunctivitis. AdenoPlus testing was carried out on one eye of each patient and a PCR analysis was also performed on a swab taken from the same eye. AdenoPlus and PCR results were interpreted by masked personnel. Sensitivity and specificity for the AdenoPlus test were calculated using PCR results as the reference standard. 121 patients were enrolled and 109 met the inclusion criteria. 43 patients (39.4%) tested positive for adenovirus by PCR analysis. The sensitivity of the AdenoPlus swab in detecting adenovirus was 39.5% (17/43, 95% CI 26% to 54%) and specificity was 95.5% (63/66, 95% CI 87% to 98%) compared to PCR. The AdenoPlus test has a high specificity for diagnosing adenoviral conjunctivitis, but in this clinical setting, we could not reproduce the high sensitivity that has been previously published. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

On the Validity and Sensitivity of the Phonics Screening Check: Erratum and Further Analysis

ERIC Educational Resources Information Center

Gilchrist, James M.; Snowling, Margaret J.

2018-01-01

Duff, Mengoni, Bailey and Snowling ("Journal of Research in Reading," 38: 109-123; 2015) evaluated the sensitivity and specificity of the phonics screening check against two reference standards. This report aims to correct a minor data error in the original article and to present further analysis of the data. The methods used are…

The dream of a one-stop-shop: Meta-analysis on myocardial perfusion CT.

PubMed

Pelgrim, Gert Jan; Dorrius, Monique; Xie, Xueqian; den Dekker, Martijn A M; Schoepf, U Joseph; Henzler, Thomas; Oudkerk, Matthijs; Vliegenthart, Rozemarijn

2015-12-01

To determine the diagnostic performance of computed tomography (CT) perfusion techniques for the detection of functionally relevant coronary artery disease (CAD) in comparison to reference standards, including invasive coronary angiography (ICA), single photon emission computed tomography (SPECT), and magnetic resonance imaging (MRI). PubMed, Web of Knowledge and Embase were searched from January 1, 1998 until July 1, 2014. The search yielded 9475 articles. After duplicate removal, 6041 were screened on title and abstract. The resulting 276 articles were independently analyzed in full-text by two reviewers, and included if the inclusion criteria were met. The articles reporting diagnostic parameters including true positive, true negative, false positive and false negative were subsequently evaluated for the meta-analysis. Results were pooled according to CT perfusion technique, namely snapshot techniques: single-phase rest, single-phase stress, single-phase dual-energy stress and combined coronary CT angiography [rest] and single-phase stress, as well the dynamic technique: dynamic stress CT perfusion. Twenty-two articles were included in the meta-analysis (1507 subjects). Pooled per-patient sensitivity and specificity of single-phase rest CT compared to rest SPECT were 89% (95% confidence interval [CI], 82-94%) and 88% (95% CI, 78-94%), respectively. Vessel-based sensitivity and specificity of single-phase stress CT compared to ICA-based >70% stenosis were 82% (95% CI, 64-92%) and 78% (95% CI, 61-89%). Segment-based sensitivity and specificity of single-phase dual-energy stress CT in comparison to stress MRI were 75% (95% CI, 60-85%) and 95% (95% CI, 80-99%). Segment-based sensitivity and specificity of dynamic stress CT perfusion compared to stress SPECT were 77% (95% CI, 67-85) and 89% (95% CI, 78-95%). For combined coronary CT angiography and single-phase stress CT, vessel-based sensitivity and specificity in comparison to ICA-based >50% stenosis were 84% (95% CI, 67-93%) and 93% (95% CI, 89-96%). This meta-analysis shows considerable variation in techniques and reference standards for CT of myocardial blood supply. While CT seems sensitive and specific for evaluation of hemodynamically relevant CAD, studies so far are limited in size. Standardization of myocardial perfusion CT technique is essential. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Efficacy of species-specific recA PCR tests in the identification of Burkholderia cepacia complex environmental isolates.

PubMed

Dalmastri, Claudia; Pirone, Luisa; Tabacchioni, Silvia; Bevivino, Annamaria; Chiarini, Luigi

2005-05-01

In this study, we evaluated if recA species-specific PCR assays could be successfully applied to identify environmental isolates of the widespread Burkholderia cepacia complex (Bcc) species. A total of 729 Bcc rhizosphere isolates collected in different samplings were assigned to the species B. cepacia genomovar I (61), B. cenocepacia recA lineage IIIB (514), B. ambifaria (124) and B. pyrrocinia (30), by means of recA (RFLP) analysis, and PCR tests were performed to assess sensitivity and specificity of recA species-specific primers pairs. B. cepacia genomovar I specific primers produced the expected amplicon with all isolates of the corresponding species (sensitivity, 100%), and cross-reacted with all B. pyrrocinia isolates. On the contrary, B. cenocepacia IIIB primers did not give the expected amplicon in 164 B. cenocepacia IIIB isolates (sensitivity, 68.1%), and isolates of distinct populations showed different sensitivity. B. ambifaria primers failed to amplify a recA-specific fragment only in a few isolates of this species (sensitivity, 93.5%). The absence of specific amplification in a high number of B. cenocepacia rhizosphere isolates indicates that recA specific PCR assays can lead to an underestimation of environmental microorganisms belonging to this bacterial species.

Head-To-Head Comparison Between High- and Standard-b-Value DWI for Detecting Prostate Cancer: A Systematic Review and Meta-Analysis.

PubMed

Woo, Sungmin; Suh, Chong Hyun; Kim, Sang Youn; Cho, Jeong Yeon; Kim, Seung Hyup

2018-01-01

The purpose of this study was to perform a head-to-head comparison between high-b-value (> 1000 s/mm 2 ) and standard-b-value (800-1000 s/mm 2 ) DWI regarding diagnostic performance in the detection of prostate cancer. The MEDLINE and EMBASE databases were searched up to April 1, 2017. The analysis included diagnostic accuracy studies in which high- and standard-b-value DWI were used for prostate cancer detection with histopathologic examination as the reference standard. Methodologic quality was assessed with the revised Quality Assessment of Diagnostic Accuracy Studies tool. Sensitivity and specificity of all studies were calculated and were pooled and plotted in a hierarchic summary ROC plot. Meta-regression and multiple-subgroup analyses were performed to compare the diagnostic performances of high- and standard-b-value DWI. Eleven studies (789 patients) were included. High-b-value DWI had greater pooled sensitivity (0.80 [95% CI, 0.70-0.87]) (p = 0.03) and specificity (0.92 [95% CI, 0.87-0.95]) (p = 0.01) than standard-b-value DWI (sensitivity, 0.78 [95% CI, 0.66-0.86]); specificity, 0.87 [95% CI, 0.77-0.93] (p < 0.01). Multiple-subgroup analyses showed that specificity was consistently higher for high- than for standard-b-value DWI (p ≤ 0.05). Sensitivity was significantly higher for high- than for standard-b-value DWI only in the following subgroups: peripheral zone only, transition zone only, multiparametric protocol (DWI and T2-weighted imaging), visual assessment of DW images, and per-lesion analysis (p ≤ 0.04). In a head-to-head comparison, high-b-value DWI had significantly better sensitivity and specificity for detection of prostate cancer than did standard-b-value DWI. Multiple-subgroup analyses showed that specificity was consistently superior for high-b-value DWI.

Value of circulating cell-free DNA analysis as a diagnostic tool for breast cancer: a meta-analysis

PubMed Central

Ma, Xuelei; Zhang, Jing; Hu, Xiuying

2017-01-01

Objectives The aim of this study was to systematically evaluate the diagnostic value of cell free DNA (cfDNA) for breast cancer. Results Among 308 candidate articles, 25 with relevant diagnostic screening qualified for final analysis. The mean sensitivity, specificity and area under the curve (AUC) of SROC plots for 24 studies that distinguished breast cancer patients from healthy controls were 0.70, 0.87, and 0.9314, yielding a DOR of 32.31. When analyzed in subgroups, the 14 quantitative studies produced sensitivity, specificity, AUC, and a DOR of 0.78, 0.83, 0.9116, and 24.40. The 10 qualitative studies produced 0.50, 0.98, 0.9919, and 68.45. For 8 studies that distinguished malignant breast cancer from benign diseases, the specificity, sensitivity, AUC and DOR were 0.75, 0.79, 0.8213, and 9.49. No covariate factors had a significant correlation with relative DOR. Deek's funnel plots indicated an absence of publication bias. Materials and Methods Databases were searched for studies involving the use of cfDNA to diagnose breast cancer. The studies were analyzed to determine sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio (DOR), and the summary receiver operating characteristic (SROC). Covariates were evaluated for effect on relative DOR. Deek's Funnel plots were generated to measure publication bias. Conclusions Our analysis suggests a promising diagnostic potential of using cfDNA for breast cancer screening, but this diagnostic method is not yet independently sufficient. Further work refining qualitative cfDNA assays will improve the correct diagnosis of breast cancers. PMID:28460452

Diagnostic potential of real-time elastography (RTE) and shear wave elastography (SWE) to differentiate benign and malignant thyroid nodules: A systematic review and meta-analysis.

PubMed

Hu, Xiangdong; Liu, Yujiang; Qian, Linxue

2017-10-01

Real-time elastography (RTE) and shear wave elastography (SWE) are noninvasive and easily available imaging techniques that measure the tissue strain, and it has been reported that the sensitivity and the specificity of elastography were better in differentiating between benign and malignant thyroid nodules than conventional technologies. Relevant articles were searched in multiple databases; the comparison of elasticity index (EI) was conducted with the Review Manager 5.0. Forest plots of the sensitivity and specificity and SROC curve of RTE and SWE were performed with STATA 10.0 software. In addition, sensitivity analysis and bias analysis of the studies were conducted to examine the quality of articles; and to estimate possible publication bias, funnel plot was used and the Egger test was conducted. Finally 22 articles which eventually satisfied the inclusion criteria were included in this study. After eliminating the inefficient, benign and malignant nodules were 2106 and 613, respectively. The meta-analysis suggested that the difference of EI between benign and malignant nodules was statistically significant (SMD = 2.11, 95% CI [1.67, 2.55], P < .00001). The overall sensitivities of RTE and SWE were roughly comparable, whereas the difference of specificities between these 2 methods was statistically significant. In addition, statistically significant difference of AUC between RTE and SWE was observed between RTE and SWE (P < .01). The specificity of RTE was statistically higher than that of SWE; which suggests that compared with SWE, RTE may be more accurate on differentiating benign and malignant thyroid nodules.

Systematic review and meta-analysis of the performance of clinical risk assessment instruments for screening for osteoporosis or low bone density

PubMed Central

Edwards, D. L.; Saleh, A. A.; Greenspan, S. L.

2015-01-01

Summary We performed a systematic review and meta-analysis of the performance of clinical risk assessment instruments for screening for DXA-determined osteoporosis or low bone density. Commonly evaluated risk instruments showed high sensitivity approaching or exceeding 90 % at particular thresholds within various populations but low specificity at thresholds required for high sensitivity. Simpler instruments, such as OST, generally performed as well as or better than more complex instruments. Introduction The purpose of the study is to systematically review the performance of clinical risk assessment instruments for screening for dual-energy X-ray absorptiometry (DXA)-determined osteoporosis or low bone density. Methods Systematic review and meta-analysis were performed. Multiple literature sources were searched, and data extracted and analyzed from included references. Results One hundred eight references met inclusion criteria. Studies assessed many instruments in 34 countries, most commonly the Osteoporosis Self-Assessment Tool (OST), the Simple Calculated Osteoporosis Risk Estimation (SCORE) instrument, the Osteoporosis Self-Assessment Tool for Asians (OSTA), the Osteoporosis Risk Assessment Instrument (ORAI), and body weight criteria. Meta-analyses of studies evaluating OST using a cutoff threshold of <1 to identify US postmenopausal women with osteoporosis at the femoral neck provided summary sensitivity and specificity estimates of 89 % (95%CI 82–96 %) and 41 % (95%CI 23–59 %), respectively. Meta-analyses of studies evaluating OST using a cutoff threshold of 3 to identify US men with osteoporosis at the femoral neck, total hip, or lumbar spine provided summary sensitivity and specificity estimates of 88 % (95%CI 79–97 %) and 55 % (95%CI 42–68 %), respectively. Frequently evaluated instruments each had thresholds and populations for which sensitivity for osteoporosis or low bone mass detection approached or exceeded 90 % but always with a trade-off of relatively low specificity. Conclusions Commonly evaluated clinical risk assessment instruments each showed high sensitivity approaching or exceeding 90 % for identifying individuals with DXA-determined osteoporosis or low BMD at certain thresholds in different populations but low specificity at thresholds required for high sensitivity. Simpler instruments, such as OST, generally performed as well as or better than more complex instruments. PMID:25644147

Biochemical analysis of force-sensitive responses using a large-scale cell stretch device.

PubMed

Renner, Derrick J; Ewald, Makena L; Kim, Timothy; Yamada, Soichiro

2017-09-03

Physical force has emerged as a key regulator of tissue homeostasis, and plays an important role in embryogenesis, tissue regeneration, and disease progression. Currently, the details of protein interactions under elevated physical stress are largely missing, therefore, preventing the fundamental, molecular understanding of mechano-transduction. This is in part due to the difficulty isolating large quantities of cell lysates exposed to force-bearing conditions for biochemical analysis. We designed a simple, easy-to-fabricate, large-scale cell stretch device for the analysis of force-sensitive cell responses. Using proximal biotinylation (BioID) analysis or phospho-specific antibodies, we detected force-sensitive biochemical changes in cells exposed to prolonged cyclic substrate stretch. For example, using promiscuous biotin ligase BirA* tagged α-catenin, the biotinylation of myosin IIA increased with stretch, suggesting the close proximity of myosin IIA to α-catenin under a force bearing condition. Furthermore, using phospho-specific antibodies, Akt phosphorylation was reduced upon stretch while Src phosphorylation was unchanged. Interestingly, phosphorylation of GSK3β, a downstream effector of Akt pathway, was also reduced with stretch, while the phosphorylation of other Akt effectors was unchanged. These data suggest that the Akt-GSK3β pathway is force-sensitive. This simple cell stretch device enables biochemical analysis of force-sensitive responses and has potential to uncover molecules underlying mechano-transduction.

Record of hospitalizations for ambulatory care sensitive conditions: validation of the hospital information system.

PubMed

Rehem, Tania Cristina Morais Santa Barbara; de Oliveira, Maria Regina Fernandes; Ciosak, Suely Itsuko; Egry, Emiko Yoshikawa

2013-01-01

To estimate the sensitivity, specificity and positive and negative predictive values of the Unified Health System's Hospital Information System for the appropriate recording of hospitalizations for ambulatory care-sensitive conditions. The hospital information system records for conditions which are sensitive to ambulatory care, and for those which are not, were considered for analysis, taking the medical records as the gold standard. Through simple random sampling, a sample of 816 medical records was defined and selected by means of a list of random numbers using the Statistical Package for Social Sciences. The sensitivity was 81.89%, specificity was 95.19%, the positive predictive value was 77.61% and the negative predictive value was 96.27%. In the study setting, the Hospital Information System (SIH) was more specific than sensitive, with nearly 20% of care sensitive conditions not detected. There are no validation studies in Brazil of the Hospital Information System records for the hospitalizations which are sensitive to primary health care. These results are relevant when one considers that this system is one of the bases for assessment of the effectiveness of primary health care.

Value of high-sensitivity C-reactive protein assays in predicting atrial fibrillation recurrence: a systematic review and meta-analysis.

PubMed

Yo, Chia-Hung; Lee, Si-Huei; Chang, Shy-Shin; Lee, Matthew Chien-Hung; Lee, Chien-Chang

2014-02-20

We performed a systematic review and meta-analysis of studies on high-sensitivity C-reactive protein (hs-CRP) assays to see whether these tests are predictive of atrial fibrillation (AF) recurrence after cardioversion. Systematic review and meta-analysis. PubMed, EMBASE and Cochrane databases as well as a hand search of the reference lists in the retrieved articles from inception to December 2013. This review selected observational studies in which the measurements of serum CRP were used to predict AF recurrence. An hs-CRP assay was defined as any CRP test capable of measuring serum CRP to below 0.6 mg/dL. We summarised test performance characteristics with the use of forest plots, hierarchical summary receiver operating characteristic curves and bivariate random effects models. Meta-regression analysis was performed to explore the source of heterogeneity. We included nine qualifying studies comprising a total of 347 patients with AF recurrence and 335 controls. A CRP level higher than the optimal cut-off point was an independent predictor of AF recurrence after cardioversion (summary adjusted OR: 3.33; 95% CI 2.10 to 5.28). The estimated pooled sensitivity and specificity for hs-CRP was 71.0% (95% CI 63% to 78%) and 72.0% (61% to 81%), respectively. Most studies used a CRP cut-off point of 1.9 mg/L to predict long-term AF recurrence (77% sensitivity, 65% specificity), and 3 mg/L to predict short-term AF recurrence (73% sensitivity, 71% specificity). hs-CRP assays are moderately accurate in predicting AF recurrence after successful cardioversion.

The Volatility of Data Space: Topology Oriented Sensitivity Analysis

PubMed Central

Du, Jing; Ligmann-Zielinska, Arika

2015-01-01

Despite the difference among specific methods, existing Sensitivity Analysis (SA) technologies are all value-based, that is, the uncertainties in the model input and output are quantified as changes of values. This paradigm provides only limited insight into the nature of models and the modeled systems. In addition to the value of data, a potentially richer information about the model lies in the topological difference between pre-model data space and post-model data space. This paper introduces an innovative SA method called Topology Oriented Sensitivity Analysis, which defines sensitivity as the volatility of data space. It extends SA into a deeper level that lies in the topology of data. PMID:26368929

A blood tumor marker combination assay produces high sensitivity and specificity for cancer according to the natural history.

PubMed

Kobayashi, Tsuneo

2018-03-01

Diagnosis using a specific tumor marker is difficult because the sensitivity of this detection method is under 20%. Herein, a tumor marker combination assay, combining growth-related tumor marker and associated tumor marker (Cancer, 73(7), 1994), was employed. This double-blind tumor marker combination assay (TMCA) showed 87.5% sensitivity as the results, but a low specificity, ranging from 30 to 76%. To overcome this low specificity, we exploited complex markers, a multivariate analysis and serum fractionation by biochemical biopsy. Thus, in this study, a combination of new techniques was used to re-evaluate these serum samples. Three serum panels, containing 90, 120, and 97 samples were obtained from the Mayo Clinic. The final results showed 80-90% sensitivity, 84-85% specificity, and 83-88% accuracy. We demonstrated a notable tumor marker combination assay with high accuracy. This TMCA should be applicable for primary cancer detection and recurrence prevention. © 2018 The Author. Cancer Medicine published by John Wiley & Sons Ltd.

Real-time polymerase chain reaction for diagnosing infectious mononucleosis in pediatric patients: A systematic review and meta-analysis.

PubMed

Jiang, Sha-Yi; Yang, Jing-Wei; Shao, Jing-Bo; Liao, Xue-Lian; Lu, Zheng-Hua; Jiang, Hui

2016-05-01

In this meta-analysis, we evaluated the diagnostic role of Epstein-Barr virus deoxyribonucleic acid detection and quantitation in the serum of pediatric and young adult patients with infectious mononucleosis. The primary outcome of this meta-analysis was the sensitivity and specificity of Epstein-Barr virus (EBV) deoxyribonucleic acid (DNA) detection and quantitation using polymerase chain reaction (PCR). A systematic review and meta-analysis was performed by searching for articles that were published through September 24, 2014 in the following databases: Medline, Cochrane, EMBASE, and Google Scholar. The following keywords were used for the search: "Epstein-Barr virus," "infectious mononucleosis," "children/young adults/infant/pediatric," and "polymerase chain reaction or PCR." Three were included in this analysis. We found that for detection by PCR, the pooled sensitivity for detecting EBV DNA was 77% (95%CI, 66-86%) and the pooled specificity for was 98% (95%CI, 93-100%). Our findings indicate that this PCR-based assay has high specificity and good sensitivity for detecting of EBV DNA, indicating it may useful for identifying patients with infectious mononucleosis. This assay may also be helpful to identify young athletic patients or highly physically active pediatric patients who are at risk for a splenic rupture due to acute infectious mononucleosis. © 2015 Wiley Periodicals, Inc.

Evaluation of quantitative image analysis criteria for the high-resolution microendoscopic detection of neoplasia in Barrett's esophagus

NASA Astrophysics Data System (ADS)

Muldoon, Timothy J.; Thekkek, Nadhi; Roblyer, Darren; Maru, Dipen; Harpaz, Noam; Potack, Jonathan; Anandasabapathy, Sharmila; Richards-Kortum, Rebecca

2010-03-01

Early detection of neoplasia in patients with Barrett's esophagus is essential to improve outcomes. The aim of this ex vivo study was to evaluate the ability of high-resolution microendoscopic imaging and quantitative image analysis to identify neoplastic lesions in patients with Barrett's esophagus. Nine patients with pathologically confirmed Barrett's esophagus underwent endoscopic examination with biopsies or endoscopic mucosal resection. Resected fresh tissue was imaged with fiber bundle microendoscopy; images were analyzed by visual interpretation or by quantitative image analysis to predict whether the imaged sites were non-neoplastic or neoplastic. The best performing pair of quantitative features were chosen based on their ability to correctly classify the data into the two groups. Predictions were compared to the gold standard of histopathology. Subjective analysis of the images by expert clinicians achieved average sensitivity and specificity of 87% and 61%, respectively. The best performing quantitative classification algorithm relied on two image textural features and achieved a sensitivity and specificity of 87% and 85%, respectively. This ex vivo pilot trial demonstrates that quantitative analysis of images obtained with a simple microendoscope system can distinguish neoplasia in Barrett's esophagus with good sensitivity and specificity when compared to histopathology and to subjective image interpretation.

Detection of somatic mutations by high-resolution DNA melting (HRM) analysis in multiple cancers.

PubMed

Gonzalez-Bosquet, Jesus; Calcei, Jacob; Wei, Jun S; Garcia-Closas, Montserrat; Sherman, Mark E; Hewitt, Stephen; Vockley, Joseph; Lissowska, Jolanta; Yang, Hannah P; Khan, Javed; Chanock, Stephen

2011-01-17

Identification of somatic mutations in cancer is a major goal for understanding and monitoring the events related to cancer initiation and progression. High resolution melting (HRM) curve analysis represents a fast, post-PCR high-throughput method for scanning somatic sequence alterations in target genes. The aim of this study was to assess the sensitivity and specificity of HRM analysis for tumor mutation screening in a range of tumor samples, which included 216 frozen pediatric small rounded blue-cell tumors as well as 180 paraffin-embedded tumors from breast, endometrial and ovarian cancers (60 of each). HRM analysis was performed in exons of the following candidate genes known to harbor established commonly observed mutations: PIK3CA, ERBB2, KRAS, TP53, EGFR, BRAF, GATA3, and FGFR3. Bi-directional sequencing analysis was used to determine the accuracy of the HRM analysis. For the 39 mutations observed in frozen samples, the sensitivity and specificity of HRM analysis were 97% and 87%, respectively. There were 67 mutation/variants in the paraffin-embedded samples, and the sensitivity and specificity for the HRM analysis were 88% and 80%, respectively. Paraffin-embedded samples require higher quantity of purified DNA for high performance. In summary, HRM analysis is a promising moderate-throughput screening test for mutations among known candidate genomic regions. Although the overall accuracy appears to be better in frozen specimens, somatic alterations were detected in DNA extracted from paraffin-embedded samples.

Detection of Somatic Mutations by High-Resolution DNA Melting (HRM) Analysis in Multiple Cancers

PubMed Central

Gonzalez-Bosquet, Jesus; Calcei, Jacob; Wei, Jun S.; Garcia-Closas, Montserrat; Sherman, Mark E.; Hewitt, Stephen; Vockley, Joseph; Lissowska, Jolanta; Yang, Hannah P.; Khan, Javed; Chanock, Stephen

2011-01-01

Identification of somatic mutations in cancer is a major goal for understanding and monitoring the events related to cancer initiation and progression. High resolution melting (HRM) curve analysis represents a fast, post-PCR high-throughput method for scanning somatic sequence alterations in target genes. The aim of this study was to assess the sensitivity and specificity of HRM analysis for tumor mutation screening in a range of tumor samples, which included 216 frozen pediatric small rounded blue-cell tumors as well as 180 paraffin-embedded tumors from breast, endometrial and ovarian cancers (60 of each). HRM analysis was performed in exons of the following candidate genes known to harbor established commonly observed mutations: PIK3CA, ERBB2, KRAS, TP53, EGFR, BRAF, GATA3, and FGFR3. Bi-directional sequencing analysis was used to determine the accuracy of the HRM analysis. For the 39 mutations observed in frozen samples, the sensitivity and specificity of HRM analysis were 97% and 87%, respectively. There were 67 mutation/variants in the paraffin-embedded samples, and the sensitivity and specificity for the HRM analysis were 88% and 80%, respectively. Paraffin-embedded samples require higher quantity of purified DNA for high performance. In summary, HRM analysis is a promising moderate-throughput screening test for mutations among known candidate genomic regions. Although the overall accuracy appears to be better in frozen specimens, somatic alterations were detected in DNA extracted from paraffin-embedded samples. PMID:21264207

Application of support vector machine method for the analysis of absorption spectra of exhaled air of patients with broncho-pulmonary diseases

NASA Astrophysics Data System (ADS)

Bukreeva, Ekaterina B.; Bulanova, Anna A.; Kistenev, Yury V.; Kuzmin, Dmitry A.; Tuzikov, Sergei A.; Yumov, Evgeny L.

2014-11-01

The results of the joint use of laser photoacoustic spectroscopy and chemometrics methods in gas analysis of exhaled air of patients with respiratory diseases (chronic obstructive pulmonary disease, pneumonia and lung cancer) are presented. The absorption spectra of exhaled breath of all volunteers were measured, the classification methods of the scans of the absorption spectra were applied, the sensitivity/specificity of the classification results were determined. It were obtained a result of nosological in pairs classification for all investigated volunteers, indices of sensitivity and specificity.

Monoallelic mutation analysis (MAMA) for identifying germline mutations.

PubMed

Papadopoulos, N; Leach, F S; Kinzler, K W; Vogelstein, B

1995-09-01

Dissection of germline mutations in a sensitive and specific manner presents a continuing challenge. In dominantly inherited diseases, mutations occur in only one allele and are often masked by the normal allele. Here we report the development of a sensitive and specific diagnostic strategy based on somatic cell hybridization termed MAMA (monoallelic mutation analysis). We have demonstrated the utility of this strategy in two different hereditary colorectal cancer syndromes, one caused by a defective tumour suppressor gene on chromosome 5 (familial adenomatous polyposis, FAP) and the other caused by a defective mismatch repair gene on chromosome 2 (hereditary non-polyposis colorectal cancer, HNPCC).

Standardized Index of Shape (DCE-MRI) and Standardized Uptake Value (PET/CT): Two quantitative approaches to discriminate chemo-radiotherapy locally advanced rectal cancer responders under a functional profile

PubMed Central

Petrillo, Antonella; Fusco, Roberta; Petrillo, Mario; Granata, Vincenza; Delrio, Paolo; Bianco, Francesco; Pecori, Biagio; Botti, Gerardo; Tatangelo, Fabiana; Caracò, Corradina; Aloj, Luigi; Avallone, Antonio; Lastoria, Secondo

2017-01-01

Purpose To investigate dynamic contrast enhanced-MRI (DCE-MRI) in the preoperative chemo-radiotherapy (CRT) assessment for locally advanced rectal cancer (LARC) compared to18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). Methods 75 consecutive patients with LARC were enrolled in a prospective study. DCE-MRI analysis was performed measuring SIS: linear combination of percentage change (Δ) of maximum signal difference (MSD) and wash-out slope (WOS). 18F-FDG PET/CT analysis was performed using SUV maximum (SUVmax). Tumor regression grade (TRG) were estimated after surgery. Non-parametric tests, receiver operating characteristic were evaluated. Results 55 patients (TRG1-2) were classified as responders while 20 subjects as non responders. ΔSIS reached sensitivity of 93%, specificity of 80% and accuracy of 89% (cut-off 6%) to differentiate responders by non responders, sensitivity of 93%, specificity of 69% and accuracy of 79% (cut-off 30%) to identify pathological complete response (pCR). Therapy assessment via ΔSUVmax reached sensitivity of 67%, specificity of 75% and accuracy of 70% (cut-off 60%) to differentiate responders by non responders and sensitivity of 80%, specificity of 31% and accuracy of 51% (cut-off 44%) to identify pCR. Conclusions CRT response assessment by DCE-MRI analysis shows a higher predictive ability than 18F-FDG PET/CT in LARC patients allowing to better discriminate significant and pCR. PMID:28042958

Standardized Index of Shape (DCE-MRI) and Standardized Uptake Value (PET/CT): Two quantitative approaches to discriminate chemo-radiotherapy locally advanced rectal cancer responders under a functional profile.

PubMed

Petrillo, Antonella; Fusco, Roberta; Petrillo, Mario; Granata, Vincenza; Delrio, Paolo; Bianco, Francesco; Pecori, Biagio; Botti, Gerardo; Tatangelo, Fabiana; Caracò, Corradina; Aloj, Luigi; Avallone, Antonio; Lastoria, Secondo

2017-01-31

To investigate dynamic contrast enhanced-MRI (DCE-MRI) in the preoperative chemo-radiotherapy (CRT) assessment for locally advanced rectal cancer (LARC) compared to18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). 75 consecutive patients with LARC were enrolled in a prospective study. DCE-MRI analysis was performed measuring SIS: linear combination of percentage change (Δ) of maximum signal difference (MSD) and wash-out slope (WOS). 18F-FDG PET/CT analysis was performed using SUV maximum (SUVmax). Tumor regression grade (TRG) were estimated after surgery. Non-parametric tests, receiver operating characteristic were evaluated. 55 patients (TRG1-2) were classified as responders while 20 subjects as non responders. ΔSIS reached sensitivity of 93%, specificity of 80% and accuracy of 89% (cut-off 6%) to differentiate responders by non responders, sensitivity of 93%, specificity of 69% and accuracy of 79% (cut-off 30%) to identify pathological complete response (pCR). Therapy assessment via ΔSUVmax reached sensitivity of 67%, specificity of 75% and accuracy of 70% (cut-off 60%) to differentiate responders by non responders and sensitivity of 80%, specificity of 31% and accuracy of 51% (cut-off 44%) to identify pCR. CRT response assessment by DCE-MRI analysis shows a higher predictive ability than 18F-FDG PET/CT in LARC patients allowing to better discriminate significant and pCR.

Sensitivity assessment of freshwater macroinvertebrates to pesticides using biological traits.

PubMed

Ippolito, A; Todeschini, R; Vighi, M

2012-03-01

Assessing the sensitivity of different species to chemicals is one of the key points in predicting the effects of toxic compounds in the environment. Trait-based predicting methods have proved to be extremely efficient for assessing the sensitivity of macroinvertebrates toward compounds with non specific toxicity (narcotics). Nevertheless, predicting the sensitivity of organisms toward compounds with specific toxicity is much more complex, since it depends on the mode of action of the chemical. The aim of this work was to predict the sensitivity of several freshwater macroinvertebrates toward three classes of plant protection products: organophosphates, carbamates and pyrethroids. Two databases were built: one with sensitivity data (retrieved, evaluated and selected from the U.S. Environmental Protection Agency ECOTOX database) and the other with biological traits. Aside from the "traditional" traits usually considered in ecological analysis (i.e. body size, respiration technique, feeding habits, etc.), multivariate analysis was used to relate the sensitivity of organisms to some other characteristics which may be involved in the process of intoxication. Results confirmed that, besides traditional biological traits, related to uptake capability (e.g. body size and body shape) some traits more related to particular metabolic characteristics or patterns have a good predictive capacity on the sensitivity to these kinds of toxic substances. For example, behavioral complexity, assumed as an indicator of nervous system complexity, proved to be an important predictor of sensitivity towards these compounds. These results confirm the need for more complex traits to predict effects of highly specific substances. One key point for achieving a complete mechanistic understanding of the process is the choice of traits, whose role in the discrimination of sensitivity should be clearly interpretable, and not only statistically significant.

Intergrated Systems Biology Approach for Ovarian Cancer Biomarker Discovery — EDRN Public Portal

Cancer.gov

The overall objective is to validate serum protein markers for early diagnosis of ovarian cancer with the ultimate goal being to develop a multiparametric panel consisting of 2-4 novel markers with 10 known markers for phase 3 analysis. In phase 1, we will screen for markers able to pass a threshold of 98% specificity and 30% sensitivity in a cohort of 300 women. Markers that pass phase 1 validation will be investigated in a phase 2 PRoBE cohort with a 98% specificity and 70% sensitivity cut-off. Finally, markers that pass phase 2 validation will be evaluated in EDRN CVC laboratory specimens with a cut-off of > 98% specificity and 90% sensitivity.

Prostate Specific Membrane Antigen Positron Emission Tomography May Improve the Diagnostic Accuracy of Multiparametric Magnetic Resonance Imaging in Localized Prostate Cancer.

PubMed

Rhee, H; Thomas, P; Shepherd, B; Gustafson, S; Vela, I; Russell, P J; Nelson, C; Chung, E; Wood, G; Malone, G; Wood, S; Heathcote, P

2016-10-01

Positron emission tomography using ligands targeting prostate specific membrane antigen has recently been introduced. Positron emission tomography imaging with (68)Ga-PSMA-HBED-CC has been shown to detect metastatic prostate cancer lesions at a high rate. In this study we compare multiparametric magnetic resonance imaging and prostate specific membrane antigen positron emission tomography of the prostate with whole mount ex vivo prostate histopathology to determine the true sensitivity and specificity of these imaging modalities for detecting and locating tumor foci within the prostate. In a prospective clinical trial setting 20 patients with localized prostate cancer and a planned radical prostatectomy were recruited. All patients underwent multiparametric magnetic resonance imaging and positron emission tomography before surgery, and whole mount histopathology slides were directly compared to the images. European Society of Urogenital Radiology guidelines for reporting magnetic resonance imaging were used as a template for regional units of analysis. The uropathologist and radiologists were blinded to individual components of the study, and the final correlation was performed by visual and deformable registration analysis. A total of 50 clinically significant lesions were identified from the whole mount histopathological analysis. Based on regional analysis the sensitivity, specificity, positive predictive value and negative predictive value for multiparametric magnetic resonance imaging were 44%, 94%, 81% and 76%, respectively. With prostate specific membrane antigen positron emission tomography the sensitivity, specificity, positive predictive value and negative predictive value were 49%, 95%, 85% and 88%, respectively. Prostate specific membrane antigen positron emission tomography yielded a higher specificity and positive predictive value. A significant proportion of cancers are potentially missed and underestimated by both imaging modalities. Prostate specific membrane antigen positron emission tomography may be used in addition to multiparametric magnetic resonance imaging to help improve local staging in those patients undergoing retropubic radical prostatectomy. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Remembering rejection: specificity and linguistic styles of autobiographical memories in borderline personality disorder and depression.

PubMed

Rosenbach, Charlotte; Renneberg, Babette

2015-03-01

High levels of rejection sensitivity are assumed to be the result of early and prolonged experiences of rejection. Aim of this study was to investigate autobiographical memories of rejection in clinical samples high in rejection sensitivity (Borderline Personality Disorder, BPD, and Major Depressive Disorder, MDD) and to identify group differences in the quality of the memories. Memories of rejection were retrieved using an adapted version of the Autobiographical Memory Test (AMT; five positive cue words, five cue words referring to rejection). Specificity of memories and linguistic word usage was analyzed in 30 patients with BPD, 27 patients with MDD and 30 healthy controls. Patients with BPD retrieved less specific memories compared to the healthy control group, whereas patients with MDD did not differ from controls in this regard. The group difference was no longer significant when controlling for rejection sensitivity. Linguistic analysis indicated that compared to both other groups, patients with BPD showed a higher self-focus, used more anger-related words, referred more frequently to social environments, and rated memories of rejection as more relevant for today's life. Clinical symptoms were not assessed in the control group. Moreover, the written form of the AMT might reduce the total number of specific memories. The level of rejection sensitivity influenced the specificity of the retrieved memories. Analysis of linguistic styles revealed specific linguistic patterns in BPD compared to non-clinical as well as depressed participants. Copyright © 2014 Elsevier Ltd. All rights reserved.

Assessment of insulin sensitivity by the hyperinsulinemic euglycemic clamp: Comparison with the spectral analysis of photoplethysmography.

PubMed

De Souza, Aglecio Luiz; Batista, Gisele Almeida; Alegre, Sarah Monte

2017-01-01

We compare spectral analysis of photoplethysmography (PTG) with insulin resistance measured by the hyperinsulinemic euglycemic clamp (HEC) technique. A total of 100 nondiabetic subjects, 43 men and 57 women aged 20-63years, 30 lean, 42 overweight and 28 obese were enrolled in the study. These patients underwent an examination with HEC, and an examination with the PTG spectral analysis and calculation of the PTG Total Power (PTG-TP). Receiver-operating characteristic (ROC) curves were constructed to determine the specificity and sensitivity of PTG-TP in the assessment of insulin resistance. There is a moderate correlation between insulin sensitivity (M-value) and PTG-TP (r=- 0.64, p<0.0001). The ROC curves showed that the most relevant cutoff to the whole study group was a PTG-TP>406.2. This cut-off had a sensitivity=95.7%, specificity =84,4% and the area under the ROC curve (AUC)=0.929 for identifying insulin resistance. All AUC ROC curve analysis were significant (p<0.0001). The use of the PTG-TP marker measured from the PTG spectral analysis is a useful tool in screening and follow up of IR, especially in large-scale studies. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Aberrant DNA methylation of tumor-related genes in oral rinse: a noninvasive method for detection of oral squamous cell carcinoma.

PubMed

Nagata, Satoshi; Hamada, Tomofumi; Yamada, Norishige; Yokoyama, Seiya; Kitamoto, Sho; Kanmura, Yuji; Nomura, Masahiro; Kamikawa, Yoshiaki; Yonezawa, Suguru; Sugihara, Kazumasa

2012-09-01

The early detection of oral squamous cell carcinoma (OSCC) is important, and a screening test with high sensitivity and specificity is urgently needed. Therefore, in this study, the authors investigated the methylation status of tumor-related genes with the objective of establishing a noninvasive method for the detection of OSCC. Oral rinse samples were obtained from 34 patients with OSCC and from 24 healthy individuals (controls). The methylation status of 13 genes was determined by using methylation-specific polymerase chain reaction analysis and was quantified using a microchip electrophoresis system. Promoter methylation in each participant was screened by receiver operating characteristic analysis, and the utility of each gene's methylation status, alone and in combination with other genes, was evaluated as a tool for oral cancer detection. Eight of the 13 genes had significantly higher levels of DNA methylation in samples from patients with OSCC than in controls. The genes E-cadherin (ECAD), transmembrane protein with epidermal growth factor-like and 2 follistatin-like domains 2 (TMEFF2), retinoic acid receptor beta (RARβ), and O-6 methylguanine DNA methyltransferase (MGMT) had high sensitivity (>75%) and specificity for the detection of oral cancer. OSCC was detected with 100% sensitivity and 87.5% specificity using a combination of ECAD, TMEFF2, RARβ, and MGMT and with 97.1% sensitivity and 91.7% specificity using a combination of ECAD, TMEFF2, and MGMT. The aberrant methylation of a combination of marker genes present in oral rinse samples was used to detect OSCC with >90% sensitivity and specificity. The detection of methylated marker genes from oral rinse samples has great potential for the noninvasive detection of OSCC. Copyright © 2012 American Cancer Society.

Comparison of DWI and 18F-FDG PET/CT for assessing preoperative N-staging in gastric cancer: evidence from a meta-analysis

PubMed Central

Luo, Mingxu; Song, Hongmei; Liu, Gang; Lin, Yikai; Luo, Lintao; Zhou, Xin; Chen, Bo

2017-01-01

The diagnostic values of diffusion weighted imaging (DWI) and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) for N-staging of gastric cancer (GC) were identified and compared. After a systematic search to identify relevant articles, meta-analysis was used to summarize the sensitivities, specificities, and areas under curves (AUCs) for DWI and PET/CT. To better understand the diagnostic utility of DWI and PET/CT for N-staging, the performance of multi-detector computed tomography (MDCT) was used as a reference. Fifteen studies were analyzed. The pooled sensitivity, specificity, and AUC with 95% confidence intervals of DWI were 0.79 (0.73–0.85), 0.69 (0.61–0.77), and 0.81 (0.77–0.84), respectively. For PET/CT, the corresponding values were 0.52 (0.39–0.64), 0.88 (0.61–0.97), and 0.66 (0.62–0.70), respectively. Comparison of the two techniques revealed DWI had higher sensitivity and AUC, but no difference in specificity. DWI exhibited higher sensitivity but lower specificity than MDCT, and 18F-FDG PET/CT had lower sensitivity and equivalent specificity. Overall, DWI performed better than 18F-FDG PET/CT for preoperative N-staging in GC. When the efficacy of MDCT was taken as a reference, DWI represented a complementary imaging technique, while 18F-FDG PET/CT had limited utility for preoperative N-staging. PMID:29137440

Accuracy of line probe assays for the diagnosis of pulmonary and multidrug-resistant tuberculosis: a systematic review and meta-analysis

PubMed Central

Cudahy, Patrick G.T; Schumacher, Samuel G.; Steingart, Karen R.; Pai, Madhukar; Denkinger, Claudia M.

2017-01-01

Only 25% of multidrug-resistant tuberculosis (MDR-TB) cases are currently diagnosed. Line probe assays (LPAs) enable rapid drug-susceptibility testing for rifampicin (RIF) and isoniazid (INH) resistance and Mycobacterium tuberculosis detection. Genotype MTBDRplusV1 was WHO-endorsed in 2008 but newer LPAs have since been developed. This systematic review evaluated three LPAs: Hain Genotype MTBDRplusV1, MTBDRplusV2 and Nipro NTM+MDRTB. Study quality was assessed with QUADAS-2. Bivariate random-effects meta-analyses were performed for direct and indirect testing. Results for RIF and INH resistance were compared to phenotypic and composite (incorporating sequencing) reference standards. M. tuberculosis detection results were compared to culture. 74 unique studies were included. For RIF resistance (21 225 samples), pooled sensitivity and specificity (with 95% confidence intervals) were 96.7% (95.6–97.5%) and 98.8% (98.2–99.2%). For INH resistance (20 954 samples), pooled sensitivity and specificity were 90.2% (88.2–91.9%) and 99.2% (98.7–99.5%). Results were similar for direct and indirect testing and across LPAs. Using a composite reference standard, specificity increased marginally. For M. tuberculosis detection (3451 samples), pooled sensitivity was 94% (89.4–99.4%) for smear-positive specimens and 44% (20.2–71.7%) for smear-negative specimens. In patients with pulmonary TB, LPAs have high sensitivity and specificity for RIF resistance and high specificity and good sensitivity for INH resistance. This meta-analysis provides evidence for policy and practice. PMID:28100546

Performance of the ASAS classification criteria for axial and peripheral spondyloarthritis: a systematic literature review and meta-analysis.

PubMed

Sepriano, Alexandre; Rubio, Roxana; Ramiro, Sofia; Landewé, Robert; van der Heijde, Désirée

2017-05-01

To summarise the evidence on the performance of the Assessment of SpondyloArthritis international Society (ASAS) classification criteria for axial spondyloarthritis (axSpA) (also imaging and clinical arm separately), peripheral (p)SpA and the entire set, when tested against the rheumatologist's diagnosis ('reference standard'). A systematic literature review was performed to identify eligible studies. Raw data on SpA diagnosis and classification were extracted or, if necessary, obtained from the authors of the selected publications. A meta-analysis was performed to obtain pooled estimates for sensitivity, specificity, positive and negative likelihood ratios, by fitting random effects models. Nine papers fulfilled the inclusion criteria (N=5739 patients). The entire set of the ASAS SpA criteria yielded a high pooled sensitivity (73%) and specificity (88%). Similarly, good results were found for the axSpA criteria (sensitivity: 82%; specificity: 88%). Splitting the axSpA criteria in 'imaging arm only' and 'clinical arm only' resulted in much lower sensitivity (30% and 23% respectively), but very high specificity was retained (97% and 94% respectively). The pSpA criteria were less often tested than the axSpA criteria and showed a similarly high pooled specificity (87%) but lower sensitivity (63%). Accumulated evidence from studies with more than 5500 patients confirms the good performance of the various ASAS SpA criteria as tested against the rheumatologist's diagnosis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Analysis of the sensitivity properties of a model of vector-borne bubonic plague.

PubMed

Buzby, Megan; Neckels, David; Antolin, Michael F; Estep, Donald

2008-09-06

Model sensitivity is a key to evaluation of mathematical models in ecology and evolution, especially in complex models with numerous parameters. In this paper, we use some recently developed methods for sensitivity analysis to study the parameter sensitivity of a model of vector-borne bubonic plague in a rodent population proposed by Keeling & Gilligan. The new sensitivity tools are based on a variational analysis involving the adjoint equation. The new approach provides a relatively inexpensive way to obtain derivative information about model output with respect to parameters. We use this approach to determine the sensitivity of a quantity of interest (the force of infection from rats and their fleas to humans) to various model parameters, determine a region over which linearization at a specific parameter reference point is valid, develop a global picture of the output surface, and search for maxima and minima in a given region in the parameter space.

Differential Lipid Profiles of Normal Human Brain Matter and Gliomas by Positive and Negative Mode Desorption Electrospray Ionization – Mass Spectrometry Imaging

PubMed Central

Pirro, Valentina; Hattab, Eyas M.; Cohen-Gadol, Aaron A.; Cooks, R. Graham

2016-01-01

Desorption electrospray ionization—mass spectrometry (DESI-MS) imaging was used to analyze unmodified human brain tissue sections from 39 subjects sequentially in the positive and negative ionization modes. Acquisition of both MS polarities allowed more complete analysis of the human brain tumor lipidome as some phospholipids ionize preferentially in the positive and others in the negative ion mode. Normal brain parenchyma, comprised of grey matter and white matter, was differentiated from glioma using positive and negative ion mode DESI-MS lipid profiles with the aid of principal component analysis along with linear discriminant analysis. Principal component–linear discriminant analyses of the positive mode lipid profiles was able to distinguish grey matter, white matter, and glioma with an average sensitivity of 93.2% and specificity of 96.6%, while the negative mode lipid profiles had an average sensitivity of 94.1% and specificity of 97.4%. The positive and negative mode lipid profiles provided complementary information. Principal component–linear discriminant analysis of the combined positive and negative mode lipid profiles, via data fusion, resulted in approximately the same average sensitivity (94.7%) and specificity (97.6%) of the positive and negative modes when used individually. However, they complemented each other by improving the sensitivity and specificity of all classes (grey matter, white matter, and glioma) beyond 90% when used in combination. Further principal component analysis using the fused data resulted in the subgrouping of glioma into two groups associated with grey and white matter, respectively, a separation not apparent in the principal component analysis scores plots of the separate positive and negative mode data. The interrelationship of tumor cell percentage and the lipid profiles is discussed, and how such a measure could be used to measure residual tumor at surgical margins. PMID:27658243

Diagnostic value of secreted frizzled-related protein 2 gene promoter hypermethylation in stool for colorectal cancer: A meta-analysis.

PubMed

Zhou, Zhiran; Zhang, Huitian; Lei, Yunxia

2016-10-01

To evaluate the diagnostic value of secreted frizzled-related protein 2 (SFRP2) gene promoter hypermethylation in stool for colorectal cancer (CRC). Open published diagnostic study of SFRP2 gene promoter hypermethylation in stool for CRC detection was electronic searched in the databases of PubMed, EMBASE, Cochrane Library, Web of Science, and China National Knowledge Infrastructure. The data of true positive, false positive false negative, and true negative identified by stool SFRP2 gene hypermethylation was extracted and pooled for diagnostic sensitivity, specificity, and summary receiver operating characteristic (SROC) curve. According to the inclusion and exclusion criteria, we finally included nine publications with 792 cases in the meta-analysis. Thus, the diagnostic sensitivity was aggregated through random effect model. The pooled sensitivity was 0.82 with the corresponding 95% confidence interval (95% CI) of 0.79-0.85; the pooled specificity and its corresponding 95% CI were 0.47 and 0.40-0.53 by the random effect model; we pooled the SROC curve by sensitivity versus specificity according to data published in the nine studies. The area under the SROC curve was 0.70 (95% CI: 0.65-0.73). SFRP2 gene promoter hypermethylation in stool can was a potential biomarker for CRC diagnosis with relative high sensitivity.

[Health economics analysis of specific immunotherapy in allergic rhinitis accompanied with asthma].

PubMed

Chen, Jianjun; Xiang, Jisheng; Wang, Yanjun; Shi, Qiumei; Tan, Huifang; Kong, Weijia

2013-09-01

To investigate the cost-effectiveness of standardized specific immunotherapy (SIT) for allergic rhinitis patients accompanied with asthma (ARAS) in China. Forty ARAS patients sensitized with house dust mite (HDM) were administered with SIT (SIT group) or merely medicine treatment (control group). Alutard dermatophagoides pteronyssinus vaccine from ALK company was used for immunotherapy. The usage of symptom control medicine was according to the ARIA and GINA guideline. Cost-effectiveness ratio (CER) and Incremental cost-effectiveness ratio(ICER) analysis was conducted. The effectiveness was measured in terms of symptom scores, quality of life, objective improvement of rhinitis and asthma. Sensitive analysis was conducted to verify the stability of the results. The cost of SIT group for 1 year (6578 yuan) was higher than that of control group (1733.3 yuan), while the cost-effectiveness ratio and incremental cost-effectiveness ratio of SIT group were significant better than that of control group in all items. CER was 1686.7 yuan in SIT group compared with 3466.6 yuan in control group for nasal symptom scores, 4698.6 yuan in SIT group compared with 5777.8 yuan in control group for asthma symptom scores, 3462.1 yuan in SIT group compared with 8666.7 yuan in control group. The sensitive analysis of the price 10 percent higher or lower showed the same results. The cost-effectiveness of specific immunotherapy (SIT) for mite sensitized ARAS patients was better than that of merely medicine treatment.

[Implication of inverse-probability weighting method in the evaluation of diagnostic test with verification bias].

PubMed

Kang, Leni; Zhang, Shaokai; Zhao, Fanghui; Qiao, Youlin

2014-03-01

To evaluate and adjust the verification bias existed in the screening or diagnostic tests. Inverse-probability weighting method was used to adjust the sensitivity and specificity of the diagnostic tests, with an example of cervical cancer screening used to introduce the Compare Tests package in R software which could be implemented. Sensitivity and specificity calculated from the traditional method and maximum likelihood estimation method were compared to the results from Inverse-probability weighting method in the random-sampled example. The true sensitivity and specificity of the HPV self-sampling test were 83.53% (95%CI:74.23-89.93)and 85.86% (95%CI: 84.23-87.36). In the analysis of data with randomly missing verification by gold standard, the sensitivity and specificity calculated by traditional method were 90.48% (95%CI:80.74-95.56)and 71.96% (95%CI:68.71-75.00), respectively. The adjusted sensitivity and specificity under the use of Inverse-probability weighting method were 82.25% (95% CI:63.11-92.62) and 85.80% (95% CI: 85.09-86.47), respectively, whereas they were 80.13% (95%CI:66.81-93.46)and 85.80% (95%CI: 84.20-87.41) under the maximum likelihood estimation method. The inverse-probability weighting method could effectively adjust the sensitivity and specificity of a diagnostic test when verification bias existed, especially when complex sampling appeared.

Accuracy of i-Scan for Optical Diagnosis of Colonic Polyps: A Meta-Analysis

PubMed Central

Guo, Chuan-Guo; Ji, Rui; Li, Yan-Qing

2015-01-01

Background i-Scan is a novel virtual chromoendoscopy system designed to enhance surface and vascular patterns to improve optical diagnostic performance. Numerous prospective studies have been done to evaluate the accuracy of i-Scan in differentiating colonic neoplasms from non-neoplasms. i-Scan could be an effective endoscopic technique for optical diagnosis of colonic polyps. Objective Our aim of this study was to perform a meta-analysis of published data to establish the diagnostic accuracy of i-Scan for optical diagnosis of colonic polyps. Methods We searched PubMed, Medline, Elsevier ScienceDirect and Cochrane Library databases. We used a bivariate meta-analysis following a random effects model to summarize the data and plotted hierarchical summary receiver-operating characteristic (HSROC) curves. The area under the HSROC curve (AUC) serves as an indicator of the diagnostic accuracy. Results The meta-analysis included a total of 925 patients and 2312 polyps. For the overall studies, the area under the HSROC curve was 0.96. The summary sensitivity was 90.4% (95%CI 85%-94.1%) and specificity was 90.9% (95%CI 84.3%-94.9%). In 11 studies predicting polyps histology in real-time, the summary sensitivity and specificity was 91.5% (95%CI 85.7%-95.1%) and 92.1% (95%CI 84.5%-96.1%), respectively, with the AUC of 0.97. For three different diagnostic criteria (Kudo, NICE, others), the sensitivity was 86.3%, 93.0%, 85.0%, respectively and specificity was 84.8%, 94.4%, 91.8%, respectively. Conclusions Endoscopic diagnosis with i-Scan has accurate optical diagnostic performance to differentiate neoplastic from non-neoplastic polyps with an area under the HSROC curve exceeding 0.90. Both the sensitivity and specificity for diagnosing colonic polyps are over 90%. PMID:25978459

Relationship between Grooming Performance and Motor and Cognitive Functions in Stroke Patients with Receiver Operating Characteristic Analysis.

PubMed

Fujita, Takaaki; Sato, Atsushi; Tsuchiya, Kenji; Ohashi, Takuro; Yamane, Kazuhiro; Yamamoto, Yuichi; Iokawa, Kazuaki; Ohira, Yoko; Otsuki, Koji; Tozato, Fusae

2017-12-01

This study aimed to elucidate the relationship between grooming performance of stroke patients and various motor and cognitive functions and to examine the cognitive and physical functional standards required for grooming independence. We retrospectively analyzed the data of 96 hospitalized patients with first stroke in a rehabilitation hospital ward. Logistic regression analysis and receiver operating characteristic curves were used to investigate the related cognitive and motor functions with grooming performance and to calculate the cutoff values for independence and supervision levels in grooming. For analysis between the independent and supervision-dependent groups, the only item with an area under the curve (AUC) of .9 or higher was the Berg Balance Scale, and the calculated cutoff value was 41/40 (sensitivity, 83.6%; specificity, 87.8%). For analysis between the independent-supervision and dependent groups, the items with an AUC of .9 or higher were the Simple Test for Evaluating Hand Function (STEF) on the nonaffected side, Vitality Index (VI), and FIM ® cognition. The cutoff values were 68/67 for the STEF (sensitivity, 100%; specificity, 72.2%), 9/8 points for the VI (sensitivity, 92.3%; specificity, 88.9%), and 23/22 points for FIM ® cognition (sensitivity, 91.0%; specificity, 88.9%). Our results suggest that upper-extremity functions on the nonaffected side, motivation, and cognitive functions are particularly important to achieve the supervision level and that balance is important to reach the independence level. The effective improvement of grooming performance is possible by performing therapeutic or compensatory intervention on functions that have not achieved these cutoff values. Copyright © 2017 National Stroke Association. Published by Elsevier Inc. All rights reserved.

Detection of cervical lesions by multivariate analysis of diffuse reflectance spectra: a clinical study.

PubMed

Prabitha, Vasumathi Gopala; Suchetha, Sambasivan; Jayanthi, Jayaraj Lalitha; Baiju, Kamalasanan Vijayakumary; Rema, Prabhakaran; Anuraj, Koyippurath; Mathews, Anita; Sebastian, Paul; Subhash, Narayanan

2016-01-01

Diffuse reflectance (DR) spectroscopy is a non-invasive, real-time, and cost-effective tool for early detection of malignant changes in squamous epithelial tissues. The present study aims to evaluate the diagnostic power of diffuse reflectance spectroscopy for non-invasive discrimination of cervical lesions in vivo. A clinical trial was carried out on 48 sites in 34 patients by recording DR spectra using a point-monitoring device with white light illumination. The acquired data were analyzed and classified using multivariate statistical analysis based on principal component analysis (PCA) and linear discriminant analysis (LDA). Diagnostic accuracies were validated using random number generators. The receiver operating characteristic (ROC) curves were plotted for evaluating the discriminating power of the proposed statistical technique. An algorithm was developed and used to classify non-diseased (normal) from diseased sites (abnormal) with a sensitivity of 72 % and specificity of 87 %. While low-grade squamous intraepithelial lesion (LSIL) could be discriminated from normal with a sensitivity of 56 % and specificity of 80 %, and high-grade squamous intraepithelial lesion (HSIL) from normal with a sensitivity of 89 % and specificity of 97 %, LSIL could be discriminated from HSIL with 100 % sensitivity and specificity. The areas under the ROC curves were 0.993 (95 % confidence interval (CI) 0.0 to 1) and 1 (95 % CI 1) for the discrimination of HSIL from normal and HSIL from LSIL, respectively. The results of the study show that DR spectroscopy could be used along with multivariate analytical techniques as a non-invasive technique to monitor cervical disease status in real time.

Tumor invasiveness defined by IASLC/ATS/ERS classification of ground-glass nodules can be predicted by quantitative CT parameters.

PubMed

Zhou, Qian-Jun; Zheng, Zhi-Chun; Zhu, Yong-Qiao; Lu, Pei-Ji; Huang, Jia; Ye, Jian-Ding; Zhang, Jie; Lu, Shun; Luo, Qing-Quan

2017-05-01

To investigate the potential value of CT parameters to differentiate ground-glass nodules between noninvasive adenocarcinoma and invasive pulmonary adenocarcinoma (IPA) as defined by IASLC/ATS/ERS classification. We retrospectively reviewed 211 patients with pathologically proved stage 0-IA lung adenocarcinoma which appeared as subsolid nodules, from January 2012 to January 2013 including 137 pure ground glass nodules (pGGNs) and 74 part-solid nodules (PSNs). Pathological data was classified under the 2011 IASLC/ATS/ERS classification. Both quantitative and qualitative CT parameters were used to determine the tumor invasiveness between noninvasive adenocarcinomas and IPAs. There were 154 noninvasive adenocarcinomas and 57 IPAs. In pGGNs, CT size and area, one-dimensional mean CT value and bubble lucency were significantly different between noninvasive adenocarcinomas and IPAs on univariate analysis. Multivariate regression and ROC analysis revealed that CT size and one-dimensional mean CT value were predictive of noninvasive adenocarcinomas compared to IPAs. Optimal cutoff value was 13.60 mm (sensitivity, 75.0%; specificity, 99.6%), and -583.60 HU (sensitivity, 68.8%; specificity, 66.9%). In PSNs, there were significant differences in CT size and area, solid component area, solid proportion, one-dimensional mean and maximum CT value, three-dimensional (3D) mean CT value between noninvasive adenocarcinomas and IPAs on univariate analysis. Multivariate and ROC analysis showed that CT size and 3D mean CT value were significantly differentiators. Optimal cutoff value was 19.64 mm (sensitivity, 53.7%; specificity, 93.9%), -571.63 HU (sensitivity, 85.4%; specificity, 75.8%). For pGGNs, CT size and one-dimensional mean CT value are determinants for tumor invasiveness. For PSNs, tumor invasiveness can be predicted by CT size and 3D mean CT value.

Sensitivity and Specificity of Polysomnographic Criteria for Defining Insomnia

PubMed Central

Edinger, Jack D.; Ulmer, Christi S.; Means, Melanie K.

2013-01-01

Study Objectives: In recent years, polysomnography-based eligibility criteria have been increasingly used to identify candidates for insomnia research, and this has been particularly true of studies evaluating pharmacologic therapy for primary insomnia. However, the sensitivity and specificity of PSG for identifying individuals with insomnia is unknown, and there is no consensus on the criteria sets which should be used for participant selection. In the current study, an archival data set was used to test the sensitivity and specificity of PSG measures for identifying individuals with primary insomnia in both home and lab settings. We then evaluated the sensitivity and specificity of the eligibility criteria employed in a number of recent insomnia trials for identifying primary insomnia sufferers in our sample. Design: Archival data analysis. Settings: Study participants' homes and a clinical sleep laboratory. Participants: Adults: 76 with primary insomnia and 78 non-complaining normal sleepers. Measurements and Results: ROC and cross-tabs analyses were used to evaluate the sensitivity and specificity of PSG-derived total sleep time, latency to persistent sleep, wake after sleep onset, and sleep efficiency for discriminating adults with primary insomnia from normal sleepers. None of the individual criteria accurately discriminated PI from normal sleepers, and none of the criteria sets used in recent trials demonstrated acceptable sensitivity and specificity for identifying primary insomnia. Conclusions: The use of quantitative PSG-based selection criteria in insomnia research may exclude many who meet current diagnostic criteria for an insomnia disorder. Citation: Edinger JD; Ulmer CS; Means MK. Sensitivity and specificity of polysomnographic criteria for defining insomnia. J Clin Sleep Med 2013;9(5):481-491. PMID:23674940

Sensitivity and specificity of noncontrast magnetic resonance imaging reports in the diagnosis of type-II superior labral anterior-posterior lesions in the community setting.

PubMed

Connolly, Keith P; Schwartzberg, Randy S; Reuss, Bryan; Crumbie, David; Homan, Brad M

2013-02-20

Magnetic resonance imaging (MRI) has been suggested to be of high accuracy at academic institutions in the identification of superior labral tears; however, many Type-II superior labral anterior-posterior (SLAP) lesions encountered during arthroscopy have not been previously diagnosed with noncontrast images. This study evaluated the accuracy of diagnosing Type-II SLAP lesions in a community setting with use of noncontrast MRI and analyzed the effect that radiologist training and the scanner type or magnet strength had on sensitivity and specificity. One hundred and forty-four patients requiring repair of an arthroscopically confirmed Type-II SLAP lesion who had a noncontrast MRI examination performed within twelve months before the procedure were included in the sensitivity analysis. An additional 100 patients with arthroscopically confirmed, normal superior labral anatomy were identified for specificity analysis. The transcribed interpretations of the images by the radiologists were used to document the diagnosis of a SLAP lesion and were compared with the operative report. The magnet strength, type of MRI system (open or closed), and whether the radiologist had completed a musculoskeletal fellowship were also recorded. Noncontrast MRI identified SLAP lesions in fifty-four of 144 shoulders, yielding an overall sensitivity of 38% (95% confidence interval [CI] = 30%, 46%). Specificity was 94% (95% CI = 87%, 98%), with six SLAP lesions diagnosed in 100 shoulders that did not contain the lesion. Musculoskeletal fellowship-trained radiologists performed with higher sensitivity than those who had not completed the fellowship (46% versus 19%; p = 0.009). Our results demonstrate a low sensitivity and high specificity in the diagnosis of Type-II SLAP lesions with noncontrast MRI in this community setting. Musculoskeletal fellowship-trained radiologists had significantly higher sensitivities in accurately diagnosing the lesion than did radiologists without such training. Noncontrast MRI is not a reliable diagnostic tool for Type-II SLAP lesions in a community setting.

Chronic pesticide poisoning from persistent low-dose exposures in Ecuadorean floriculture workers: toward validating a low-cost test battery.

PubMed

Breilh, Jaime; Pagliccia, Nino; Yassi, Annalee

2012-01-01

Chronic pesticide poisoning is difficult to detect. We sought to develop a low-cost test battery for settings such as Ecuador's floriculture industry. First we had to develop a case definition; as with all occupational diseases a case had to have both sufficient effective dose and associated health effects. For the former, using canonical discriminant analysis, we found that adding measures of protection and overall environmental stressors to occupational category and duration of exposure was useful. For the latter, factor analysis suggested three distinct manifestations of pesticide poisoning. We then determined sensitivity and specificity of various combinations of symptoms and simple neurotoxicity tests from the Pentox questionnaire, and found that doing so increased sensitivity and specificity compared to use of acethylcholinesterase alone--the current screening standard. While sensitivity and specificity varied with different case definitions, our results support the development of a low-cost test battery for screening in such settings.

Analysis of world terror networks from the reduced Google matrix of Wikipedia

NASA Astrophysics Data System (ADS)

El Zant, Samer; Frahm, Klaus M.; Jaffrès-Runser, Katia; Shepelyansky, Dima L.

2018-01-01

We apply the reduced Google matrix method to analyze interactions between 95 terrorist groups and determine their relationships and influence on 64 world countries. This is done on the basis of the Google matrix of the English Wikipedia (2017) composed of 5 416 537 articles which accumulate a great part of global human knowledge. The reduced Google matrix takes into account the direct and hidden links between a selection of 159 nodes (articles) appearing due to all paths of a random surfer moving over the whole network. As a result we obtain the network structure of terrorist groups and their relations with selected countries including hidden indirect links. Using the sensitivity of PageRank to a weight variation of specific links we determine the geopolitical sensitivity and influence of specific terrorist groups on world countries. The world maps of the sensitivity of various countries to influence of specific terrorist groups are obtained. We argue that this approach can find useful application for more extensive and detailed data bases analysis.

Analysis of Publically Available Skin Sensitization Data from REACH Registrations 2008–2014

PubMed Central

Luechtefeld, Thomas; Maertens, Alexandra; Russo, Daniel P.; Rovida, Costanza; Zhu, Hao; Hartung, Thomas

2017-01-01

Summary The public data on skin sensitization from REACH registrations already included 19,111 studies on skin sensitization in December 2014, making it the largest repository of such data so far (1,470 substances with mouse LLNA, 2,787 with GPMT, 762 with both in vivo and in vitro and 139 with only in vitro data). 21% were classified as sensitizers. The extracted skin sensitization data was analyzed to identify relationships in skin sensitization guidelines, visualize structural relationships of sensitizers, and build models to predict sensitization. A chemical with molecular weight > 500 Da is generally considered non-sensitizing owing to low bioavailability, but 49 sensitizing chemicals with a molecular weight > 500 Da were found. A chemical similarity map was produced using PubChem’s 2D Tanimoto similarity metric and Gephi force layout visualization. Nine clusters of chemicals were identified by Blondel’s module recognition algorithm revealing wide module-dependent variation. Approximately 31% of mapped chemicals are Michael’s acceptors but alone this does not imply skin sensitization. A simple sensitization model using molecular weight and five ToxTree structural alerts showed a balanced accuracy of 65.8% (specificity 80.4%, sensitivity 51.4%), demonstrating that structural alerts have information value. A simple variant of k-nearest neighbors outperformed the ToxTree approach even at 75% similarity threshold (82% balanced accuracy at 0.95 threshold). At higher thresholds, the balanced accuracy increased. Lower similarity thresholds decrease sensitivity faster than specificity. This analysis scopes the landscape of chemical skin sensitization, demonstrating the value of large public datasets for health hazard prediction. PMID:26863411

Automated analysis of retinal images for detection of referable diabetic retinopathy.

PubMed

Abràmoff, Michael D; Folk, James C; Han, Dennis P; Walker, Jonathan D; Williams, David F; Russell, Stephen R; Massin, Pascale; Cochener, Beatrice; Gain, Philippe; Tang, Li; Lamard, Mathieu; Moga, Daniela C; Quellec, Gwénolé; Niemeijer, Meindert

2013-03-01

The diagnostic accuracy of computer detection programs has been reported to be comparable to that of specialists and expert readers, but no computer detection programs have been validated in an independent cohort using an internationally recognized diabetic retinopathy (DR) standard. To determine the sensitivity and specificity of the Iowa Detection Program (IDP) to detect referable diabetic retinopathy (RDR). In primary care DR clinics in France, from January 1, 2005, through December 31, 2010, patients were photographed consecutively, and retinal color images were graded for retinopathy severity according to the International Clinical Diabetic Retinopathy scale and macular edema by 3 masked independent retinal specialists and regraded with adjudication until consensus. The IDP analyzed the same images at a predetermined and fixed set point. We defined RDR as more than mild nonproliferative retinopathy and/or macular edema. A total of 874 people with diabetes at risk for DR. Sensitivity and specificity of the IDP to detect RDR, area under the receiver operating characteristic curve, sensitivity and specificity of the retinal specialists' readings, and mean interobserver difference (κ). The RDR prevalence was 21.7% (95% CI, 19.0%-24.5%). The IDP sensitivity was 96.8% (95% CI, 94.4%-99.3%) and specificity was 59.4% (95% CI, 55.7%-63.0%), corresponding to 6 of 874 false-negative results (none met treatment criteria). The area under the receiver operating characteristic curve was 0.937 (95% CI, 0.916-0.959). Before adjudication and consensus, the sensitivity/specificity of the retinal specialists were 0.80/0.98, 0.71/1.00, and 0.91/0.95, and the mean intergrader κ was 0.822. The IDP has high sensitivity and specificity to detect RDR. Computer analysis of retinal photographs for DR and automated detection of RDR can be implemented safely into the DR screening pipeline, potentially improving access to screening and health care productivity and reducing visual loss through early treatment.

Differentiation between diverticulitis and colorectal cancer: quantitative CT perfusion measurements versus morphologic criteria--initial experience.

PubMed

Goh, Vicky; Halligan, Steve; Taylor, Stuart A; Burling, David; Bassett, Paul; Bartram, Clive I

2007-02-01

To determine whether computed tomographic (CT) perfusion measurements in prospectively recruited patients can be used to differentiate between diverticulitis and colorectal cancer and to compare this discrimination with that of standard morphologic criteria. After institutional review board approval and written informed consent were obtained, 60 patients (24 men, 36 women; mean age, 69 years; range, 33.5-90.4 years; 20 patients with cancer, 20 with diverticulitis, and 20 with inactive diverticular disease) underwent CT perfusion imaging at the level of the colonic abnormality, and perfusion parameters were calculated. Analysis of variance was used to investigate any differences in perfusion between the patient groups. Two independent observers also analyzed an abdominopelvic CT study obtained immediately after the CT perfusion study and noted standard morphologic criteria for differential diagnosis. The sensitivity and specificity of CT perfusion measurements for determining the diagnostic category were compared with morphologic criteria by means of multivariate analysis to identify the most discriminatory criteria. Mean blood volume, blood flow, transit time, and permeability were significantly different between patients with cancer and those with diverticulitis (P < .0001); patients with cancer had the highest blood volume, blood flow, and permeability and the shortest transit time. The most discriminatory criteria for determining diagnostic category were blood volume, transit time, permeability, and presence of pericolonic nodes (P = .05, .02, .04, and .02, respectively). Blood volume and blood flow each had a sensitivity of 80% and had specificity of 70% and 75%, respectively, for cancer in comparison with standard morphologic criteria: less than 5 cm of bowel involvement (45% sensitivity, 95% specificity), presence of a mass (85% sensitivity, 90% specificity), pericolonic inflammation (75% sensitivity, 5% specificity), and pericolonic nodes (90% sensitivity, 45% specificity). CT perfusion measurements enable differentiation and better discrimination, in comparison with morphologic criteria, between cancer and diverticulitis. (c) RSNA, 2007.

Enabling Predictive Simulation and UQ of Complex Multiphysics PDE Systems by the Development of Goal-Oriented Variational Sensitivity Analysis and a-Posteriori Error Estimation Methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Estep, Donald

2015-11-30

This project addressed the challenge of predictive computational analysis of strongly coupled, highly nonlinear multiphysics systems characterized by multiple physical phenomena that span a large range of length- and time-scales. Specifically, the project was focused on computational estimation of numerical error and sensitivity analysis of computational solutions with respect to variations in parameters and data. In addition, the project investigated the use of accurate computational estimates to guide efficient adaptive discretization. The project developed, analyzed and evaluated new variational adjoint-based techniques for integration, model, and data error estimation/control and sensitivity analysis, in evolutionary multiphysics multiscale simulations.

Sensitivity analysis of a sound absorption model with correlated inputs

NASA Astrophysics Data System (ADS)

Chai, W.; Christen, J.-L.; Zine, A.-M.; Ichchou, M.

2017-04-01

Sound absorption in porous media is a complex phenomenon, which is usually addressed with homogenized models, depending on macroscopic parameters. Since these parameters emerge from the structure at microscopic scale, they may be correlated. This paper deals with sensitivity analysis methods of a sound absorption model with correlated inputs. Specifically, the Johnson-Champoux-Allard model (JCA) is chosen as the objective model with correlation effects generated by a secondary micro-macro semi-empirical model. To deal with this case, a relatively new sensitivity analysis method Fourier Amplitude Sensitivity Test with Correlation design (FASTC), based on Iman's transform, is taken into application. This method requires a priori information such as variables' marginal distribution functions and their correlation matrix. The results are compared to the Correlation Ratio Method (CRM) for reference and validation. The distribution of the macroscopic variables arising from the microstructure, as well as their correlation matrix are studied. Finally the results of tests shows that the correlation has a very important impact on the results of sensitivity analysis. Assessment of correlation strength among input variables on the sensitivity analysis is also achieved.

Value of high-sensitivity C-reactive protein assays in predicting atrial fibrillation recurrence: a systematic review and meta-analysis

PubMed Central

Yo, Chia-Hung; Lee, Si-Huei; Chang, Shy-Shin; Lee, Matthew Chien-Hung; Lee, Chien-Chang

2014-01-01

Objectives We performed a systematic review and meta-analysis of studies on high-sensitivity C-reactive protein (hs-CRP) assays to see whether these tests are predictive of atrial fibrillation (AF) recurrence after cardioversion. Design Systematic review and meta-analysis. Data sources PubMed, EMBASE and Cochrane databases as well as a hand search of the reference lists in the retrieved articles from inception to December 2013. Study eligibility criteria This review selected observational studies in which the measurements of serum CRP were used to predict AF recurrence. An hs-CRP assay was defined as any CRP test capable of measuring serum CRP to below 0.6 mg/dL. Primary and secondary outcome measures We summarised test performance characteristics with the use of forest plots, hierarchical summary receiver operating characteristic curves and bivariate random effects models. Meta-regression analysis was performed to explore the source of heterogeneity. Results We included nine qualifying studies comprising a total of 347 patients with AF recurrence and 335 controls. A CRP level higher than the optimal cut-off point was an independent predictor of AF recurrence after cardioversion (summary adjusted OR: 3.33; 95% CI 2.10 to 5.28). The estimated pooled sensitivity and specificity for hs-CRP was 71.0% (95% CI 63% to 78%) and 72.0% (61% to 81%), respectively. Most studies used a CRP cut-off point of 1.9 mg/L to predict long-term AF recurrence (77% sensitivity, 65% specificity), and 3 mg/L to predict short-term AF recurrence (73% sensitivity, 71% specificity). Conclusions hs-CRP assays are moderately accurate in predicting AF recurrence after successful cardioversion. PMID:24556243

The Credibility Revolution in Empirical Economics: How Better Research Design is Taking the Con out of Econometrics. NBER Working Paper No. 15794

ERIC Educational Resources Information Center

Angrist, Joshua; Pischke, Jorn-Steffen

2010-01-01

This essay reviews progress in empirical economics since Leamer'rs (1983) critique. Leamer highlighted the benefits of sensitivity analysis, a procedure in which researchers show how their results change with changes in specification or functional form. Sensitivity analysis has had a salutary but not a revolutionary effect on econometric practice.…

Diagnostic performance of FDG PET or PET/CT in prosthetic infection after arthroplasty: a meta-analysis.

PubMed

Jin, H; Yuan, L; Li, C; Kan, Y; Hao, R; Yang, J

2014-03-01

The purpose of this study was to systematically review and perform a meta-analysis of published data regarding the diagnostic performance of positron emission tomography (PET) or PET/computed tomography (PET/CT) in prosthetic infection after arthroplasty. A comprehensive computer literature search of studies published through May 31, 2012 regarding PET or PET/CT in patients suspicious of prosthetic infection was performed in PubMed/MEDLINE, Embase and Scopus databases. Pooled sensitivity and specificity of PET or PET/CT in patients suspicious of prosthetic infection on a per prosthesis-based analysis were calculated. The area under the receiver-operating characteristic (ROC) curve was calculated to measure the accuracy of PET or PET/CT in patients with suspicious of prosthetic infection. Fourteen studies comprising 838 prosthesis with suspicious of prosthetic infection after arthroplasty were included in this meta-analysis. The pooled sensitivity of PET or PET/CT in detecting prosthetic infection was 86% (95% confidence interval [CI] 82-90%) on a per prosthesis-based analysis. The pooled specificity of PET or PET/CT in detecting prosthetic infection was 86% (95% CI 83-89%) on a per prosthesis-based analysis. The area under the ROC curve was 0.93 on a per prosthesis-based analysis. In patients suspicious of prosthetic infection, FDG PET or PET/CT demonstrated high sensitivity and specificity. FDG PET or PET/CT are accurate methods in this setting. Nevertheless, possible sources of false positive results and influcing factors should kept in mind.

A meta-analysis of confocal laser endomicroscopy for the detection of neoplasia in patients with Barrett's esophagus.

PubMed

Xiong, Yi-Quan; Ma, Shu-Juan; Zhou, Jun-Hua; Zhong, Xue-Shan; Chen, Qing

2016-06-01

Barrett's esophagus (BE) is considered the most important risk factor for development of esophageal adenocarcinoma. Confocal laser endomicroscopy (CLE) is a recently developed technique used to diagnose neoplasia in BE. This meta-analysis was performed to assess the accuracy of CLE for diagnosis of neoplasia in BE. We searched EMBASE, PubMed, Cochrane Library, and Web of Science to identify relevant studies for all articles published up to June 27, 2015 in English. The quality of included studies was assessed using QUADAS-2. Per-patient and per-lesion pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio with 95% confidence intervals (CIs) were calculated. In total, 14 studies were included in the final analysis, covering 789 patients with 4047 lesions. Seven studies were included in the per-patient analysis. Pooled sensitivity and specificity were 89% (95% CI: 0.82-0.94) and 83% (95% CI: 0.78-0.86), respectively. Ten studies were included in the per-lesion analysis. Compared with the PP analysis, the corresponding pooled sensitivity declined to 77% (95% CI: 0.73-0.81) and specificity increased to 89% (95% CI: 0.87-0.90). Subgroup analysis showed that probe-based CLE (pCLE) was superior to endoscope-based CLE (eCLE) in pooled specificity [91.4% (95% CI: 89.7-92.9) vs 86.1% (95% CI: 84.3-87.8)] and AUC for the sROC (0.885 vs 0.762). Confocal laser endomicroscopy is a valid method to accurately differentiate neoplasms from non-neoplasms in BE. It can be applied to BE surveillance and early diagnosis of esophageal adenocarcinoma. © 2015 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

Immunodetection of the Bacteriocin Lacticin RM: Analysis of the Influence of Temperature and Tween 80 on Its Expression and Activity

PubMed Central

Keren, Tomer; Yarmus, Merav; Halevy, Galia; Shapira, Roni

2004-01-01

Immunoassays with specific antibodies offer higher sensitivity than do bioassays with indicator strains in the detection and quantification of several bacteriocins. Here we present the purification of lacticin RM and the production of specific polyclonal antibodies to a synthetic peptide resembling an internal fragment of the mature bacteriocin. The specificity and sensitivity of the generated polyclonal antibodies were evaluated in various immunoassays. The detection limits of lacticin RM were found to be 1.9, 0.16, and 0.18 μg ml−1 for Western blot, immuno-dot blot, and noncompetitive indirect enzyme-linked immunosorbent assays, respectively. Immunoassay sensitivities were 12.5-fold higher than that of the agar diffusion test (ADT). The production of lacticin RM showed temperature dependency, with 3, 4.2, 12.7, 28.9, 37.8, and 12 μg ml−1 at 37, 30, 20, 15, 10, and 4°C, respectively. Temperature-stability analysis demonstrated that lacticin RM is sensitive to mild temperature, but the loss of activity does not seem to result from protein degradation. Tween 80 increased the concentration of lacticin RM eightfold and probably affected the results of the ADT either by enhancing the activity of lacticin RM or by increasing the sensitivity of the indicator strain. The use of antibodies for the specific detection and quantification of lacticin RM can expand our knowledge of its production and stability, with important implications for further investigation and future application. PMID:15066801

Evaluation and construction of diagnostic criteria for inclusion body myositis

PubMed Central

Mammen, Andrew L.; Amato, Anthony A.; Weiss, Michael D.; Needham, Merrilee

2014-01-01

Objective: To use patient data to evaluate and construct diagnostic criteria for inclusion body myositis (IBM), a progressive disease of skeletal muscle. Methods: The literature was reviewed to identify all previously proposed IBM diagnostic criteria. These criteria were applied through medical records review to 200 patients diagnosed as having IBM and 171 patients diagnosed as having a muscle disease other than IBM by neuromuscular specialists at 2 institutions, and to a validating set of 66 additional patients with IBM from 2 other institutions. Machine learning techniques were used for unbiased construction of diagnostic criteria. Results: Twenty-four previously proposed IBM diagnostic categories were identified. Twelve categories all performed with high (≥97%) specificity but varied substantially in their sensitivities (11%–84%). The best performing category was European Neuromuscular Centre 2013 probable (sensitivity of 84%). Specialized pathologic features and newly introduced strength criteria (comparative knee extension/hip flexion strength) performed poorly. Unbiased data-directed analysis of 20 features in 371 patients resulted in construction of higher-performing data-derived diagnostic criteria (90% sensitivity and 96% specificity). Conclusions: Published expert consensus–derived IBM diagnostic categories have uniformly high specificity but wide-ranging sensitivities. High-performing IBM diagnostic category criteria can be developed directly from principled unbiased analysis of patient data. Classification of evidence: This study provides Class II evidence that published expert consensus–derived IBM diagnostic categories accurately distinguish IBM from other muscle disease with high specificity but wide-ranging sensitivities. PMID:24975859

Performance of FDG-PET/CT in solitary pulmonary nodule based on pre-test likelihood of malignancy: results from the ITALIAN retrospective multicenter trial.

PubMed

Evangelista, Laura; Cuocolo, Alberto; Pace, Leonardo; Mansi, Luigi; Del Vecchio, Silvana; Miletto, Paolo; Sanfilippo, Silvia; Pellegrino, Sara; Guerra, Luca; Pepe, Giovanna; Peluso, Giuseppina; Salvatore, Marco; Galicchio, Rosj; Zuffante, Michele; Annunziata, Salvatore; Farsad, Mohsen; Chiaravalloti, Agostino; Spadafora, Marco

2018-05-07

The aim of this study was to determine the performance of 18 F-FDG-PET/CT in patients with solitary pulmonary nodule (SPN), stratifying the risk according to the likelihood of pulmonary malignancy. FDG-PET/CT of 502 patients, stratified for pre-test cancer risk, were retrospectively analyzed. FDG uptake in SPN was assessed by a 4-point scoring system and semiquantitative analysis using the ratio between SUVmax in SPN and SUVmean in mediastinal blood pool (BP) and between SUVmax in SPN and SUVmean in liver (L). Histopathology and/or follow-up data were used as standard of reference. SPN was malignant in 180 (36%) patients, benign in 175 (35%), and indeterminate in 147 (29%). The 355 patients with a definitive SPN nature (malignant or benign) were considered for the analysis. Considering FDG uptake ≥ 2, sensitivity, specificity, positive (PPV) and negative (NPV) predictive values, and accuracy were 85.6%, 85.7%, 86%, 85.2%, and 85.6% respectively. Sensitivity and PPV were higher (P < 0.05) in intermediate and high-risk patients, while specificity and NPV were higher (P < 0.05) in low-risk patients. On receiver operating characteristic curve analysis, the cut-offs for better discrimination between benign and malignant SPN were 1.56 (sensitivity 81% and specificity 87%) and 1.12 (sensitivity 81% and specificity 86%) for SUVmax/SUVmeanBP and SUVmax/SUVmeanL respectively. In intermediate and high-risk patients, including the SUVmax/SUVmeanBP, the specificity shifted from 85% and 50% to 100%. Visual FDG-PET/CT has an acceptable performance in patients with SPN, but accuracy improves when SUVratios are considered, particularly in patients with intermediate and high risk of malignancy.

The Clinical Utility of Methicillin Resistant Staphylococcus aureus (MRSA) Nasal Screening to Rule Out MRSA Pneumonia: A Diagnostic Meta-analysis with Antimicrobial Stewardship Implications.

PubMed

Parente, Diane M; Cunha, Cheston B; Mylonakis, Eleftherios; Timbrook, Tristan T

2018-01-11

Recent literature has highlighted MRSA nasal screening as a possible antimicrobial stewardship program (ASP) tool for avoiding unnecessary empiric MRSA therapy for pneumonia, yet current guidelines recommend MRSA therapy based on risk factors. The objective of this meta-analysis was to evaluate the diagnostic value of MRSA nasal screening in MRSA pneumonia. Pubmed and EMBASE were searched from inception to November 2016 for English studies evaluating MRSA nasal screening and development of MRSA pneumonia. Data analysis was performed using a bivariate random-effects model to estimate pooled sensitivity, specificity, and positive (PPV) and negative (NPV) predictive values. Twenty-two studies, comprising of 5,163 patients met our inclusion criteria. Pooled sensitivity and specificity of MRSA nares screen for all MRSA pneumonia types was 70.9% and 90.3%, respectively. With a 10% prevalence of potential MRSA pneumonia, the calculated PPV was 44.8% while the NPV was 96.5%. The pooled sensitivity and specificity for MRSA community-acquired pneumonia (CAP) and healthcare-associated pneumonia (HCAP) were at 85% and 92.1%, respectively. For CAP and HCAP both the PPV and NPV increased to 56.8% and 98.1%, respectively. In comparison, for MRSA ventilated-associated pneumonia (VAP), the sensitivity, specificity, PPV, NPV was 40.3%, 93.7%, 35.7%, and 94.8%, respectively. Nares screening for MRSA had a high specificity and NPV for ruling out MRSA pneumonia, particularly in cases of CAP/HCAP. Based on the NPV, utilization of MRSA nares screening is a valuable tool for AMS to streamline empiric antibiotic therapy, especially among patients with pneu. © The Author(s) 2018. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

A five-year model to assess the early cost-effectiveness of new diagnostic tests in the early diagnosis of rheumatoid arthritis.

PubMed

Buisman, Leander R; Luime, Jolanda J; Oppe, Mark; Hazes, Johanna M W; Rutten-van Mölken, Maureen P M H

2016-06-10

There is a lack of information about the sensitivity, specificity and costs new diagnostic tests should have to improve early diagnosis of rheumatoid arthritis (RA). Our objective was to explore the early cost-effectiveness of various new diagnostic test strategies in the workup of patients with inflammatory arthritis (IA) at risk of having RA. A decision tree followed by a patient-level state transition model, using data from published literature, cohorts and trials, was used to evaluate diagnostic test strategies. Alternative tests were assessed as add-on to or replacement of the ACR/EULAR 2010 RA classification criteria for all patients and for intermediate-risk patients. Tests included B-cell gene expression (sensitivity 0.60, specificity 0.90, costs €150), MRI (sensitivity 0.90, specificity 0.60, costs €756), IL-6 serum level (sensitivity 0.70, specificity 0.53, costs €50) and genetic assay (sensitivity 0.40, specificity 0.85, costs €750). Patients with IA at risk of RA were followed for 5 years using a societal perspective. Guideline treatment was assumed using tight controlled treatment based on DAS28; if patients had a DAS28 >3.2 at 12 months or later patients could be eligible for starting biological drugs. The outcome was expressed in incremental cost-effectiveness ratios (€2014 per quality-adjusted life year (QALY) gained) and headroom. The B-cell test was the least expensive strategy when used as an add-on and as replacement in intermediate-risk patients, making it the dominant strategy, as it has better health outcomes and lower costs. As add-on for all patients, the B-cell test was also the most cost-effective test strategy. When using a willingness-to-pay threshold of €20,000 per QALY gained, the IL-6 and MRI strategies were not cost-effective, except as replacement. A genetic assay was not cost-effective in any strategy. Probabilistic sensitivity analysis revealed that the B-cell test was consistently superior in all strategies. When performing univariate sensitivity analysis for intermediate-risk patients, specificity and DAS28 in the B-cell add-on strategy, and DAS28 and sensitivity in the MRI add-on strategy had the largest impact on the cost-effectiveness. This early cost-effectiveness analysis indicated that new tests to diagnose RA are most likely to be cost-effective when the tests are used as an add-on in intermediate-risk patients, and have high specificity, and the test costs should not be higher than €200-€300.

An experimental analysis of disgust sensitivity and fear of contagion in Spider and Blood Injection Injury Phobia.

PubMed

Bianchi, Kristin N; Carter, Michele M

2012-10-01

Disgust sensitivity and concern with contamination have been frequently associated with Spider and Blood-Injection-Injury (BII) Phobias. This study assessed the domain specificity of disgust sensitivity and concern with contamination in 29 Non-Phobic Controls, 25 clinical Spider Phobics, 26 clinical BII Phobics, and 27 persons who met clinical criteria for Spider Phobia and BII Phobia. On self-report measures we found evidence of domain specificity of disgust sensitivity for the Spider and BII Phobia groups. Furthermore, we found that persons with both phobias may be more disgust sensitive than persons with a single phobia. Interestingly, the animal reminder disgust stimulus used in this research was more sensitive to detecting domain specific differences in disgust sensitivity between Phobic groups than was the core disgust stimulus, emphasizing the importance of developing standardized behavioral measures of disgust sensitivity in future research. Lastly, findings from this research suggest that concern with contamination may be more influential in phobic avoidance for persons with Spider Phobia than for persons with BII Phobia. Treatment implications for these findings are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

Novel methods of time-resolved fluorescence data analysis for in-vivo tissue characterization: application to atherosclerosis.

PubMed

Jo, J A; Fang, Q; Papaioannou, T; Qiao, J H; Fishbein, M C; Dorafshar, A; Reil, T; Baker, D; Freischlag, J; Marcu, L

2004-01-01

This study investigates the ability of new analytical methods of time-resolved laser-induced fluorescence spectroscopy (TR-LIFS) data to characterize tissue in-vivo, such as the composition of atherosclerotic vulnerable plaques. A total of 73 TR-LIFS measurements were taken in-vivo from the aorta of 8 rabbits, and subsequently analyzed using the Laguerre deconvolution technique. The investigated spots were classified as normal aorta, thin or thick lesions, and lesions rich in either collagen or macrophages/foam-cells. Different linear and nonlinear classification algorithms (linear discriminant analysis, stepwise linear discriminant analysis, principal component analysis, and feedforward neural networks) were developed using spectral and TR features (ratios of intensity values and Laguerre expansion coefficients, respectively). Normal intima and thin lesions were discriminated from thick lesions (sensitivity >90%, specificity 100%) using only spectral features. However, both spectral and time-resolved features were necessary to discriminate thick lesions rich in collagen from thick lesions rich in foam cells (sensitivity >85%, specificity >93%), and thin lesions rich in foam cells from normal aorta and thin lesions rich in collagen (sensitivity >85%, specificity >94%). Based on these findings, we believe that TR-LIFS information derived from the Laguerre expansion coefficients can provide a valuable additional dimension for in-vivo tissue characterization.

Based on surface-enhanced Raman spectroscopy analysis of serum albumin in different stages of liver disease for early screening primary liver cancer

NASA Astrophysics Data System (ADS)

Liao, Fadian; Ruan, Qiuyong; Lin, Juqiang; Lin, Jinyong; Zeng, Yongyi; Li, Ling; Huang, Zufang; Liu, Nenrong; Chen, Rong

2014-09-01

Despite the introduction of high-technology methods of detection and diagnosis, screening of primary liver cancer (PLC) remains imperfect. To diagnosis PLC earlier, Surface-enhanced Raman spectroscopy (SERS) coupled with cellulose-acetate membrane electrophoresis were introduced to separate human serum albumin and SERS spectra. Three groups (15 normal persons' samples, 17 hepatitis/cirrhosis samples, 15 cases of PLC) of serum albumin were tested. Silver colloid was used to obtain SERS spectra of human serum albumin. Principal component analysis (PCA) and linear discriminant analysis (LDA) were also employed for statistical analysis. The mean Raman spectra of three groups and the difference spectra of any two suggested that the albumin has changed in liver patients. Compared to normal groups, some Raman peaks have shifted or even disappeared in hepatitis/cirrhosis and PLCs groups. The sensitivity and specificity between PLCs and normal groups is 80% and 93.3%. Among hepatitis/cirrhosis and normal groups, the sensitivity is 88.2% and specificity is also 93.3%. Besides, the sensitivity and specificity between PLCs and hepatitis/cirrhosis groups is 86.7% and 76.5%. All the above data and results indicated that early screening of PLC is potential by SERS in different stages of liver disease before cancer occurs.

Breast-specific gamma camera imaging with 99mTc-MIBI has better diagnostic performance than magnetic resonance imaging in breast cancer patients: A meta-analysis.

PubMed

Zhang, Aimi; Li, Panli; Liu, Qiufang; Song, Shaoli

2017-01-01

This study aimed to evaluate the diagnostic role of breast-specific gamma camera imaging (BSGI) with technetium-99m-methoxy isobutyl isonitrile ( 99m Tc-MIBI) and magnetic resonance imaging (MRI) in patients with breast cancer through a meta-analysis. Three reviewers searched articles published in medical journals before June 2016 in MEDLINE, EMBASE and Springer Databases; the references listed in original articles were also retrieved. We used the quality assessment of diagnostic accuracy studies (QUADAS) tool to assess the quality of the included studies. Heterogeneity, pooled sensitivity and specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio (DOR) and summary receiver operating characteristic (SROC) curves were calculated by Meta-DiSc software to estimate the diagnostic performance of BSGI and MRI. Ten studies with 517 patients were included after meeting the inclusion criteria. We did a subgroup analysis of the same data type. The pooled sensitivities of BSGI and MRI were: 0.84 (95% CI, 0.79-0.88) and 0.89 (95% CI, 0.84-0.92) respectively, and the pooled specificities of BSGI and MRI were: 0.82 (95% CI, 0.74-0.88) and 0.39 (95% CI, 0.30-0.49) respectively. The areas under the SROC curve of BSGI and MRI were 0.93 and 0.72 respectively. The results of our meta-analysis indicated that compared with MRI, BSGI has similar sensitivity, higher specificity, better diagnostic performance, and can be widely used in clinical practice.

Diagnostic value of 18F-FDG-PET/CT for the evaluation of solitary pulmonary nodules: a systematic review and meta-analysis.

PubMed

Ruilong, Zong; Daohai, Xie; Li, Geng; Xiaohong, Wang; Chunjie, Wang; Lei, Tian

2017-01-01

To carry out a meta-analysis on the performance of fluorine-18-fluorodeoxyglucose (F-FDG) PET/computed tomography (PET/CT) for the evaluation of solitary pulmonary nodules. In the meta-analysis, we performed searches of several electronic databases for relevant studies, including Google Scholar, PubMed, Cochrane Library, and several Chinese databases. The quality of all included studies was assessed by Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2). Two observers independently extracted data of eligible articles. For the meta-analysis, the total sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratios were pooled. A summary receiver operating characteristic curve was constructed. The I-test was performed to assess the impact of study heterogeneity on the results of the meta-analysis. Meta-regression and subgroup analysis were carried out to investigate the potential covariates that might have considerable impacts on heterogeneity. Overall, 12 studies were included in this meta-analysis, including a total of 1297 patients and 1301 pulmonary nodules. The pooled sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio with corresponding 95% confidence intervals (CIs) were 0.82 (95% CI, 0.76-0.87), 0.81 (95% CI, 0.66-0.90), 4.3 (95% CI, 2.3-7.9), and 0.22 (95% CI, 0.16-0.30), respectively. Significant heterogeneity was observed in sensitivity (I=81.1%) and specificity (I=89.6%). Subgroup analysis showed that the best results for sensitivity (0.90; 95% CI, 0.68-0.86) and accuracy (0.93; 95% CI, 0.90-0.95) were present in a prospective study. The results of our analysis suggest that PET/CT is a useful tool for detecting malignant pulmonary nodules qualitatively. Although current evidence showed moderate accuracy for PET/CT in differentiating malignant from benign solitary pulmonary nodules, further work needs to be carried out to improve its reliability.

Can Automated Imaging for Optic Disc and Retinal Nerve Fiber Layer Analysis Aid Glaucoma Detection?

PubMed

Banister, Katie; Boachie, Charles; Bourne, Rupert; Cook, Jonathan; Burr, Jennifer M; Ramsay, Craig; Garway-Heath, David; Gray, Joanne; McMeekin, Peter; Hernández, Rodolfo; Azuara-Blanco, Augusto

2016-05-01

To compare the diagnostic performance of automated imaging for glaucoma. Prospective, direct comparison study. Adults with suspected glaucoma or ocular hypertension referred to hospital eye services in the United Kingdom. We evaluated 4 automated imaging test algorithms: the Heidelberg Retinal Tomography (HRT; Heidelberg Engineering, Heidelberg, Germany) glaucoma probability score (GPS), the HRT Moorfields regression analysis (MRA), scanning laser polarimetry (GDx enhanced corneal compensation; Glaucoma Diagnostics (GDx), Carl Zeiss Meditec, Dublin, CA) nerve fiber indicator (NFI), and Spectralis optical coherence tomography (OCT; Heidelberg Engineering) retinal nerve fiber layer (RNFL) classification. We defined abnormal tests as an automated classification of outside normal limits for HRT and OCT or NFI ≥ 56 (GDx). We conducted a sensitivity analysis, using borderline abnormal image classifications. The reference standard was clinical diagnosis by a masked glaucoma expert including standardized clinical assessment and automated perimetry. We analyzed 1 eye per patient (the one with more advanced disease). We also evaluated the performance according to severity and using a combination of 2 technologies. Sensitivity and specificity, likelihood ratios, diagnostic, odds ratio, and proportion of indeterminate tests. We recruited 955 participants, and 943 were included in the analysis. The average age was 60.5 years (standard deviation, 13.8 years); 51.1% were women. Glaucoma was diagnosed in at least 1 eye in 16.8%; 32% of participants had no glaucoma-related findings. The HRT MRA had the highest sensitivity (87.0%; 95% confidence interval [CI], 80.2%-92.1%), but lowest specificity (63.9%; 95% CI, 60.2%-67.4%); GDx had the lowest sensitivity (35.1%; 95% CI, 27.0%-43.8%), but the highest specificity (97.2%; 95% CI, 95.6%-98.3%). The HRT GPS sensitivity was 81.5% (95% CI, 73.9%-87.6%), and specificity was 67.7% (95% CI, 64.2%-71.2%); OCT sensitivity was 76.9% (95% CI, 69.2%-83.4%), and specificity was 78.5% (95% CI, 75.4%-81.4%). Including only eyes with severe glaucoma, sensitivity increased: HRT MRA, HRT GPS, and OCT would miss 5% of eyes, and GDx would miss 21% of eyes. A combination of 2 different tests did not improve the accuracy substantially. Automated imaging technologies can aid clinicians in diagnosing glaucoma, but may not replace current strategies because they can miss some cases of severe glaucoma. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Performance of the high-sensitivity troponin assay in diagnosing acute myocardial infarction: systematic review and meta-analysis

PubMed Central

Al-Saleh, Ayman; Alazzoni, Ashraf; Al Shalash, Saleh; Ye, Chenglin; Mbuagbaw, Lawrence; Thabane, Lehana; Jolly, Sanjit S.

2014-01-01

Background High-sensitivity cardiac troponin assays have been adopted by many clinical centres worldwide; however, clinicians are uncertain how to interpret the results. We sought to assess the utility of these assays in diagnosing acute myocardial infarction (MI). Methods We carried out a systematic review and meta-analysis of studies comparing high-sensitivity with conventional assays of cardiac troponin levels among adults with suspected acute MI in the emergency department. We searched MEDLINE, EMBASE and Cochrane databases up to April 2013 and used bivariable random-effects modelling to obtain summary parameters for diagnostic accuracy. Results We identified 9 studies that assessed the use of high-sensitivity troponin T assays (n = 9186 patients). The summary sensitivity of these tests in diagnosing acute MI at presentation to the emergency department was estimated to be 0.94 (95% confidence interval [CI] 0.89–0.97); for conventional tests, it was 0.72 (95% CI 0.63–0.79). The summary specificity was 0.73 (95% CI 0.64–0.81) for the high-sensitivity assay compared with 0.95 (95% CI 0.93–0.97) for the conventional assay. The differences in estimates of the summary sensitivity and specificity between the high-sensitivity and conventional assays were statistically significant (p < 0.01). The area under the curve was similar for both tests carried out 3–6 hours after presentation. Three studies assessed the use of high-sensitivity troponin I assays and showed similar results. Interpretation Used at presentation to the emergency department, the high-sensitivity cardiac troponin assay has improved sensitivity, but reduced specificity, compared with the conventional troponin assay. With repeated measurements over 6 hours, the area under the curve is similar for both tests, indicating that the major advantage of the high-sensitivity test is early diagnosis. PMID:25295240

Sensitivity Analysis of Biome-Bgc Model for Dry Tropical Forests of Vindhyan Highlands, India

NASA Astrophysics Data System (ADS)

Kumar, M.; Raghubanshi, A. S.

2011-08-01

A process-based model BIOME-BGC was run for sensitivity analysis to see the effect of ecophysiological parameters on net primary production (NPP) of dry tropical forest of India. The sensitivity test reveals that the forest NPP was highly sensitive to the following ecophysiological parameters: Canopy light extinction coefficient (k), Canopy average specific leaf area (SLA), New stem C : New leaf C (SC:LC), Maximum stomatal conductance (gs,max), C:N of fine roots (C:Nfr), All-sided to projected leaf area ratio and Canopy water interception coefficient (Wint). Therefore, these parameters need more precision and attention during estimation and observation in the field studies.

A 3-Year Study of Predictive Factors for Positive and Negative Appendicectomies.

PubMed

Chang, Dwayne T S; Maluda, Melissa; Lee, Lisa; Premaratne, Chandrasiri; Khamhing, Srisongham

2018-03-06

Early and accurate identification or exclusion of acute appendicitis is the key to avoid the morbidity of delayed treatment for true appendicitis or unnecessary appendicectomy, respectively. We aim (i) to identify potential predictive factors for positive and negative appendicectomies; and (ii) to analyse the use of ultrasound scans (US) and computed tomography (CT) scans for acute appendicitis. All appendicectomies that took place at our hospital from the 1st of January 2013 to the 31st of December 2015 were retrospectively recorded. Test results of potential predictive factors of acute appendicitis were recorded. Statistical analysis was performed using Fisher exact test, logistic regression analysis, sensitivity, specificity, and positive and negative predictive values calculation. 208 patients were included in this study. 184 patients had histologically proven acute appendicitis. The other 24 patients had either nonappendicitis pathology or normal appendix. Logistic regression analysis showed statistically significant associations between appendicitis and white cell count, neutrophil count, C-reactive protein, and bilirubin. Neutrophil count was the test with the highest sensitivity and negative predictive values, whereas bilirubin was the test with the highest specificity and positive predictive values (PPV). US and CT scans had high sensitivity and PPV for diagnosing appendicitis. No single test was sufficient to diagnose or exclude acute appendicitis by itself. Combining tests with high sensitivity (abnormal neutrophil count, and US and CT scans) and high specificity (raised bilirubin) may predict acute appendicitis more accurately.

Proteomic Signatures of the Zebrafish (Danio rerio) Embryo: Sensitivity and Specificity in Toxicity Assessment of Chemicals.

PubMed

Hanisch, Karen; Küster, Eberhard; Altenburger, Rolf; Gündel, Ulrike

2010-01-01

Studies using embryos of the zebrafish Danio rerio (DarT) instead of adult fish for characterising the (eco-) toxic potential of chemicals have been proposed as animal replacing methods. Effect analysis at the molecular level might enhance sensitivity, specificity, and predictive value of the embryonal studies. The present paper aimed to test the potential of toxicoproteomics with zebrafish eleutheroembryos for sensitive and specific toxicity assessment. 2-DE-based toxicoproteomics was performed applying low-dose (EC(10)) exposure for 48 h with three-model substances Rotenone, 4,6-dinitro-o-cresol (DNOC) and Diclofenac. By multivariate "pattern-only" PCA and univariate statistical analyses, alterations in the embryonal proteome were detectable in nonetheless visibly intact organisms and treatment with the three substances was distinguishable at the molecular level. Toxicoproteomics enabled the enhancement of sensitivity and specificity of the embryonal toxicity assay and bear the potency to identify protein markers serving as general stress markers and early diagnosis of toxic stress.

Proteomic Signatures of the Zebrafish (Danio rerio) Embryo: Sensitivity and Specificity in Toxicity Assessment of Chemicals

PubMed Central

Hanisch, Karen; Küster, Eberhard; Altenburger, Rolf; Gündel, Ulrike

2010-01-01

Studies using embryos of the zebrafish Danio rerio (DarT) instead of adult fish for characterising the (eco-) toxic potential of chemicals have been proposed as animal replacing methods. Effect analysis at the molecular level might enhance sensitivity, specificity, and predictive value of the embryonal studies. The present paper aimed to test the potential of toxicoproteomics with zebrafish eleutheroembryos for sensitive and specific toxicity assessment. 2-DE-based toxicoproteomics was performed applying low-dose (EC10) exposure for 48 h with three-model substances Rotenone, 4,6-dinitro-o-cresol (DNOC) and Diclofenac. By multivariate “pattern-only” PCA and univariate statistical analyses, alterations in the embryonal proteome were detectable in nonetheless visibly intact organisms and treatment with the three substances was distinguishable at the molecular level. Toxicoproteomics enabled the enhancement of sensitivity and specificity of the embryonal toxicity assay and bear the potency to identify protein markers serving as general stress markers and early diagnosis of toxic stress. PMID:22084678

Optical coherence tomography in the diagnosis of dysplasia and adenocarcinoma in Barret's esophagus

NASA Astrophysics Data System (ADS)

Gladkova, N. D.; Zagaynova, E. V.; Zuccaro, G.; Kareta, M. V.; Feldchtein, F. I.; Balalaeva, I. V.; Balandina, E. B.

2007-02-01

Statistical analysis of endoscopic optical coherence tomography (EOCT) surveillance of 78 patients with Barrett's esophagus (BE) is presented in this study. The sensitivity of OCT device in retrospective open detection of early malignancy (including high grade dysplasia and intramucosal adenocarcinoma (IMAC)) was 75%, specificity 82%, diagnostic accuracy - 80%, positive predictive value- 60%, negative predictive value- 87%. In the open recognition of IMAC sensitivity was 81% and specificity were 85% each. Results of a blind recognition with the same material were similar: sensitivity - 77%, specificity 85%, diagnostic accuracy - 82%, positive predictive value- 70%, negative predictive value- 87%. As the endoscopic detection of early malignancy is problematic, OCT holds great promise in enhancing the diagnostic capability of clinical GI endoscopy.

The performance of magnetic resonance imaging in the detection of triangular fibrocartilage complex injury: a meta-analysis.

PubMed

Wang, Z X; Chen, S L; Wang, Q Q; Liu, B; Zhu, J; Shen, J

2015-06-01

The aim of this study was to evaluate the accuracy of magnetic resonance imaging in the detection of triangular fibrocartilage complex injury through a meta-analysis. A comprehensive literature search was conducted before 1 April 2014. All studies comparing magnetic resonance imaging results with arthroscopy or open surgery findings were reviewed, and 25 studies that satisfied the eligibility criteria were included. Data were pooled to yield pooled sensitivity and specificity, which were respectively 0.83 and 0.82. In detection of central and peripheral tears, magnetic resonance imaging had respectively a pooled sensitivity of 0.90 and 0.88 and a pooled specificity of 0.97 and 0.97. Six high-quality studies using Ringler's recommended magnetic resonance imaging parameters were selected for analysis to determine whether optimal imaging protocols yielded better results. The pooled sensitivity and specificity of these six studies were 0.92 and 0.82, respectively. The overall accuracy of magnetic resonance imaging was acceptable. For peripheral tears, the pooled data showed a relatively high accuracy. Magnetic resonance imaging with appropriate parameters are an ideal method for diagnosing different types of triangular fibrocartilage complex tears. © The Author(s) 2015.

Meta-analysis for the comparison of two diagnostic tests to a common gold standard: A generalized linear mixed model approach.

PubMed

Hoyer, Annika; Kuss, Oliver

2018-05-01

Meta-analysis of diagnostic studies is still a rapidly developing area of biostatistical research. Especially, there is an increasing interest in methods to compare different diagnostic tests to a common gold standard. Restricting to the case of two diagnostic tests, in these meta-analyses the parameters of interest are the differences of sensitivities and specificities (with their corresponding confidence intervals) between the two diagnostic tests while accounting for the various associations across single studies and between the two tests. We propose statistical models with a quadrivariate response (where sensitivity of test 1, specificity of test 1, sensitivity of test 2, and specificity of test 2 are the four responses) as a sensible approach to this task. Using a quadrivariate generalized linear mixed model naturally generalizes the common standard bivariate model of meta-analysis for a single diagnostic test. If information on several thresholds of the tests is available, the quadrivariate model can be further generalized to yield a comparison of full receiver operating characteristic (ROC) curves. We illustrate our model by an example where two screening methods for the diagnosis of type 2 diabetes are compared.

A retrospective analysis to identify the factors affecting infection in patients undergoing chemotherapy.

PubMed

Park, Ji Hyun; Kim, Hyeon-Young; Lee, Hanna; Yun, Eun Kyoung

2015-12-01

This study compares the performance of the logistic regression and decision tree analysis methods for assessing the risk factors for infection in cancer patients undergoing chemotherapy. The subjects were 732 cancer patients who were receiving chemotherapy at K university hospital in Seoul, Korea. The data were collected between March 2011 and February 2013 and were processed for descriptive analysis, logistic regression and decision tree analysis using the IBM SPSS Statistics 19 and Modeler 15.1 programs. The most common risk factors for infection in cancer patients receiving chemotherapy were identified as alkylating agents, vinca alkaloid and underlying diabetes mellitus. The logistic regression explained 66.7% of the variation in the data in terms of sensitivity and 88.9% in terms of specificity. The decision tree analysis accounted for 55.0% of the variation in the data in terms of sensitivity and 89.0% in terms of specificity. As for the overall classification accuracy, the logistic regression explained 88.0% and the decision tree analysis explained 87.2%. The logistic regression analysis showed a higher degree of sensitivity and classification accuracy. Therefore, logistic regression analysis is concluded to be the more effective and useful method for establishing an infection prediction model for patients undergoing chemotherapy. Copyright © 2015 Elsevier Ltd. All rights reserved.

Diagnostic potential of real-time elastography (RTE) and shear wave elastography (SWE) to differentiate benign and malignant thyroid nodules

PubMed Central

Hu, Xiangdong; Liu, Yujiang; Qian, Linxue

2017-01-01

Abstract Background: Real-time elastography (RTE) and shear wave elastography (SWE) are noninvasive and easily available imaging techniques that measure the tissue strain, and it has been reported that the sensitivity and the specificity of elastography were better in differentiating between benign and malignant thyroid nodules than conventional technologies. Methods: Relevant articles were searched in multiple databases; the comparison of elasticity index (EI) was conducted with the Review Manager 5.0. Forest plots of the sensitivity and specificity and SROC curve of RTE and SWE were performed with STATA 10.0 software. In addition, sensitivity analysis and bias analysis of the studies were conducted to examine the quality of articles; and to estimate possible publication bias, funnel plot was used and the Egger test was conducted. Results: Finally 22 articles which eventually satisfied the inclusion criteria were included in this study. After eliminating the inefficient, benign and malignant nodules were 2106 and 613, respectively. The meta-analysis suggested that the difference of EI between benign and malignant nodules was statistically significant (SMD = 2.11, 95% CI [1.67, 2.55], P < .00001). The overall sensitivities of RTE and SWE were roughly comparable, whereas the difference of specificities between these 2 methods was statistically significant. In addition, statistically significant difference of AUC between RTE and SWE was observed between RTE and SWE (P < .01). Conclusion: The specificity of RTE was statistically higher than that of SWE; which suggests that compared with SWE, RTE may be more accurate on differentiating benign and malignant thyroid nodules. PMID:29068996

Diagnosis of human malignancies using laser-induced breakdown spectroscopy in combination with chemometric methods

NASA Astrophysics Data System (ADS)

Chen, Xue; Li, Xiaohui; Yu, Xin; Chen, Deying; Liu, Aichun

2018-01-01

Diagnosis of malignancies is a challenging clinical issue. In this work, we present quick and robust diagnosis and discrimination of lymphoma and multiple myeloma (MM) using laser-induced breakdown spectroscopy (LIBS) conducted on human serum samples, in combination with chemometric methods. The serum samples collected from lymphoma and MM cancer patients and healthy controls were deposited on filter papers and ablated with a pulsed 1064 nm Nd:YAG laser. 24 atomic lines of Ca, Na, K, H, O, and N were selected for malignancy diagnosis. Principal component analysis (PCA), linear discriminant analysis (LDA), quadratic discriminant analysis (QDA), and k nearest neighbors (kNN) classification were applied to build the malignancy diagnosis and discrimination models. The performances of the models were evaluated using 10-fold cross validation. The discrimination accuracy, confusion matrix and receiver operating characteristic (ROC) curves were obtained. The values of area under the ROC curve (AUC), sensitivity and specificity at the cut-points were determined. The kNN model exhibits the best performances with overall discrimination accuracy of 96.0%. Distinct discrimination between malignancies and healthy controls has been achieved with AUC, sensitivity and specificity for healthy controls all approaching 1. For lymphoma, the best discrimination performance values are AUC = 0.990, sensitivity = 0.970 and specificity = 0.956. For MM, the corresponding values are AUC = 0.986, sensitivity = 0.892 and specificity = 0.994. The results show that the serum-LIBS technique can serve as a quick, less invasive and robust method for diagnosis and discrimination of human malignancies.

Diagnosis of tuberculosis pleurisy with adenosine deaminase (ADA): a systematic review and meta-analysis.

PubMed

Gui, Xuwei; Xiao, Heping

2014-01-01

This systematic review and meta-analysis was performed to determine accuracy and usefulness of adenosine deaminase (ADA) in diagnosis of tuberculosis pleurisy. Medline, Google scholar and Web of Science databases were searched to identify related studies until 2014. Two reviewers independently assessed quality of studies included according to standard Quality Assessment of Diagnosis Accuracy Studies (QUADAS) criteria. The sensitivity, specificity, diagnostic odds ratio and other parameters of ADA in diagnosis of tuberculosis pleurisy were analyzed with Meta-DiSC1.4 software, and pooled using the random effects model. Twelve studies including 865 tuberculosis pleurisy patients and 1379 non-tuberculosis pleurisy subjects were identified from 110 studies for this meta-analysis. The sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR) and diagnosis odds ratio (DOR) of ADA in the diagnosis of tuberculosis pleurisy were 45.25 (95% CI 27.63-74.08), 0.86 (95% CI 0.84-0.88), 0.88 (95% CI 0.86-0.90), 6.32 (95% CI 4.83-8.26) and 0.15 (95% 0.11-0.22), respectively. The area under the summary receiver operating characteristic curve (SROC) was 0.9340. Our results demonstrate that the sensitivity and specificity of ADA are high in the diagnosis of tuberculosis pleurisy especially when ADA≥50 (U/L). Thus, ADA is a relatively sensitive and specific marker for tuberculosis pleurisy diagnosis. However, it is cautious to apply these results due to the heterogeneity in study design of these studies. Further studies are required to confirm the optimal cut-off value of ADA.

Sensitivity and Specificity of Eustachian Tube Function Tests in Adults

PubMed Central

Doyle, William J.; Swarts, J. Douglas; Banks, Julianne; Casselbrant, Margaretha L; Mandel, Ellen M; Alper, Cuneyt M.

2013-01-01

Objective Determine if Eustachian Tube (ET) function (ETF) tests can identify ears with physician-diagnosed ET dysfunction (ETD) in a mixed population at high sensitivity and specificity and define the inter-relatedness of ETF test parameters. Methods ETF was evaluated using the Forced-Response, Inflation-Deflation, Valsalva and Sniffing tests in 15 control ears of adult subjects after unilateral myringotomy (Group I) and in 23 ears of 19 adult subjects with ventilation tubes inserted for ETD (Group II). Data were analyzed using logistic regression including each parameter independently and then a step-down Discriminant Analysis including all ETF test parameters to predict group assignment. Factor Analysis operating over all parameters was used to explore relatedness. Results The Discriminant Analysis identified 4 ETF test parameters (Valsalva, ET opening pressure, dilatory efficiency and % positive pressure equilibrated) that together correctly assigned ears to Group II at a sensitivity of 95% and a specificity of 83%. Individual parameters representing the efficiency of ET opening during swallowing showed moderately accurate assignments of ears to their respective groups. Three factors captured approximately 98% of the variance among parameters, the first had negative loadings of the ETF structural parameters, the second had positive loadings of the muscle-assisted ET opening parameters and the third had negative loadings of the muscle-assisted ET opening parameters and positive loadings of the structural parameters. Discussion These results show that ETF tests can correctly assign individual ears to physician-diagnosed ETD with high sensitivity and specificity and that ETF test parameters can be grouped into structural-functional categories. PMID:23868429

Thalamic functional connectivity predicts seizure laterality in individual TLE patients: application of a biomarker development strategy.

PubMed

Barron, Daniel S; Fox, Peter T; Pardoe, Heath; Lancaster, Jack; Price, Larry R; Blackmon, Karen; Berry, Kristen; Cavazos, Jose E; Kuzniecky, Ruben; Devinsky, Orrin; Thesen, Thomas

2015-01-01

Noninvasive markers of brain function could yield biomarkers in many neurological disorders. Disease models constrained by coordinate-based meta-analysis are likely to increase this yield. Here, we evaluate a thalamic model of temporal lobe epilepsy that we proposed in a coordinate-based meta-analysis and extended in a diffusion tractography study of an independent patient population. Specifically, we evaluated whether thalamic functional connectivity (resting-state fMRI-BOLD) with temporal lobe areas can predict seizure onset laterality, as established with intracranial EEG. Twenty-four lesional and non-lesional temporal lobe epilepsy patients were studied. No significant differences in functional connection strength in patient and control groups were observed with Mann-Whitney Tests (corrected for multiple comparisons). Notwithstanding the lack of group differences, individual patient difference scores (from control mean connection strength) successfully predicted seizure onset zone as shown in ROC curves: discriminant analysis (two-dimensional) predicted seizure onset zone with 85% sensitivity and 91% specificity; logistic regression (four-dimensional) achieved 86% sensitivity and 100% specificity. The strongest markers in both analyses were left thalamo-hippocampal and right thalamo-entorhinal cortex functional connection strength. Thus, this study shows that thalamic functional connections are sensitive and specific markers of seizure onset laterality in individual temporal lobe epilepsy patients. This study also advances an overall strategy for the programmatic development of neuroimaging biomarkers in clinical and genetic populations: a disease model informed by coordinate-based meta-analysis was used to anatomically constrain individual patient analyses.

Identifying Depressed Older Adults in Primary Care: A Secondary Analysis of a Multisite Randomized Controlled Trial

PubMed Central

Voils, Corrine I.; Olsen, Maren K.; Williams, John W.; for the IMPACT Study Investigators

2008-01-01

Objective: To determine whether a subset of depressive symptoms could be identified to facilitate diagnosis of depression in older adults in primary care. Method: Secondary analysis was conducted on 898 participants aged 60 years or older with major depressive disorder and/or dysthymic disorder (according to DSM-IV criteria) who participated in the Improving Mood–Promoting Access to Collaborative Treatment (IMPACT) study, a multisite, randomized trial of collaborative care for depression (recruitment from July 1999 to August 2001). Linear regression was used to identify a core subset of depressive symptoms associated with decreased social, physical, and mental functioning. The sensitivity and specificity, adjusting for selection bias, were evaluated for these symptoms. The sensitivity and specificity of a second subset of 4 depressive symptoms previously validated in a midlife sample was also evaluated. Results: Psychomotor changes, fatigue, and suicidal ideation were associated with decreased functioning and served as the core set of symptoms. Adjusting for selection bias, the sensitivity of these 3 symptoms was 0.012 and specificity 0.994. The sensitivity of the 4 symptoms previously validated in a midlife sample was 0.019 and specificity was 0.997. Conclusion: We identified 3 depression symptoms that were highly specific for major depressive disorder in older adults. However, these symptoms and a previously identified subset were too insensitive for accurate diagnosis. Therefore, we recommend a full assessment of DSM-IV depression criteria for accurate diagnosis. PMID:18311416

Systematic Review and Meta-Analysis of Studies Evaluating Diagnostic Test Accuracy: A Practical Review for Clinical Researchers-Part II. Statistical Methods of Meta-Analysis

PubMed Central

Lee, Juneyoung; Kim, Kyung Won; Choi, Sang Hyun; Huh, Jimi

2015-01-01

Meta-analysis of diagnostic test accuracy studies differs from the usual meta-analysis of therapeutic/interventional studies in that, it is required to simultaneously analyze a pair of two outcome measures such as sensitivity and specificity, instead of a single outcome. Since sensitivity and specificity are generally inversely correlated and could be affected by a threshold effect, more sophisticated statistical methods are required for the meta-analysis of diagnostic test accuracy. Hierarchical models including the bivariate model and the hierarchical summary receiver operating characteristic model are increasingly being accepted as standard methods for meta-analysis of diagnostic test accuracy studies. We provide a conceptual review of statistical methods currently used and recommended for meta-analysis of diagnostic test accuracy studies. This article could serve as a methodological reference for those who perform systematic review and meta-analysis of diagnostic test accuracy studies. PMID:26576107

High Sensitivity and High Detection Specificity of Gold-Nanoparticle-Grafted Nanostructured Silicon Mass Spectrometry for Glucose Analysis.

PubMed

Tsao, Chia-Wen; Yang, Zhi-Jie

2015-10-14

Desorption/ionization on silicon (DIOS) is a high-performance matrix-free mass spectrometry (MS) analysis method that involves using silicon nanostructures as a matrix for MS desorption/ionization. In this study, gold nanoparticles grafted onto a nanostructured silicon (AuNPs-nSi) surface were demonstrated as a DIOS-MS analysis approach with high sensitivity and high detection specificity for glucose detection. A glucose sample deposited on the AuNPs-nSi surface was directly catalyzed to negatively charged gluconic acid molecules on a single AuNPs-nSi chip for MS analysis. The AuNPs-nSi surface was fabricated using two electroless deposition steps and one electroless etching step. The effects of the electroless fabrication parameters on the glucose detection efficiency were evaluated. Practical application of AuNPs-nSi MS glucose analysis in urine samples was also demonstrated in this study.

Photoacoustic Spectroscopy Analysis of Traditional Chinese Medicine

NASA Astrophysics Data System (ADS)

Chen, Lu; Zhao, Bin-xing; Xiao, Hong-tao; Tong, Rong-sheng; Gao, Chun-ming

2013-09-01

Chinese medicine is a historic cultural legacy of China. It has made a significant contribution to medicine and healthcare for generations. The development of Chinese herbal medicine analysis is emphasized by the Chinese pharmaceutical industry. This study has carried out the experimental analysis of ten kinds of Chinese herbal powder including Fritillaria powder, etc., based on the photoacoustic spectroscopy (PAS) method. First, a photoacoustic spectroscopy system was designed and constructed, especially a highly sensitive solid photoacoustic cell was established. Second, the experimental setup was verified through the characteristic emission spectrum of the light source, obtained by using carbon as a sample in the photoacoustic cell. Finally, as the photoacoustic spectroscopy analysis of Fritillaria, etc., was completed, the specificity of the Chinese herb medicine analysis was verified. This study shows that the PAS can provide a valid, highly sensitive analytical method for the specificity of Chinese herb medicine without preparing and damaging samples.

Commercial Serological Tests for the Diagnosis of Active Pulmonary and Extrapulmonary Tuberculosis: An Updated Systematic Review and Meta-Analysis

PubMed Central

Steingart, Karen R.; Flores, Laura L.; Dendukuri, Nandini; Schiller, Ian; Laal, Suman; Ramsay, Andrew; Hopewell, Philip C.; Pai, Madhukar

2011-01-01

Background Serological (antibody detection) tests for tuberculosis (TB) are widely used in developing countries. As part of a World Health Organization policy process, we performed an updated systematic review to assess the diagnostic accuracy of commercial serological tests for pulmonary and extrapulmonary TB with a focus on the relevance of these tests in low- and middle-income countries. Methods and Findings We used methods recommended by the Cochrane Collaboration and GRADE approach for rating quality of evidence. In a previous review, we searched multiple databases for papers published from 1 January 1990 to 30 May 2006, and in this update, we add additional papers published from that period until 29 June 2010. We prespecified subgroups to address heterogeneity and summarized test performance using bivariate random effects meta-analysis. For pulmonary TB, we included 67 studies (48% from low- and middle-income countries) with 5,147 participants. For all tests, estimates were variable for sensitivity (0% to 100%) and specificity (31% to 100%). For anda-TB IgG, the only test with enough studies for meta-analysis, pooled sensitivity was 76% (95% CI 63%–87%) in smear-positive (seven studies) and 59% (95% CI 10%–96%) in smear-negative (four studies) patients; pooled specificities were 92% (95% CI 74%–98%) and 91% (95% CI 79%–96%), respectively. Compared with ELISA (pooled sensitivity 60% [95% CI 6%–65%]; pooled specificity 98% [95% CI 96%–99%]), immunochromatographic tests yielded lower pooled sensitivity (53%, 95% CI 42%–64%) and comparable pooled specificity (98%, 95% CI 94%–99%). For extrapulmonary TB, we included 25 studies (40% from low- and middle-income countries) with 1,809 participants. For all tests, estimates were variable for sensitivity (0% to 100%) and specificity (59% to 100%). Overall, quality of evidence was graded very low for studies of pulmonary and extrapulmonary TB. Conclusions Despite expansion of the literature since 2006, commercial serological tests continue to produce inconsistent and imprecise estimates of sensitivity and specificity. Quality of evidence remains very low. These data informed a recently published World Health Organization policy statement against serological tests. Please see later in the article for the Editors' Summary PMID:21857806

Sampling and analysis of airborne resin acids and solvent-soluble material derived from heated colophony (rosin) flux: a method to quantify exposure to sensitizing compounds liberated during electronics soldering.

PubMed

Smith, P A; Son, P S; Callaghan, P M; Jederberg, W W; Kuhlmann, K; Still, K R

1996-07-17

Components of colophony (rosin) resin acids are sensitizers through dermal and pulmonary exposure to heated and unheated material. Significant work in the literature identifies specific resin acids and their oxidation products as sensitizers. Pulmonary exposure to colophony sensitizers has been estimated indirectly through formaldehyde exposure. To assess pulmonary sensitization from airborne resin acids, direct measurement is desired, as the degree to which aldehyde exposure correlates with that of resin acids during colophony heating is undefined. Any analytical method proposed should be applicable to a range of compounds and should also identify specific compounds present in a breathing zone sample. This work adapts OSHA Sampling and Analytical Method 58, which is designed to provide airborne concentration data for coal tar pitch volatile solids by air filtration through a glass fiber filter, solvent extraction of the filter, and gravimetric analysis of the non-volatile extract residue. In addition to data regarding total soluble material captured, a portion of the extract may be subjected to compound-specific analysis. Levels of soluble solids found during personal breathing zone sampling during electronics soldering in a Naval Aviation Depot ranged from below the "reliable quantitation limit" reported in the method to 7.98 mg/m3. Colophony-spiked filters analyzed in accordance with the method (modified) produced a limit of detection for total solvent-soluble colophony solids of 10 micrograms/filter. High performance liquid chromatography was used to identify abietic acid present in a breathing zone sample.

HPAEC-PAD for oligosaccharide analysis-novel insights into analyte sensitivity and response stability.

PubMed

Mechelke, Matthias; Herlet, Jonathan; Benz, J Philipp; Schwarz, Wolfgang H; Zverlov, Vladimir V; Liebl, Wolfgang; Kornberger, Petra

2017-12-01

The rising importance of accurately detecting oligosaccharides in biomass hydrolyzates or as ingredients in food, such as in beverages and infant milk products, demands for the availability of tools to sensitively analyze the broad range of available oligosaccharides. Over the last decades, HPAEC-PAD has been developed into one of the major technologies for this task and represents a popular alternative to state-of-the-art LC-MS oligosaccharide analysis. This work presents the first comprehensive study which gives an overview of the separation of 38 analytes as well as enzymatic hydrolyzates of six different polysaccharides focusing on oligosaccharides. The high sensitivity of the PAD comes at cost of its stability due to recession of the gold electrode. By an in-depth analysis of the sensitivity drop over time for 35 analytes, including xylo- (XOS), arabinoxylo- (AXOS), laminari- (LOS), manno- (MOS), glucomanno- (GMOS), and cellooligosaccharides (COS), we developed an analyte-specific one-phase decay model for this effect over time. Using this model resulted in significantly improved data normalization when using an internal standard. Our results thereby allow a quantification approach which takes the inevitable and analyte-specific PAD response drop into account. Graphical abstract HPAEC-PAD analysis of oligosaccharides and determination of PAD response drop leading to an improved data normalization.

Histopathology of valves in infective endocarditis, diagnostic criteria and treatment considerations.

PubMed

Brandão, Tatiana J D; Januario-da-Silva, Carolina A; Correia, Marcelo G; Zappa, Monica; Abrantes, Jaime A; Dantas, Angela M R; Golebiovski, Wilma; Barbosa, Giovanna Ianini F; Weksler, Clara; Lamas, Cristiane C

2017-04-01

Infective endocarditis (IE) is a severe disease. Pathogen isolation is fundamental so as to treat effectively and reduce morbidity and mortality. Blood and valve culture and histopathology (HP) are routinely employed for this purpose. Valve HP is the gold standard for diagnosis. To determine the sensitivity and specificity of clinical criteria for IE (the modified Duke and the St Thomas' minor modifications, STH) of blood and valve culture compared to valve HP, and to evaluate antibiotic treatment duration. Prospective case series of patients, from 2006 to 2014 with surgically treated IE. Statistical analysis was done by the R software. There were 136 clinically definite episodes of IE in 133 patients. Mean age ± SD was 43 ± 15.6 years and IE was left sided in 81.6 %. HP was definite in 96 valves examined, which were used as gold standard. Sensitivity of blood culture was 61 % (CI 0.51, 0.71) and of valve culture 15 % (CI 0.07, 0.26). The modified Duke criteria were 65 % (CI 0.55, 0.75) sensitive and 33 % specific, while the STH's sensitivity was 72 % (CI 0.61, 0.80) with similar specificity. In multivariate analysis and logistic regression, the only variable with statistical significance was duration of antibiotic therapy postoperatively. Valve HP had high sensitivity and valve culture low sensitivity in the diagnosis of IE. The STH's criteria were more sensitive than the modified Duke criteria. Valve HP should guide duration of postoperative antibiotic treatment.

Breast Lesions: Diagnosis Using Diffusion Weighted Imaging at 1.5T and 3.0T-Systematic Review and Meta-analysis.

PubMed

Shi, Ruo-Yang; Yao, Qiu-Ying; Wu, Lian-Ming; Xu, Jian-Rong

2018-06-01

We compared the diagnostic performance of diffusion weighted imaging (DWI) acquired with 1.5T and 3.0T magnetic resonance (MR) units in differentiating malignant breast lesions from benign ones. A comprehensive search of the PubMed and Embase databases was performed for studies reported from January 1, 2000 to February 19, 2016. The quality of the included studies was assessed. Statistical analysis included pooling of diagnostic sensitivity and specificity and assessing data inhomogeneity and publication bias. A total of 61 studies were included after a full-text review. These included 4778 patients and 5205 breast lesions. The overall sensitivity and specificity were 90% (95% confidence interval [CI], 88%-92%) and 86% (95% CI, 82%-89%), respectively. The pooled diagnostic odds ratio was 53 (95% CI, 37-74). For breast cancer versus benign lesions, the area under the curve was 0.94 (95% CI, 0.92-0.96). For the 44 studies that used a 1.5T MR unit, the pooled sensitivity and specificity were 91% (95% CI, 89%-92%) and 86% (95% CI, 81%-90%), respectively. For the 17 studies that used a 3.0T MR unit, the pooled sensitivity and specificity were 88% (95% CI, 83%-91%) and 84% (95% CI, 0.78-0.89), respectively. Publication bias and significant heterogeneity were observed; however, no threshold was found among the 61 studies. No significant difference was found in the sensitivity or specificity between the subgroups. The results of the comparison between the subgroups that had used either a 1.5T or 3.0T MR unit suggest that the diagnostic accuracy for breast cancer compared with benign lesions is not significantly different. Copyright © 2017 Elsevier Inc. All rights reserved.

Diagnostic value of sleep stage dissociation as visualized on a 2-dimensional sleep state space in human narcolepsy.

PubMed

Olsen, Anders Vinther; Stephansen, Jens; Leary, Eileen; Peppard, Paul E; Sheungshul, Hong; Jennum, Poul Jørgen; Sorensen, Helge; Mignot, Emmanuel

2017-04-15

Type 1 narcolepsy (NT1) is characterized by symptoms believed to represent Rapid Eye Movement (REM) sleep stage dissociations, occurrences where features of wake and REM sleep are intermingled, resulting in a mixed state. We hypothesized that sleep stage dissociations can be objectively detected through the analysis of nocturnal Polysomnography (PSG) data, and that those affecting REM sleep can be used as a diagnostic feature for narcolepsy. A Linear Discriminant Analysis (LDA) model using 38 features extracted from EOG, EMG and EEG was used in control subjects to select features differentiating wake, stage N1, N2, N3 and REM sleep. Sleep stage differentiation was next represented in a 2D projection. Features characteristic of sleep stage differences were estimated from the residual sleep stage probability in the 2D space. Using this model we evaluated PSG data from NT1 and non-narcoleptic subjects. An LDA classifier was used to determine the best separation plane. This method replicates the specificity/sensitivity from the training set to the validation set better than many other methods. Eight prominent features could differentiate narcolepsy and controls in the validation dataset. Using a composite measure and a specificity cut off 95% in the training dataset, sensitivity was 43%. Specificity/sensitivity was 94%/38% in the validation set. Using hypersomnia subjects, specificity/sensitivity was 84%/15%. Analyzing treated narcoleptics the specificity/sensitivity was 94%/10%. Sleep stage dissociation can be used for the diagnosis of narcolepsy. However the use of some medications and presence of undiagnosed hypersomnolence patients impacts the result. Copyright © 2017 Elsevier B.V. All rights reserved.

Simplified HCC-ART score for highly sensitive detection of small-sized and early-stage hepatocellular carcinoma in the widely used Okuda, CLIP, and BCLC staging systems.

PubMed

Attallah, Abdelfattah M; Omran, Mohamed M; Attallah, Ahmed A; Abdelrazek, Mohamed A; Farid, Khaled; El-Dosoky, Ibrahim

2017-04-01

Small-sized HCC can be effectively cured by surgery with good clinical outcomes. A highly sensitive HCC α-fetoprotein routine test (HCC-ART) for HCC diagnosis as well as a simplied form of the HCC-ART were reported in the British Journal of Cancer. Here, we verified and studied the applicability of the HCC-ART to the detection of early-stage HCC. 341 cirrhotic patients and 318 HCC patients were included in this study. For each, the HCC-ART score was calculated, and then the sensitivity, specificity, and results of an ROC curve analysis were compared between the HCC-ART and AFP when these biomarkers were used to detect small-sized HCC. Different HCC-ART cutoffs were set for the detection of different tumor sizes. The HCC-ART (AUC = 0.871, 70% sensitivity, 97% specificity) and the simplified HCC-ART (AUC = 0.934, 82% sensitivity, 100% specificity) were found to have high predictive power when attempting to separate cirrhotic patients from those with small-sized HCC. The simplified HCC-ART score was superior to AFP for determining stages according to the early Okuda (0.950 AUC, 84% sensitivity, 99% specificity), CLIP (0.945 AUC, 84% sensitivity, 99% specificity), and BCLC (1.000 AUC, 100% sensitivity, 99% specificity) staging systems. The simplified HCC-ART score was more strongly correlated than AFP and other staging systems with HCC tumor size (P < 0.0001; r = 0.8). The HCC-ART is superior to AFP for diagnosing early-stage HCC. Due to its advantages of minimal variability and a wide continuous scale for assessing HCC severity, the simplified HCC-ART has the potential to be more widely used than the original HCC-ART.

Sensitivity analysis of add-on price estimate for select silicon wafering technologies

NASA Technical Reports Server (NTRS)

Mokashi, A. R.

1982-01-01

The cost of producing wafers from silicon ingots is a major component of the add-on price of silicon sheet. Economic analyses of the add-on price estimates and their sensitivity internal-diameter (ID) sawing, multiblade slurry (MBS) sawing and fixed-abrasive slicing technique (FAST) are presented. Interim price estimation guidelines (IPEG) are used for estimating a process add-on price. Sensitivity analysis of price is performed with respect to cost parameters such as equipment, space, direct labor, materials (blade life) and utilities, and the production parameters such as slicing rate, slices per centimeter and process yield, using a computer program specifically developed to do sensitivity analysis with IPEG. The results aid in identifying the important cost parameters and assist in deciding the direction of technology development efforts.

Sensitivity and specificity of the lymphocyte transformation test in drug reaction with eosinophilia and systemic symptoms causality assessment.

PubMed

Cabañas, R; Calderón, O; Ramírez, E; Fiandor, A; Caballero, T; Heredia, R; Herranz, P; Madero, R; Quirce, S; Bellón, T

2018-03-01

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe delayed hypersensitivity reaction. The determination of drug causality is complex. The lymphocyte transformation test (LTT) has been reported positive in more than 50% of DRESS cases. Nevertheless, the sensitivity and specificity of LTT specifically in DRESS have not yet been established. Rechallenge with the culprit drug is contraindicated and cannot be used as gold standard for sensitivity and specificity determination. To estimate the sensitivity and specificity of LTT in a clinically defined series of patients with DRESS. Some 41 patients diagnosed with DRESS were included in the study. The results of the algorithm of the Spanish Pharmacovigilance System were used as the standard for a correct diagnosis of drug causality. A standard LTT was performed with involved drugs in acute or recovery samples. A stimulation index (SI) ≥2 in at least one concentration except for beta-lactams (SI ≥3) and contrast media (SI ≥4) was considered positive. Contingency tables and ROC curves were used for analysis. Sensitivity and specificity of LTT in the recovery phase of DRESS were 73% and 82%, respectively, whereas in the acute phase, they were only 40% and 30%, respectively. Comparison of skin tests and LTT confirmed a higher sensitivity and specificity of LTT in DRESS. LTT showed high sensitivity (S) and specificity (Sp) for anticonvulsants (S 100%, Sp 100%; P = .008), anti-TB drugs (S 87.5%, Sp 100%; P = .004), and beta-lactams (S 73%, Sp 100%; P = .001). ROC curves revealed that the best criteria for LTT positivity for all drugs are SI ≥2 in at least one concentration, increasing overall sensitivity to 80%, and for beta-lactams from 73% to 92%. LTT is a good diagnostic tool for drug causality in DRESS, mainly when performed in the recovery phase. © 2017 John Wiley & Sons Ltd.

Comparison of digital tomosynthesis and chest radiography for the detection of pulmonary nodules: systematic review and meta-analysis.

PubMed

Kim, Jun H; Lee, Kyung H; Kim, Kyoung-Tae; Kim, Hyun J; Ahn, Hyeong S; Kim, Yeo J; Lee, Ha Y; Jeon, Yong S

2016-12-01

To compare the diagnostic accuracy of digital tomosynthesis (DTS) with that of chest radiography for the detection of pulmonary nodules by meta-analysis. A systematic literature search was performed to identify relevant original studies from 1 January 1 1976 to 31 August 31 2016. The quality of included studies was assessed by quality assessment of diagnostic accuracy studies-2. Per-patient data were used to calculate the sensitivity and specificity and per-lesion data were used to calculate the detection rate. Summary receiver-operating characteristic curves were drawn for pulmonary nodule detection. 16 studies met the inclusion criteria. 1017 patients on a per-patient basis and 2159 lesions on a per-lesion basis from 16 eligible studies were evaluated. The pooled patient-based sensitivity of DTS was 0.85 [95% confidence interval (CI) 0.83-0.88] and the specificity was 0.95 (0.93-0.96). The pooled sensitivity and specificity of chest radiography were 0.47 (0.44-0.51) and 0.37 (0.34-0.40), respectively. The per-lesion detection rate was 2.90 (95% CI 2.63-3.19). DTS has higher diagnostic accuracy than chest radiography for detection of pulmonary nodules. Chest radiography has low sensitivity but similar specificity, comparable with that of DTS. Advances in knowledge: DTS has higher diagnostic accuracy than chest radiography for the detection of pulmonary nodules.

Non-invasive assessment of peripheral arterial disease: Automated ankle brachial index measurement and pulse volume analysis compared to duplex scan.

PubMed

Lewis, Jane Ea; Williams, Paul; Davies, Jane H

2016-01-01

This cross-sectional study aimed to individually and cumulatively compare sensitivity and specificity of the (1) ankle brachial index and (2) pulse volume waveform analysis recorded by the same automated device, with the presence or absence of peripheral arterial disease being verified by ultrasound duplex scan. Patients (n=205) referred for lower limb arterial assessment underwent ankle brachial index measurement and pulse volume waveform recording using volume plethysmography, followed by ultrasound duplex scan. The presence of peripheral arterial disease was recorded if ankle brachial index <0.9; pulse volume waveform was graded as 2, 3 or 4; or if haemodynamically significant stenosis >50% was evident with ultrasound duplex scan. Outcome measure was agreement between the measured ankle brachial index and interpretation of pulse volume waveform for peripheral arterial disease diagnosis, using ultrasound duplex scan as the reference standard. Sensitivity of ankle brachial index was 79%, specificity 91% and overall accuracy 88%. Pulse volume waveform sensitivity was 97%, specificity 81% and overall accuracy 85%. The combined sensitivity of ankle brachial index and pulse volume waveform was 100%, specificity 76% and overall accuracy 85%. Combining these two diagnostic modalities within one device provided a highly accurate method of ruling out peripheral arterial disease, which could be utilised in primary care to safely reduce unnecessary secondary care referrals.

[Tumor markers for bladder cancer: up-to-date study by the Kiel Tumor Bank].

PubMed

Hautmann, S; Eggers, J; Meyhoff, H; Melchior, D; Munk, A; Hamann, M; Naumann, M; Braun, P M; Jünemann, K P

2007-11-01

The number of noninvasive diagnostic tests for bladder cancer has increased tremendously over the last years with a large number of experimental and commercial tests. Comparative analyses of tests for diagnosis, follow-up, and recurrence detection of bladder cancer were performed retrospectively as well as prospectively, unicentrically, and multicentrically. An analysis of multicentric studies with large patient numbers compared with our own Kiel Tumor Bank data is presented. The Kiel Tumor Bank data looked prospectively at 106 consecutive bladder tumor patients from the year 2006. Special focus was put on urine cytology as a reference test, as well as the commercial NMP 22 Bladder Chek. The analysis of the NMP 22 Bladder Chek showed an overall sensitivity of 69% for all tumor grades and stages, with a specificity of 76%. Comparison to multicentric data with an overall sensitivity of 75% for all tumor grades and stages, with a specificity of 73%, showed results similar to those in the literature. Urine cytology showed a comparable overall sensitivity of 73% for all tumor grades and stages, with a specificity of 80%. A large number of noninvasive tests for bladder cancer follow-up with reasonable sensitivity and specificity can currently be used. Because of limited numbers of prospective randomized multicentric studies, no single particular marker for bladder cancer screening can be recommended at this point in time.

Analysis of proteins using DIGE and MALDI mass spectrometry

EPA Science Inventory

In this work the sensitivity of the quantitative proteomics approach 2D-DIGE/MS (twoDimensional Difference Gel Electrophoresis / Mass Spectrometry) was tested by detecting decreasing amounts of a specific protein at the low picomole and sub-picomole range. Sensitivity of the 2D-D...

Bowel Ultrasonography in the Management of Crohn's Disease. A Review with Recommendations of an International Panel of Experts.

PubMed

Calabrese, Emma; Maaser, Christian; Zorzi, Francesca; Kannengiesser, Klaus; Hanauer, Stephen B; Bruining, David H; Iacucci, Marietta; Maconi, Giovanni; Novak, Kerri L; Panaccione, Remo; Strobel, Deike; Wilson, Stephanie R; Watanabe, Mamoru; Pallone, Francesco; Ghosh, Subrata

2016-05-01

Bowel ultrasonography (US) is considered a useful technique for assessing mural inflammation and complications in Crohn's disease (CD). The aim of this review is to appraise the evidence on the accuracy of bowel US for CD. In addition, we aim to provide recommendations for its optimal use. Publications were identified by literature search from 1992 to 2014 and selected based on predefined criteria: 15 or more patients; bowel US for diagnosing CD, complications, postoperative recurrence, activity; adequate reference standards; prospective study design; data reported to allow calculation of sensitivity, specificity, agreement, or correlation values; articles published in English. The search yielded 655 articles, of which 63 were found to be eligible and retrieved as full-text articles for analysis. Bowel US showed 79.7% sensitivity and 96.7% specificity for the diagnosis of suspected CD, and 89% sensitivity and 94.3% specificity for initial assessment in established patients with CD. Bowel US identified ileal CD with 92.7% sensitivity, 88.2% specificity, and colon CD with 81.8% sensitivity, 95.3% specificity, with lower accuracy for detecting proximal lesions. The oral contrast agent improves the sensitivity and specificity in determining CD lesions and in assessing sites and extent. Bowel US is a tool for evaluation of CD lesions in terms of complications, postoperative recurrence, and monitoring response to medical therapy; it reliably detects postoperative recurrence and complications, as well as offers the possibility of monitoring disease progression.

Use of the polymerase chain reaction to directly detect malaria parasites in blood samples from the Venezuelan Amazon.

PubMed

Laserson, K F; Petralanda, I; Hamlin, D M; Almera, R; Fuentes, M; Carrasquel, A; Barker, R H

1994-02-01

We have examined the reproducibility, sensitivity, and specificity of detecting Plasmodium falciparum using the polymerase chain reaction (PCR) and the species-specific probe pPF14 under field conditions in the Venezuelan Amazon. Up to eight samples were field collected from each of 48 consenting Amerindians presenting with symptoms of malaria. Sample processing and analysis was performed at the Centro Amazonico para la Investigacion y Control de Enfermedades Tropicales Simon Bolivar. A total of 229 samples from 48 patients were analyzed by PCR methods using four different P. falciparum-specific probes. One P. vivax-specific probe and by conventional microscopy. Samples in which results from PCR and microscopy differed were reanalyzed at a higher sensitivity by microscopy. Results suggest that microscopy-negative, PCR-positive samples are true positives, and that microscopy-positive and PCR-negative samples are true negatives. The sensitivity of the DNA probe/PCR method was 78% and its specificity was 97%. The positive predictive value of the PCR method was 88%, and the negative predictive value was 95%. Through the analysis of multiple blood samples from each individual, the DNA probe/PCR methodology was found to have an inherent reproducibility that was highly statistically significant.

Validity of multislice computerized tomography for diagnosis of maxillofacial fractures using an independent workstation.

PubMed

Dos Santos, Denise Takehana; Costa e Silva, Adriana Paula Andrade; Vannier, Michael Walter; Cavalcanti, Marcelo Gusmão Paraiso

2004-12-01

The purpose of this study was to demonstrate the sensitivity and specificity of multislice computerized tomography (CT) for diagnosis of maxillofacial fractures following specific protocols using an independent workstation. The study population consisted of 56 patients with maxillofacial fractures who were submitted to a multislice CT. The original data were transferred to an independent workstation using volumetric imaging software to generate axial images and simultaneous multiplanar (MPR) and 3-dimensional (3D-CT) volume rendering reconstructed images. The images were then processed and interpreted by 2 examiners using the following protocols independently of each other: axial, MPR/axial, 3D-CT images, and the association of axial/MPR/3D images. The clinical/surgical findings were considered the gold standard corroborating the diagnosis of the fractures and their anatomic localization. The statistical analysis was carried out using validity and chi-squared tests. The association of axial/MPR/3D images indicated a higher sensitivity (range 95.8%) and specificity (range 99%) than the other methods regarding the analysis of all regions. CT imaging demonstrated high specificity and sensitivity for maxillofacial fractures. The association of axial/MPR/3D-CT images added important information in relationship to other CT protocols.

A comparison of standard serological tests for the diagnosis of bovine brucellosis in Canada.

PubMed Central

Stemshorn, B W; Forbes, L B; Eaglesome, M D; Nielsen, K H; Robertson, F J; Samagh, B S

1985-01-01

Six agglutination and two complement fixation tests were compared with respect to specificity, sensitivity and relative sensitivity for the serodiagnosis of bovine brucellosis. Based on 1051 sera from brucellosis free herds, the specificity of the tests was 98.9% for the buffered plate antigen test (BPAT), 99.2% and 99.3% for the standard tube and plate agglutination tests (STAT and SPAT), respectively, and 99.8% for the 2-mercaptoethanol test (2MET). On this small sample, the rose bengal plate test (RBPT), card test (CARD) and the complement fixation test (CFT) correctly classed all sera as negative. On a sample of 167 culture positive cattle, the sensitivities of the tests were CFT: 79.0%, BPAT: 75.4, RBPT: 74.9%, CARD: 74.3%, SPAT: 73.1%, STAT: 68.9%, and 2MET: 59.9%. All tests combined detected only 82% of these infected cattle. Analysis of the relative sensitivity of the six agglutination tests gave the following ranking: BPAT greater than RBPT greater than CARD greater than SPAT greater than STAT. The 2MET ranked between the BPAT and RBPT or between the RBPT and CARD depending on the analysis used. The use of the BPAT as a screening test is recommended provided that a test of high specificity and sensitivity such as the CFT is used to confirm screening test reactions. PMID:4075239

A hybrid Bayesian hierarchical model combining cohort and case-control studies for meta-analysis of diagnostic tests: Accounting for partial verification bias.

PubMed

Ma, Xiaoye; Chen, Yong; Cole, Stephen R; Chu, Haitao

2016-12-01

To account for between-study heterogeneity in meta-analysis of diagnostic accuracy studies, bivariate random effects models have been recommended to jointly model the sensitivities and specificities. As study design and population vary, the definition of disease status or severity could differ across studies. Consequently, sensitivity and specificity may be correlated with disease prevalence. To account for this dependence, a trivariate random effects model had been proposed. However, the proposed approach can only include cohort studies with information estimating study-specific disease prevalence. In addition, some diagnostic accuracy studies only select a subset of samples to be verified by the reference test. It is known that ignoring unverified subjects may lead to partial verification bias in the estimation of prevalence, sensitivities, and specificities in a single study. However, the impact of this bias on a meta-analysis has not been investigated. In this paper, we propose a novel hybrid Bayesian hierarchical model combining cohort and case-control studies and correcting partial verification bias at the same time. We investigate the performance of the proposed methods through a set of simulation studies. Two case studies on assessing the diagnostic accuracy of gadolinium-enhanced magnetic resonance imaging in detecting lymph node metastases and of adrenal fluorine-18 fluorodeoxyglucose positron emission tomography in characterizing adrenal masses are presented. © The Author(s) 2014.

A Hybrid Bayesian Hierarchical Model Combining Cohort and Case-control Studies for Meta-analysis of Diagnostic Tests: Accounting for Partial Verification Bias

PubMed Central

Ma, Xiaoye; Chen, Yong; Cole, Stephen R.; Chu, Haitao

2014-01-01

To account for between-study heterogeneity in meta-analysis of diagnostic accuracy studies, bivariate random effects models have been recommended to jointly model the sensitivities and specificities. As study design and population vary, the definition of disease status or severity could differ across studies. Consequently, sensitivity and specificity may be correlated with disease prevalence. To account for this dependence, a trivariate random effects model had been proposed. However, the proposed approach can only include cohort studies with information estimating study-specific disease prevalence. In addition, some diagnostic accuracy studies only select a subset of samples to be verified by the reference test. It is known that ignoring unverified subjects may lead to partial verification bias in the estimation of prevalence, sensitivities and specificities in a single study. However, the impact of this bias on a meta-analysis has not been investigated. In this paper, we propose a novel hybrid Bayesian hierarchical model combining cohort and case-control studies and correcting partial verification bias at the same time. We investigate the performance of the proposed methods through a set of simulation studies. Two case studies on assessing the diagnostic accuracy of gadolinium-enhanced magnetic resonance imaging in detecting lymph node metastases and of adrenal fluorine-18 fluorodeoxyglucose positron emission tomography in characterizing adrenal masses are presented. PMID:24862512

Functional neuroimaging with default mode network regions distinguishes PTSD from TBI in a military veteran population.

PubMed

Raji, Cyrus A; Willeumier, Kristen; Taylor, Derek; Tarzwell, Robert; Newberg, Andrew; Henderson, Theodore A; Amen, Daniel G

2015-09-01

PTSD and TBI are two common conditions in veteran populations that can be difficult to distinguish clinically. The default mode network (DMN) is abnormal in a multitude of neurological and psychiatric disorders. We hypothesize that brain perfusion SPECT can be applied to diagnostically separate PTSD from TBI reliably in a veteran cohort using DMN regions. A group of 196 veterans (36 with PTSD, 115 with TBI, 45 with PTSD/TBI) were selected from a large multi-site population cohort of individuals with psychiatric disease. Inclusion criteria were peacetime or wartime veterans regardless of branch of service and included those for whom the traumatic brain injury was not service related. SPECT imaging was performed on this group both at rest and during a concentration task. These measures, as well as the baseline-concentration difference, were then inputted from DMN regions into separate binary logistic regression models controlling for age, gender, race, clinic site, co-morbid psychiatric diseases, TBI severity, whether or not the TBI was service related, and branch of armed service. Predicted probabilities were then inputted into a receiver operating characteristic analysis to compute sensitivity, specificity, and accuracy. Compared to PSTD, persons with TBI were older, male, and had higher rates of bipolar and major depressive disorder (p < 0.05). Baseline quantitative regions with SPECT separated PTSD from TBI in the veterans with 92 % sensitivity, 85 % specificity, and 94 % accuracy. With concentration scans, there was 85 % sensitivity, 83 % specificity and 89 % accuracy. Baseline-concentration (the difference metric between the two scans) scans were 85 % sensitivity, 80 % specificity, and 87 % accuracy. In separating TBI from PTSD/TBI visual readings of baseline scans had 85 % sensitivity, 81 % specificity, and 83 % accuracy. Concentration scans had 80 % sensitivity, 65 % specificity, and 79 % accuracy. Baseline-concentration scans had 82 % sensitivity, 69 % specificity, and 81 % accuracy. For separating PTSD from PTSD/TBI baseline scans had 87 % sensitivity, 83 % specificity, and 92 % accuracy. Concentration scans had 91 % sensitivity, 76 % specificity, and 88 % accuracy. Baseline-concentration scans had 84 % sensitivity, 64 % specificity, and 85 % accuracy. This study demonstrates the ability to separate PTSD and TBI from each other in a veteran population using functional neuroimaging.

Sensitivity Analysis for some Water Pollution Problem

NASA Astrophysics Data System (ADS)

Le Dimet, François-Xavier; Tran Thu, Ha; Hussaini, Yousuff

2014-05-01

Sensitivity Analysis for Some Water Pollution Problems Francois-Xavier Le Dimet1 & Tran Thu Ha2 & M. Yousuff Hussaini3 1Université de Grenoble, France, 2Vietnamese Academy of Sciences, 3 Florida State University Sensitivity analysis employs some response function and the variable with respect to which its sensitivity is evaluated. If the state of the system is retrieved through a variational data assimilation process, then the observation appears only in the Optimality System (OS). In many cases, observations have errors and it is important to estimate their impact. Therefore, sensitivity analysis has to be carried out on the OS, and in that sense sensitivity analysis is a second order property. The OS can be considered as a generalized model because it contains all the available information. This presentation proposes a method to carry out sensitivity analysis in general. The method is demonstrated with an application to water pollution problem. The model involves shallow waters equations and an equation for the pollutant concentration. These equations are discretized using a finite volume method. The response function depends on the pollutant source, and its sensitivity with respect to the source term of the pollutant is studied. Specifically, we consider: • Identification of unknown parameters, and • Identification of sources of pollution and sensitivity with respect to the sources. We also use a Singular Evolutive Interpolated Kalman Filter to study this problem. The presentation includes a comparison of the results from these two methods. .

Multiobjective Sensitivity Analysis Of Sediment And Nitrogen Processes With A Watershed Model

EPA Science Inventory

This paper presents a computational analysis for evaluating critical non-point-source sediment and nutrient (specifically nitrogen) processes and management actions at the watershed scale. In the analysis, model parameters that bear key uncertainties were presumed to reflect the ...

Molecular Tools for Diagnosis of Visceral Leishmaniasis: Systematic Review and Meta-Analysis of Diagnostic Test Accuracy

PubMed Central

de Ruiter, C. M.; van der Veer, C.; Leeflang, M. M. G.; Deborggraeve, S.; Lucas, C.

2014-01-01

Molecular methods have been proposed as highly sensitive tools for the detection of Leishmania parasites in visceral leishmaniasis (VL) patients. Here, we evaluate the diagnostic accuracy of these tools in a meta-analysis of the published literature. The selection criteria were original studies that evaluate the sensitivities and specificities of molecular tests for diagnosis of VL, adequate classification of study participants, and the absolute numbers of true positives and negatives derivable from the data presented. Forty studies met the selection criteria, including PCR, real-time PCR, nucleic acid sequence-based amplification (NASBA), and loop-mediated isothermal amplification (LAMP). The sensitivities of the individual studies ranged from 29 to 100%, and the specificities ranged from 25 to 100%. The pooled sensitivity of PCR in whole blood was 93.1% (95% confidence interval [CI], 90.0 to 95.2), and the specificity was 95.6% (95% CI, 87.0 to 98.6). The specificity was significantly lower in consecutive studies, at 63.3% (95% CI, 53.9 to 71.8), due either to true-positive patients not being identified by parasitological methods or to the number of asymptomatic carriers in areas of endemicity. PCR for patients with HIV-VL coinfection showed high diagnostic accuracy in buffy coat and bone marrow, ranging from 93.1 to 96.9%. Molecular tools are highly sensitive assays for Leishmania detection and may contribute as an additional test in the algorithm, together with a clear clinical case definition. We observed wide variety in reference standards and study designs and now recommend consecutively designed studies. PMID:24829226

THE INFLUENCE OF MODEL TIME STEP ON THE RELATIVE SENSITIVITY OF POPULATION GROWTH TO SURVIVAL, GROWTH AND REPRODUCTION

EPA Science Inventory

Matrix population models are often used to extrapolate from life stage-specific stressor effects on survival and reproduction to population-level effects. Demographic elasticity analysis of a matrix model allows an evaluation of the relative sensitivity of population growth rate ...

Bayesian estimation of the sensitivity and specificity of individual fecal culture and Paralisa to detect Mycobacterium avium subspecies paratuberculosis infection in young farmed deer.

PubMed

Stringer, Lesley A; Jones, Geoff; Jewell, Chris P; Noble, Alasdair D; Heuer, Cord; Wilson, Peter R; Johnson, Wesley O

2013-11-01

A Bayesian latent class model was used to estimate the sensitivity and specificity of an immunoglobulin G1 serum enzyme-linked immunosorbent assay (Paralisa) and individual fecal culture to detect young deer infected with Mycobacterium avium subsp. paratuberculosis. Paired fecal and serum samples were collected, between July 2009 and April 2010, from 20 individual yearling (12-24-month-old) deer in each of 20 South Island and 18 North Island herds in New Zealand and subjected to culture and Paralisa, respectively. Two fecal samples and 16 serum samples from 356 North Island deer, and 55 fecal and 37 serum samples from 401 South Island deer, were positive. The estimate of individual fecal culture sensitivity was 77% (95% credible interval [CI] = 61-92%) with specificity of 99% (95% CI = 98-99.7%). The Paralisa sensitivity estimate was 19% (95% CI = 10-30%), with specificity of 94% (95% CI = 93-96%). All estimates were robust to variation of priors and assumptions tested in a sensitivity analysis. The data informs the use of the tests in determining infection status at the individual and herd level.

An alternative respiratory sounds classification system utilizing artificial neural networks.

PubMed

Oweis, Rami J; Abdulhay, Enas W; Khayal, Amer; Awad, Areen

2015-01-01

Computerized lung sound analysis involves recording lung sound via an electronic device, followed by computer analysis and classification based on specific signal characteristics as non-linearity and nonstationarity caused by air turbulence. An automatic analysis is necessary to avoid dependence on expert skills. This work revolves around exploiting autocorrelation in the feature extraction stage. All process stages were implemented in MATLAB. The classification process was performed comparatively using both artificial neural networks (ANNs) and adaptive neuro-fuzzy inference systems (ANFIS) toolboxes. The methods have been applied to 10 different respiratory sounds for classification. The ANN was superior to the ANFIS system and returned superior performance parameters. Its accuracy, specificity, and sensitivity were 98.6%, 100%, and 97.8%, respectively. The obtained parameters showed superiority to many recent approaches. The promising proposed method is an efficient fast tool for the intended purpose as manifested in the performance parameters, specifically, accuracy, specificity, and sensitivity. Furthermore, it may be added that utilizing the autocorrelation function in the feature extraction in such applications results in enhanced performance and avoids undesired computation complexities compared to other techniques.

Novel approach based on one-tube nested PCR and a lateral flow strip for highly sensitive diagnosis of tuberculous meningitis.

PubMed

Sun, Yajuan; Chen, Jiajun; Li, Jia; Xu, Yawei; Jin, Hui; Xu, Na; Yin, Rui; Hu, Guohua

2017-01-01

Rapid and sensitive detection of Mycobacterium tuberculosis (M. Tb) in cerebrospinal fluid is crucial in the diagnosis of tuberculous meningitis (TBM), but conventional diagnostic technologies have limited sensitivity and specificity or are time-consuming. In this work, a novel, highly sensitive molecular diagnostic method, one-tube nested PCR-lateral flow strip test (OTNPCR-LFST), was developed for detecting M. tuberculosis. This one-tube nested PCR maintains the sensitivity of conventional two-step nested PCR and reduces both the chance of cross-contamination and the time required for analysis. The PCR product was detected by a lateral flow strip assay, which provided a basis for migration of the test to a point-of-care (POC) microfluidic format. The developed assay had an improved sensitivity compared with traditional PCR, and the limit of detection was up to 1 fg DNA isolated from M. tuberculosis. The assay was also specific for M. tuberculosis, and no cross-reactions were found in other non-target bacteria. The application of this technique to clinical samples was successfully evaluated, and OTNPCR-LFST showed 89% overall sensitivity and 100% specificity for TBM patients. This one-tube nested PCR-lateral flow strip assay is useful for detecting M. tuberculosis in TBM due to its rapidity, high sensitivity and simple manipulation.

Novel quantitative analysis of autofluorescence images for oral cancer screening.

PubMed

Huang, Tze-Ta; Huang, Jehn-Shyun; Wang, Yen-Yun; Chen, Ken-Chung; Wong, Tung-Yiu; Chen, Yi-Chun; Wu, Che-Wei; Chan, Leong-Perng; Lin, Yi-Chu; Kao, Yu-Hsun; Nioka, Shoko; Yuan, Shyng-Shiou F; Chung, Pau-Choo

2017-05-01

VELscope® was developed to inspect oral mucosa autofluorescence. However, its accuracy is heavily dependent on the examining physician's experience. This study was aimed toward the development of a novel quantitative analysis of autofluorescence images for oral cancer screening. Patients with either oral cancer or precancerous lesions and a control group with normal oral mucosa were enrolled in this study. White light images and VELscope® autofluorescence images of the lesions were taken with a digital camera. The lesion in the image was chosen as the region of interest (ROI). The average intensity and heterogeneity of the ROI were calculated. A quadratic discriminant analysis (QDA) was utilized to compute boundaries based on sensitivity and specificity. 47 oral cancer lesions, 54 precancerous lesions, and 39 normal oral mucosae controls were analyzed. A boundary of specificity of 0.923 and a sensitivity of 0.979 between the oral cancer lesions and normal oral mucosae were validated. The oral cancer and precancerous lesions could also be differentiated from normal oral mucosae with a specificity of 0.923 and a sensitivity of 0.970. The novel quantitative analysis of the intensity and heterogeneity of VELscope® autofluorescence images used in this study in combination with a QDA classifier can be used to differentiate oral cancer and precancerous lesions from normal oral mucosae. Copyright © 2017 Elsevier Ltd. All rights reserved.

Two-step Raman spectroscopy method for tumor diagnosis

NASA Astrophysics Data System (ADS)

Zakharov, V. P.; Bratchenko, I. A.; Kozlov, S. V.; Moryatov, A. A.; Myakinin, O. O.; Artemyev, D. N.

2014-05-01

Two-step Raman spectroscopy phase method was proposed for differential diagnosis of malignant tumor in skin and lung tissue. It includes detection of malignant tumor in healthy tissue on first step with identification of concrete cancer type on the second step. Proposed phase method analyze spectral intensity alteration in 1300-1340 and 1640-1680 cm-1 Raman bands in relation to the intensity of the 1450 cm-1 band on first step, and relative differences between RS intensities for tumor area and healthy skin closely adjacent to the lesion on the second step. It was tested more than 40 ex vivo samples of lung tissue and more than 50 in vivo skin tumors. Linear Discriminant Analysis, Quadratic Discriminant Analysis and Support Vector Machine were used for tumors type classification on phase planes. It is shown that two-step phase method allows to reach 88.9% sensitivity and 87.8% specificity for malignant melanoma diagnosis (skin cancer); 100% sensitivity and 81.5% specificity for adenocarcinoma diagnosis (lung cancer); 90.9% sensitivity and 77.8% specificity for squamous cell carcinoma diagnosis (lung cancer).

Early impairment of somatosensory evoked potentials in very young children with achondroplasia with foramen magnum stenosis.

PubMed

Fornarino, Stefania; Rossi, Daniela Paola; Severino, Mariasavina; Pistorio, Angela; Allegri, Anna Elsa Maria; Martelli, Simona; Doria Lamba, Laura; Lanteri, Paola

2017-02-01

To evaluate the contribution of somatosensory evoked potentials after median nerve (MN-SEPs) and posterior tibial nerve (PTN-SEPs) stimulation in functional assessment of cervical and lumbar spinal stenosis in children with achondroplasia. We reviewed MN-SEPs, PTN-SEPs, and spinal magnetic resonance imaging (MRI) examinations performed in 58 patients with achondroplasia (25 males, 33 females; age range 21d-16y 10mo; mean age 4y 3mo [SD 4y 1mo]). Patients were subdivided into four age categories: <2 years, between 2 to 4 years, between 4 to 8 years, and ≥8 years. The peak latency of P37 for PTN-SEPs, the peak latencies of N11, N13, P14, and N20, and the N13-N20 interpeak latency (IPL) for MN-SEPs were collected; the diagnostic accuracy measures of these parameters (analysis of receiver operating characteristic [ROC] curves) with respect to the presence of foramen magnum or lumbar spinal stenosis were analysed in each age category. The ROC curve analysis showed that the most sensitive parameter in detecting the presence of foramen magnum stenosis was P37 latency in the first two age categories (<2y and ≥2-4y; sensitivity 0.63, specificity 1.00, and sensitivity 1.00, specificity 0.75 respectively). In the third age category (≥4-8y), the most sensitive parameter in detecting the presence of foramen magnum stenosis was IPLs N13-N20 (sensitivity 0.73, specificity 0.87), whereas in the last age category (≥8y), the most important parameter was N20 latency (sensitivity 0.75, specificity 0.77). In children with achondroplasia, the cortical component of PTN-SEPs is more sensitive than the cortical component and central conduction time of MN-SEPs in detection of cervical spinal cord compression at early ages. © 2016 Mac Keith Press.

Interval analysis of interictal EEG: pathology of the alpha rhythm in focal epilepsy

NASA Astrophysics Data System (ADS)

Pyrzowski, Jan; Siemiński, Mariusz; Sarnowska, Anna; Jedrzejczak, Joanna; Nyka, Walenty M.

2015-11-01

The contemporary use of interictal scalp electroencephalography (EEG) in the context of focal epilepsy workup relies on the visual identification of interictal epileptiform discharges. The high-specificity performance of this marker comes, however, at a cost of only moderate sensitivity. Zero-crossing interval analysis is an alternative to Fourier analysis for the assessment of the rhythmic component of EEG signals. We applied this method to standard EEG recordings of 78 patients divided into 4 subgroups: temporal lobe epilepsy (TLE), frontal lobe epilepsy (FLE), psychogenic nonepileptic seizures (PNES) and nonepileptic patients with headache. Interval-analysis based markers were capable of effectively discriminating patients with epilepsy from those in control subgroups (AUC~0.8) with diagnostic sensitivity potentially exceeding that of visual analysis. The identified putative epilepsy-specific markers were sensitive to the properties of the alpha rhythm and displayed weak or non-significant dependences on the number of antiepileptic drugs (AEDs) taken by the patients. Significant AED-related effects were concentrated in the theta interval range and an associated marker allowed for identification of patients on AED polytherapy (AUC~0.9). Interval analysis may thus, in perspective, increase the diagnostic yield of interictal scalp EEG. Our findings point to the possible existence of alpha rhythm abnormalities in patients with epilepsy.

Comparative Diagnostic Performance of Ultrasonography and 99mTc-Sestamibi Scintigraphy for Parathyroid Adenoma in Primary Hyperparathyroidism; Systematic Review and Meta- Analysis

PubMed

Nafisi Moghadam, Reza; Amlelshahbaz, Amir Pasha; Namiranian, Nasim; Sobhan-Ardekani, Mohammad; Emami-Meybodi, Mahmood; Dehghan, Ali; Rahmanian, Masoud; Razavi-Ratki, Seid Kazem

2017-12-28

Objective: Ultrasonography (US) and parathyroid scintigraphy (PS) with 99mTc-MIBI are common methods for preoperative localization of parathyroid adenomas but there discrepancies exist with regard to diagnostic accuracy. The aim of the study was to compare PS and US for localization of parathyroid adenoma with a systematic review and meta-analysis of the literature. Methods: Pub Med, Scopus (EMbase), Web of Science and the reference lists of all included studies were searched up to 1st January 2016. The search strategy was according PICO characteristics. Heterogeneity between the studies was accounted by P < 0.1. Point estimates were pooled estimate of sensitivity, specificity and positive predictive value of SPECT and ultrasonography with 99% confidence intervals (CIs) by pooling available data. Data analysis was performed using Meta-DiSc software (version 1.4). Results: Among 188 studies and after deletion of duplicated studies (75), a total of 113 titles and abstracts were studied. From these, 12 studies were selected. The meta-analysis determined a pooled sensitivity for scintigraphy of 83% [99% confidence interval (CI) 96.358 -97.412] and for ultra-sonography of 80% [99% confidence interval (CI) 76-83]. Similar results for specificity were also obtained for both approache. Conclusion: According this meta- analysis, there were no significant differences between the two methods in terms of sensitivity and specificity. There were overlaps in 99% confidence intervals. Also features of the two methods are similar. Creative Commons Attribution License

The diagnostic performance of shear wave elastography for malignant cervical lymph nodes: A systematic review and meta-analysis.

PubMed

Suh, Chong Hyun; Choi, Young Jun; Baek, Jung Hwan; Lee, Jeong Hyun

2017-01-01

To evaluate the diagnostic performance of shear wave elastography for malignant cervical lymph nodes. We searched the Ovid-MEDLINE and EMBASE databases for published studies regarding the use of shear wave elastography for diagnosing malignant cervical lymph nodes. The diagnostic performance of shear wave elastography was assessed using bivariate modelling and hierarchical summary receiver operating characteristic modelling. Meta-regression analysis and subgroup analysis according to acoustic radiation force impulse imaging (ARFI) and Supersonic shear imaging (SSI) were also performed. Eight eligible studies which included a total sample size of 481 patients with 647 cervical lymph nodes, were included. Shear wave elastography showed a summary sensitivity of 81 % (95 % CI: 72-88 %) and specificity of 85 % (95 % CI: 70-93 %). The results of meta-regression analysis revealed that the prevalence of malignant lymph nodes was a significant factor affecting study heterogeneity (p < .01). According to the subgroup analysis, the summary estimates of the sensitivity and specificity did not differ between ARFI and SSI (p = .93). Shear wave elastography is an acceptable imaging modality for diagnosing malignant cervical lymph nodes. We believe that both ARFI and SSI may have a complementary role for diagnosing malignant cervical lymph nodes. • Shear wave elastography is acceptable modality for diagnosing malignant cervical lymph nodes. • Shear wave elastography demonstrated summary sensitivity of 81 % and specificity of 85 %. • ARFI and SSI have complementary roles for diagnosing malignant cervical lymph nodes.

Obesity in Korean pre-adolescent school children: comparison of various anthropometric measurements based on bioelectrical impedance analysis.

PubMed

Yoo, S; Lee, S-Y; Kim, K-N; Sung, E

2006-07-01

To examine the relationships between body mass index (BMI), percentage-weight-for-height (PWH) and percentage body fat (PBF), and to compare their validity based on PBF with the BMI criteria of International Obesity Task Force (IOTF) for childhood obesity in Korean pre-adolescent school children. Statistical comparative analysis for anthropometric measures. Korean pre-adolescent children (438 boys and 454 girls, aged 8-12 years, mean BMI 19.5+/-3.4 kg/m2). Body mass index and PWH were calculated as body size indices from height and weight. Hand-to-foot bioelectrical impedance analysis (BIA) was performed to obtain PBF values, with obese children defined as PBF above 35%. Sensitivity and specificity were displayed with the gold standard of PBF, and receiver operating characteristic (ROC) curves were used to assess the performance of BMI and PWH in detecting obesity. The prevalence of obesity varied by the criteria: 18.8% by Korean BMI standards for 95 percentile, 11% by the IOTF-BMI 30 kg/m2 and 29.4% by Korean PWH cutoffs. Body mass index and PWH were significantly correlated with PBF after adjusting for age, 0.910 (P<0.01) and 0.915 (P<0.01), respectively. The sensitivity and specificity of the PWH cutoffs were 0.909 and 0.882, respectively. The local BMI 95 percentiles had lower sensitivity (0.714) and specificity (0.790). The IOTF-BMI definition showed much lower sensitivity (0.457) and higher specificity (0.990). The BMI cutoffs corresponding with the highest accuracy were smaller than IOTF-BMI 30 kg/m2 for all age groups in both boys and girls. The prevalence of obesity among Korean pre-adolescent children widely varied according to the diagnostic criteria applied. Universally recommended cutoffs for children by IOTF showed the lowest sensitivity among the criteria used, and may therefore underestimate obesity in this population.

Analysis strategies for high-resolution UHF-fMRI data.

PubMed

Polimeni, Jonathan R; Renvall, Ville; Zaretskaya, Natalia; Fischl, Bruce

2018-03-01

Functional MRI (fMRI) benefits from both increased sensitivity and specificity with increasing magnetic field strength, making it a key application for Ultra-High Field (UHF) MRI scanners. Most UHF-fMRI studies utilize the dramatic increases in sensitivity and specificity to acquire high-resolution data reaching sub-millimeter scales, which enable new classes of experiments to probe the functional organization of the human brain. This review article surveys advanced data analysis strategies developed for high-resolution fMRI at UHF. These include strategies designed to mitigate distortion and artifacts associated with higher fields in ways that attempt to preserve spatial resolution of the fMRI data, as well as recently introduced analysis techniques that are enabled by these extremely high-resolution data. Particular focus is placed on anatomically-informed analyses, including cortical surface-based analysis, which are powerful techniques that can guide each step of the analysis from preprocessing to statistical analysis to interpretation and visualization. New intracortical analysis techniques for laminar and columnar fMRI are also reviewed and discussed. Prospects for single-subject individualized analyses are also presented and discussed. Altogether, there are both specific challenges and opportunities presented by UHF-fMRI, and the use of proper analysis strategies can help these valuable data reach their full potential. Copyright © 2017 Elsevier Inc. All rights reserved.

A Meta-analysis for the Diagnostic Performance of Transient Elastography for Clinically Significant Portal Hypertension.

PubMed

You, Myung-Won; Kim, Kyung Won; Pyo, Junhee; Huh, Jimi; Kim, Hyoung Jung; Lee, So Jung; Park, Seong Ho

2017-01-01

We aimed to evaluate the correlation between liver stiffness measurement using transient elastography (TE-LSM) and hepatic venous pressure gradient and the diagnostic performance of TE-LSM in assessing clinically significant portal hypertension through meta-analysis. Eleven studies were included from thorough literature research and selection processes. The summary correlation coefficient was 0.783 (95% confidence interval [CI], 0.737-0.823). Summary sensitivity, specificity and area under the hierarchical summary receiver operating characteristic curve (AUC) were 87.5% (95% CI, 75.8-93.9%), 85.3 % (95% CI, 76.9-90.9%) and 0.9, respectively. The subgroup with low cut-off values of 13.6-18 kPa had better summary estimates (sensitivity 91.2%, specificity 81.3% and partial AUC 0.921) than the subgroup with high cut-off values of 21-25 kPa (sensitivity 71.2%, specificity 90.9% and partial AUC 0.769). In summary, TE-LSM correlated well with hepatic venous pressure gradient and represented good diagnostic performance in diagnosing clinically significant portal hypertension. For use as a sensitive screening tool, we propose using low cut-off values of 13.6-18 kPa in TE-LSM. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Xpert MTB/RIF Assay for Pulmonary Tuberculosis and Rifampicin Resistance in Children: a Meta-Analysis.

PubMed

Wang, X W; Pappoe, F; Huang, Y; Cheng, X W; Xu, D F; Wang, H; Xu, Y H

2015-01-01

The Xpert MTB/RIF assay has been recommended by WHO to replace conventional microscopy, culture, and drug resistance tests. It simultaneously detects both Mycobacterium tuberculosis infection (TB) and resistance to rifampicin (RIF) within two hours. The objective was to review the available research studies on the accuracy of the Xpert MTB/RIF assay for diagnosing pulmonary TB and RIF-resistance in children. A comprehensive search of Pubmed and Embase was performed up to October 28, 2014. We identified published articles estimating the diagnostic accuracy of the Xpert MTB/RIF assay in children with or without HIV using culture or culture plus clinical TB as standard reference. QUADAS-2 tool was used to evaluate the quality of the studies. A summary estimation for sensitivity, specificity, diagnostic odds ratios (DOR), and the area under the summary ROC curve (AUC) was performed. Meta-analysis was used to establish the overall accuracy. 11 diagnostic studies with 3801 patients were included in the systematic review. The overall analysis revealed a moderate sensitivity and high specificity of 65% (95% CI: 61 - 69%) and 99% (95% CI: 98 - 99%), respectively, and a pooled diagnostic odds ratio of 164.09 (95% CI: 111.89 - 240.64). The AUC value was found to be 0.94. The pooled sensitivity and specificity for paediatric rifampicin resistance were 94.0% (95% CI: 80.0 - 93.0%) and 99.0% (95% CI: 95.0 - 98.0%), respectively. Hence, the Xpert MTB/RIF assay has good diagnostic and rifampicin performance for paediatric pulmonary tuberculosis. The Xpert MTB/RIF is sensitive and specific for diagnosing paediatric pulmonary TB. It is also effective in detecting rifamnicin resistance. It can, therefore, be used as an initial diagnostic tool.

Prediction of the severity of acute pancreatitis on admission by urinary trypsinogen activation peptide: A meta-analysis

PubMed Central

Huang, Wei; Altaf, Kiran; Jin, Tao; Xiong, Jun-Jie; Wen, Li; Javed, Muhammad A; Johnstone, Marianne; Xue, Ping; Halloran, Christopher M; Xia, Qing

2013-01-01

AIM: To undertake a meta-analysis on the value of urinary trypsinogen activation peptide (uTAP) in predicting severity of acute pancreatitis on admission. METHODS: Major databases including Medline, Embase, Science Citation Index Expanded and the Cochrane Central Register of Controlled Trials in the Cochrane Library were searched to identify all relevant studies from January 1990 to January 2013. Pooled sensitivity, specificity and the diagnostic odds ratios (DORs) with 95%CI were calculated for each study and were compared to other systems/biomarkers if mentioned within the same study. Summary receiver-operating curves were conducted and the area under the curve (AUC) was evaluated. RESULTS: In total, six studies of uTAP with a cut-off value of 35 nmol/L were included in this meta-analysis. Overall, the pooled sensitivity and specificity of uTAP for predicting severity of acute pancreatitis, at time of admission, was 71% and 75%, respectively (AUC = 0.83, DOR = 8.67, 95%CI: 3.70-20.33). When uTAP was compared with plasma C-reactive protein, the pooled sensitivity, specificity, AUC and DOR were 0.64 vs 0.67, 0.77 vs 0.75, 0.82 vs 0.79 and 6.27 vs 6.32, respectively. Similarly, the pooled sensitivity, specificity, AUC and DOR of uTAP vs Acute Physiology and Chronic Health Evaluation II within the first 48 h of admission were found to be 0.64 vs 0.69, 0.77 vs 0.61, 0.82 vs 0.73 and 6.27 vs 4.61, respectively. CONCLUSION: uTAP has the potential to act as a stratification marker on admission for differentiating disease severity of acute pancreatitis. PMID:23901239

Whole exome sequencing is an efficient, sensitive and specific method of mutation detection in osteogenesis imperfecta and Marfan syndrome

PubMed Central

McInerney-Leo, Aideen M; Marshall, Mhairi S; Gardiner, Brooke; Coucke, Paul J; Van Laer, Lut; Loeys, Bart L; Summers, Kim M; Symoens, Sofie; West, Jennifer A; West, Malcolm J; Paul Wordsworth, B; Zankl, Andreas; Leo, Paul J; Brown, Matthew A; Duncan, Emma L

2013-01-01

Osteogenesis imperfecta (OI) and Marfan syndrome (MFS) are common Mendelian disorders. Both conditions are usually diagnosed clinically, as genetic testing is expensive due to the size and number of potentially causative genes and mutations. However, genetic testing may benefit patients, at-risk family members and individuals with borderline phenotypes, as well as improving genetic counseling and allowing critical differential diagnoses. We assessed whether whole exome sequencing (WES) is a sensitive method for mutation detection in OI and MFS. WES was performed on genomic DNA from 13 participants with OI and 10 participants with MFS who had known mutations, with exome capture followed by massive parallel sequencing of multiplexed samples. Single nucleotide polymorphisms (SNPs) and small indels were called using Genome Analysis Toolkit (GATK) and annotated with ANNOVAR. CREST, exomeCopy and exomeDepth were used for large deletion detection. Results were compared with the previous data. Specificity was calculated by screening WES data from a control population of 487 individuals for mutations in COL1A1, COL1A2 and FBN1. The target capture of five exome capture platforms was compared. All 13 mutations in the OI cohort and 9/10 in the MFS cohort were detected (sensitivity=95.6%) including non-synonymous SNPs, small indels (<10 bp), and a large UTR5/exon 1 deletion. One mutation was not detected by GATK due to strand bias. Specificity was 99.5%. Capture platforms and analysis programs differed considerably in their ability to detect mutations. Consumable costs for WES were low. WES is an efficient, sensitive, specific and cost-effective method for mutation detection in patients with OI and MFS. Careful selection of platform and analysis programs is necessary to maximize success. PMID:24501682

Immunity to Salmonella typhi: considerations relevant to measurement of cellular immunity in typhoid-endemic regions.

PubMed Central

Murphy, J R; Wasserman, S S; Baqar, S; Schlesinger, L; Ferreccio, C; Lindberg, A A; Levine, M M

1989-01-01

Experiments were performed in Baltimore, Maryland and in Santiago, Chile, to determine the level of Salmonella typhi antigen-driven in vitro lymphocyte replication response which signifies specific acquired immunity to this bacterium and to determine the best method of data analysis and form of data presentation. Lymphocyte replication was measured as incorporation of 3H-thymidine into desoxyribonucleic acid. Data (ct/min/culture) were analyzed in raw form and following log transformation, by non-parametric and parametric statistical procedures. A preference was developed for log-transformed data and discriminant analysis. Discriminant analysis of log-transformed data revealed 3H-thymidine incorporation rates greater than 3,433 for particulate S. typhi, Ty2 antigen stimulated cultures signified acquired immunity at a sensitivity and specificity of 82.7; for soluble S. typhi O polysaccharide antigen-stimulated cultures, ct/min/culture values of greater than 1,237 signified immunity (sensitivity and specificity 70.5%). PMID:2702777

Wavenumber selection based analysis in Raman spectroscopy improves skin cancer diagnostic specificity at high sensitivity levels (Conference Presentation)

NASA Astrophysics Data System (ADS)

Zhao, Jianhua; Zeng, Haishan; Kalia, Sunil; Lui, Harvey

2017-02-01

Background: Raman spectroscopy is a non-invasive optical technique which can measure molecular vibrational modes within tissue. A large-scale clinical study (n = 518) has demonstrated that real-time Raman spectroscopy could distinguish malignant from benign skin lesions with good diagnostic accuracy; this was validated by a follow-up independent study (n = 127). Objective: Most of the previous diagnostic algorithms have typically been based on analyzing the full band of the Raman spectra, either in the fingerprint or high wavenumber regions. Our objective in this presentation is to explore wavenumber selection based analysis in Raman spectroscopy for skin cancer diagnosis. Methods: A wavenumber selection algorithm was implemented using variably-sized wavenumber windows, which were determined by the correlation coefficient between wavenumbers. Wavenumber windows were chosen based on accumulated frequency from leave-one-out cross-validated stepwise regression or least and shrinkage selection operator (LASSO). The diagnostic algorithms were then generated from the selected wavenumber windows using multivariate statistical analyses, including principal component and general discriminant analysis (PC-GDA) and partial least squares (PLS). A total cohort of 645 confirmed lesions from 573 patients encompassing skin cancers, precancers and benign skin lesions were included. Lesion measurements were divided into training cohort (n = 518) and testing cohort (n = 127) according to the measurement time. Result: The area under the receiver operating characteristic curve (ROC) improved from 0.861-0.891 to 0.891-0.911 and the diagnostic specificity for sensitivity levels of 0.99-0.90 increased respectively from 0.17-0.65 to 0.20-0.75 by selecting specific wavenumber windows for analysis. Conclusion: Wavenumber selection based analysis in Raman spectroscopy improves skin cancer diagnostic specificity at high sensitivity levels.

Ultrasensitive and Multiple Disease-Related MicroRNA Detection Based on Tetrahedral DNA Nanostructures and Duplex-Specific Nuclease-Assisted Signal Amplification.

PubMed

Xu, Fang; Dong, Haifeng; Cao, Yu; Lu, Huiting; Meng, Xiangdan; Dai, Wenhao; Zhang, Xueji; Al-Ghanim, Khalid Abdullah; Mahboob, Shahid

2016-12-14

A highly sensitive and multiple microRNA (miRNA) detection method by combining three-dimensional (3D) DNA tetrahedron-structured probes (TSPs) to increase the probe reactivity and accessibility with duplex-specific nuclease (DSN) for signal amplification for sensitive miRNA detection was proposed. Briefly, 3D DNA TSPs labeled with different fluorescent dyes for specific target miRNA recognition were modified on a gold nanoparticle (GNP) surface to increase the reactivity and accessibility. Upon hybridization with a specific target, the TSPs immobilized on the GNP surface hybridized with the corresponding target miRNA to form DNA-RNA heteroduplexes, and the DSN can recognize the formed DNA-RNA heteroduplexes to hydrolyze the DNA in the heteroduplexes to produce a specific fluorescent signal corresponding to a specific miRNA, while the released target miRNA strands can initiate another cycle, resulting in a significant signal amplification for sensitive miRNA detection. Different targets can produce different fluorescent signals, leading to the development of a sensitive detection for multiple miRNAs in a homogeneous solution. Under optimized conditions, the proposed assay can simultaneously detect three different miRNAs in a homogeneous solution with a logarithmic linear range spanning 5 magnitudes (10 -12 -10 -16 ) and achieving a limit of detection down to attomolar concentrations. Meanwhile, the proposed miRNA assay exhibited the capability of discriminating single bases (three bases mismatched miRNAs) and showed good eligibility in the analysis of miRNAs extracted from cell lysates and miRNAs in cell incubation media, which indicates its potential use in biomedical research and clinical analysis.

A Global Sensitivity Analysis Method on Maximum Tsunami Wave Heights to Potential Seismic Source Parameters

NASA Astrophysics Data System (ADS)

Ren, Luchuan

2015-04-01

A Global Sensitivity Analysis Method on Maximum Tsunami Wave Heights to Potential Seismic Source Parameters Luchuan Ren, Jianwei Tian, Mingli Hong Institute of Disaster Prevention, Sanhe, Heibei Province, 065201, P.R. China It is obvious that the uncertainties of the maximum tsunami wave heights in offshore area are partly from uncertainties of the potential seismic tsunami source parameters. A global sensitivity analysis method on the maximum tsunami wave heights to the potential seismic source parameters is put forward in this paper. The tsunami wave heights are calculated by COMCOT ( the Cornell Multi-grid Coupled Tsunami Model), on the assumption that an earthquake with magnitude MW8.0 occurred at the northern fault segment along the Manila Trench and triggered a tsunami in the South China Sea. We select the simulated results of maximum tsunami wave heights at specific sites in offshore area to verify the validity of the method proposed in this paper. For ranking importance order of the uncertainties of potential seismic source parameters (the earthquake's magnitude, the focal depth, the strike angle, dip angle and slip angle etc..) in generating uncertainties of the maximum tsunami wave heights, we chose Morris method to analyze the sensitivity of the maximum tsunami wave heights to the aforementioned parameters, and give several qualitative descriptions of nonlinear or linear effects of them on the maximum tsunami wave heights. We quantitatively analyze the sensitivity of the maximum tsunami wave heights to these parameters and the interaction effects among these parameters on the maximum tsunami wave heights by means of the extended FAST method afterward. The results shows that the maximum tsunami wave heights are very sensitive to the earthquake magnitude, followed successively by the epicenter location, the strike angle and dip angle, the interactions effect between the sensitive parameters are very obvious at specific site in offshore area, and there exist differences in importance order in generating uncertainties of the maximum tsunami wave heights for same group parameters at different specific sites in offshore area. These results are helpful to deeply understand the relationship between the tsunami wave heights and the seismic tsunami source parameters. Keywords: Global sensitivity analysis; Tsunami wave height; Potential seismic tsunami source parameter; Morris method; Extended FAST method

Methylated site display (MSD)-AFLP, a sensitive and affordable method for analysis of CpG methylation profiles.

PubMed

Aiba, Toshiki; Saito, Toshiyuki; Hayashi, Akiko; Sato, Shinji; Yunokawa, Harunobu; Maruyama, Toru; Fujibuchi, Wataru; Kurita, Hisaka; Tohyama, Chiharu; Ohsako, Seiichiroh

2017-03-09

It has been pointed out that environmental factors or chemicals can cause diseases that are developmental in origin. To detect abnormal epigenetic alterations in DNA methylation, convenient and cost-effective methods are required for such research, in which multiple samples are processed simultaneously. We here present methylated site display (MSD), a unique technique for the preparation of DNA libraries. By combining it with amplified fragment length polymorphism (AFLP) analysis, we developed a new method, MSD-AFLP. Methylated site display libraries consist of only DNAs derived from DNA fragments that are CpG methylated at the 5' end in the original genomic DNA sample. To test the effectiveness of this method, CpG methylation levels in liver, kidney, and hippocampal tissues of mice were compared to examine if MSD-AFLP can detect subtle differences in the levels of tissue-specific differentially methylated CpGs. As a result, many CpG sites suspected to be tissue-specific differentially methylated were detected. Nucleotide sequences adjacent to these methyl-CpG sites were identified and we determined the methylation level by methylation-sensitive restriction endonuclease (MSRE)-PCR analysis to confirm the accuracy of AFLP analysis. The differences of the methylation level among tissues were almost identical among these methods. By MSD-AFLP analysis, we detected many CpGs showing less than 5% statistically significant tissue-specific difference and less than 10% degree of variability. Additionally, MSD-AFLP analysis could be used to identify CpG methylation sites in other organisms including humans. MSD-AFLP analysis can potentially be used to measure slight changes in CpG methylation level. Regarding the remarkable precision, sensitivity, and throughput of MSD-AFLP analysis studies, this method will be advantageous in a variety of epigenetics-based research.

Role of androgen ratios in the prediction of the metabolic phenotype in polycystic ovary syndrome.

PubMed

Minooee, Sonia; Ramezani Tehrani, Fahimeh; Tohidi, Maryam; Azizi, Fereidoun

2017-05-01

To identify the androgen ratio that best predicts insulin resistance and metabolic syndrome among women with polycystic ovary syndrome (PCOS). Data for 180 women with PCOS and 180 healthy controls were extracted from two previous studies in Iran (conducted during 2008-2010 and 2011-2013). The diagnosis of PCOS was based on the Rotterdam criteria. The serum concentration of different androgens was measured. Receiver operating characteristic curve analysis was used to assess the ability of various androgen ratios to predict insulin resistance and metabolic syndrome. Among women with PCOS, the testosterone-to-androstenedione ratio was the best predictor of insulin resistance (sensitivity 0.83, specificity 0.42) and metabolic syndrome (sensitivity 0.85, specificity 0.70). Among healthy controls, the ratio of free androgen index to testosterone was the best predictor of insulin resistance (sensitivity 0.84, specificity 0.33) and metabolic syndrome (sensitivity 0.91, specificity 0.17). The prediction of insulin resistance and metabolic syndrome among women with PCOS was best accomplished with the testosterone-to-androstenedione ratio. © 2017 International Federation of Gynecology and Obstetrics.

Sensitivity of Forecast Skill to Different Objective Analysis Schemes

NASA Technical Reports Server (NTRS)

Baker, W. E.

1979-01-01

Numerical weather forecasts are characterized by rapidly declining skill in the first 48 to 72 h. Recent estimates of the sources of forecast error indicate that the inaccurate specification of the initial conditions contributes substantially to this error. The sensitivity of the forecast skill to the initial conditions is examined by comparing a set of real-data experiments whose initial data were obtained with two different analysis schemes. Results are presented to emphasize the importance of the objective analysis techniques used in the assimilation of observational data.

DNA Methylation Analysis of the SHOX2 and RASSF1A Panel in Bronchoalveolar Lavage Fluid for Lung Cancer Diagnosis

PubMed Central

Zhang, Chenzi; Yu, Wenjun; Wang, Lin; Zhao, Mingna; Guo, Qiaomei; Lv, Shaogang; Hu, Xiaomeng; Lou, Jiatao

2017-01-01

Introduction: Currently the majority of lung cancer patients are diagnosed as advanced diseases for no sensitive and specific biomarkers exist, noninvasive biomarkers with high sensitivity and specificity are urgently needed in lung cancer diagnosis. Bronchoscopy is a standard procedure of the diagnostic work-up of patients with suspected lung cancer despite of the limited diagnostic accuracy. Besides, epigenetic changes through DNA methylation play an important role in tumorigenesis. Thus, we examined the aberrant methylation of the SHOX2 and RASSF1A in bronchoalveolar lavage fluid (BALF) in comparing with conventional cytology examination and serum CEA in order to evaluate the new diagnostic method. Patients and Methods: BALF and serum samples were collected from 322 patients at the time of diagnosis, 284 of them were pathologically confirmed lung cancer, 35 were benign lung diseases and 3 were malignancies in other systems. For all of the 322 patients, the methylation status of the SHOX2 and RASSF1A gene were detected by a new RT-PCR platform and then confirmed by sanger sequencing. Serum CEA were detected using electrochemiluminescence immunoassay. Results: Profiling data showed the consistency of RT-PCR and sanger sequencing in detecting the methylation of the SHOX2 and RASSF1A. Besides, the combination of SHOX2 and RASSF1A methylation in BALF yielded a diagnostic sensitivity of 81.0% and specificity of 97.4%. When compared with established cytology examination (sensitivity: 68.3%, specificity: 97.4%) and serum biomarker carcinoembryonic antigen (CEA) (sensitivity: 30.6%, specificity: 100.0%), the SHOX2 and RASSF1A methylation panel showed the highest diagnostic efficiency. Notably, the combination of cytology and the SHOX2 and RASSF1A methylation panel could significantly improve the diagnostic efficacy. Conclusion: The methylation analysis of the SHOX2 and RASSF1A panel in BALF with RT-PCR achieved a satisfactory sensitivity and specificity in lung cancer diagnosis, especially in an early stage. It could be used as a promising noninvasive biomarker for auxiliary diagnosis of lung cancer. PMID:29151944

Evaluation of Visual Field and Imaging Outcomes for Glaucoma Clinical Trials (An American Ophthalomological Society Thesis).

PubMed

Garway-Heath, David F; Quartilho, Ana; Prah, Philip; Crabb, David P; Cheng, Qian; Zhu, Haogang

2017-08-01

To evaluate the ability of various visual field (VF) analysis methods to discriminate treatment groups in glaucoma clinical trials and establish the value of time-domain optical coherence tomography (TD OCT) imaging as an additional outcome. VFs and retinal nerve fibre layer thickness (RNFLT) measurements (acquired by TD OCT) from 373 glaucoma patients in the UK Glaucoma Treatment Study (UKGTS) at up to 11 scheduled visits over a 2 year interval formed the cohort to assess the sensitivity of progression analysis methods. Specificity was assessed in 78 glaucoma patients with up to 11 repeated VF and OCT RNFLT measurements over a 3 month interval. Growth curve models assessed the difference in VF and RNFLT rate of change between treatment groups. Incident progression was identified by 3 VF-based methods: Guided Progression Analysis (GPA), 'ANSWERS' and 'PoPLR', and one based on VFs and RNFLT: 'sANSWERS'. Sensitivity, specificity and discrimination between treatment groups were evaluated. The rate of VF change was significantly faster in the placebo, compared to active treatment, group (-0.29 vs +0.03 dB/year, P <.001); the rate of RNFLT change was not different (-1.7 vs -1.1 dB/year, P =.14). After 18 months and at 95% specificity, the sensitivity of ANSWERS and PoPLR was similar (35%); sANSWERS achieved a sensitivity of 70%. GPA, ANSWERS and PoPLR discriminated treatment groups with similar statistical significance; sANSWERS did not discriminate treatment groups. Although the VF progression-detection method including VF and RNFLT measurements is more sensitive, it does not improve discrimination between treatment arms.

Latent class analysis reveals clinically relevant atopy phenotypes in 2 birth cohorts.

PubMed

Hose, Alexander J; Depner, Martin; Illi, Sabina; Lau, Susanne; Keil, Thomas; Wahn, Ulrich; Fuchs, Oliver; Pfefferle, Petra Ina; Schmaußer-Hechfellner, Elisabeth; Genuneit, Jon; Lauener, Roger; Karvonen, Anne M; Roduit, Caroline; Dalphin, Jean-Charles; Riedler, Josef; Pekkanen, Juha; von Mutius, Erika; Ege, Markus J

2017-06-01

Phenotypes of childhood-onset asthma are characterized by distinct trajectories and functional features. For atopy, definition of phenotypes during childhood is less clear. We sought to define phenotypes of atopic sensitization over the first 6 years of life using a latent class analysis (LCA) integrating 3 dimensions of atopy: allergen specificity, time course, and levels of specific IgE (sIgE). Phenotypes were defined by means of LCA in 680 children of the Multizentrische Allergiestudie (MAS) and 766 children of the Protection against allergy: Study in Rural Environments (PASTURE) birth cohorts and compared with classical nondisjunctive definitions of seasonal, perennial, and food sensitization with respect to atopic diseases and lung function. Cytokine levels were measured in the PASTURE cohort. The LCA classified predominantly by type and multiplicity of sensitization (food vs inhalant), allergen combinations, and sIgE levels. Latent classes were related to atopic disease manifestations with higher sensitivity and specificity than the classical definitions. LCA detected consistently in both cohorts a distinct group of children with severe atopy characterized by high seasonal sIgE levels and a strong propensity for asthma; hay fever; eczema; and impaired lung function, also in children without an established asthma diagnosis. Severe atopy was associated with an increased IL-5/IFN-γ ratio. A path analysis among sensitized children revealed that among all features of severe atopy, only excessive sIgE production early in life affected asthma risk. LCA revealed a set of benign, symptomatic, and severe atopy phenotypes. The severe phenotype emerged as a latent condition with signs of a dysbalanced immune response. It determined high asthma risk through excessive sIgE production and directly affected impaired lung function. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Cutoff values for bacteria and leukocytes for urine sediment analyzer FUS200 in culture-positive urinary-tract infections.

PubMed

Kocer, Derya; Sarıguzel, Fatma M; Karakukcu, Cıgdem

2014-08-01

The microscopic analysis of urine is essential for the diagnosis of patients with urinary tract infections. Quantitative urine culture is the 'gold standard' method for definitive diagnosis of urinary-tract infections, but it is labor-intensive, time consuming, and does not provide the same-day results. The aim of this study was to evaluate the analytical and diagnostic performance of the FUS200 (Changchun Dirui Industry, China), a new urine sedimentation analyzer in comparison to urine culture as the reference method. We evaluated 1000 urine samples, submitted for culture and urine analysis with a preliminary diagnosis of urinary-tract infection. Cut-off values for the FUS200 were determined by comparing the results with urine cultures. The cut-off values by the receiver operating characteristic (ROC) curve technique, sensitivity, and specificity were calculated for bacteria and white blood cells (WBCs). Among the 1000 urine specimens submitted for culture, 637 cultures (63.7%) were negative, and 363 were (36.3%) positive. The best cut-off values obtained from ROC analysis were 16/μL for bacteriuria (sensitivity: 82.3%, specificity: 58%), and 34/μL for WBCs (sensitivity: 72.3%, specificity: 65.2%). The area under the curve (AUC) for the bacteria and WBCs count were 0.71 (95% CI: 0.67-0.74) and, 0.72 (95% CI: 0.69-0.76) respectively. The most important requirement of a rapid diagnostic screening test is sensitivity, and, in this perspective, an unsatisfactory sensitivity by using bacteria recognition and quantification performed by the FUS200 analyzer has been observed. After further technical improvements in particle recognition and laboratory personnel training, the FUS200 might show better results.

Meta-Analysis of Predictive Significance of the Black Hole Sign for Hematoma Expansion in Intracerebral Hemorrhage.

PubMed

Zheng, Jun; Yu, Zhiyuan; Guo, Rui; Li, Hao; You, Chao; Ma, Lu

2018-04-27

Hematoma expansion is related to unfavorable prognosis in intracerebral hemorrhage (ICH). The black hole sign is a novel marker on non-contrast computed tomography for predicting hematoma expansion. However, its predictive values are different in previous studies. Thus, this meta-analysis was conducted to evaluate the predictive significance of the black hole sign for hematoma expansion in ICH. A systematic literature search was performed. Original researches on the association between the black hole sign and hematoma expansion in ICH were included. Sensitivity and specificity were pooled to assess the predictive accuracy. Summary receiver operating characteristics curve (SROC) was developed. Deeks' funnel plot asymmetry test was used to assess the publication bias. Five studies with a total of 1495 patients were included in this study. The pooled sensitivity and specificity of the black hole sign for predicting hematoma expansion were 0.30 and 0.91, respectively. The area under the curve was 0.78 in SROC curve. There was no significant publication bias. This meta-analysis shows that the black hole sign is a helpful imaging marker for predicting hematoma expansion in ICH. Although the black hole sign has a relatively low sensitivity, its specificity is relatively high. Copyright © 2018 Elsevier Inc. All rights reserved.

Hierarchical Nanogold Labels to Improve the Sensitivity of Lateral Flow Immunoassay

NASA Astrophysics Data System (ADS)

Serebrennikova, Kseniya; Samsonova, Jeanne; Osipov, Alexander

2018-06-01

Lateral flow immunoassay (LFIA) is a widely used express method and offers advantages such as a short analysis time, simplicity of testing and result evaluation. However, an LFIA based on gold nanospheres lacks the desired sensitivity, thereby limiting its wide applications. In this study, spherical nanogold labels along with new types of nanogold labels such as gold nanopopcorns and nanostars were prepared, characterized, and applied for LFIA of model protein antigen procalcitonin. It was found that the label with a structure close to spherical provided more uniform distribution of specific antibodies on its surface, indicative of its suitability for this type of analysis. LFIA using gold nanopopcorns as a label allowed procalcitonin detection over a linear range of 0.5-10 ng mL-1 with the limit of detection of 0.1 ng mL-1, which was fivefold higher than the sensitivity of the assay with gold nanospheres. Another approach to improve the sensitivity of the assay included the silver enhancement method, which was used to compare the amplification of LFIA for procalcitonin detection. The sensitivity of procalcitonin determination by this method was 10 times better the sensitivity of the conventional LFIA with gold nanosphere as a label. The proposed approach of LFIA based on gold nanopopcorns improved the detection sensitivity without additional steps and prevented the increased consumption of specific reagents (antibodies).

Meta-analysis of the relative sensitivity of semi-natural vegetation species to ozone.

PubMed

Hayes, F; Jones, M L M; Mills, G; Ashmore, M

2007-04-01

This study identified 83 species from existing publications suitable for inclusion in a database of sensitivity of species to ozone (OZOVEG database). An index, the relative sensitivity to ozone, was calculated for each species based on changes in biomass in order to test for species traits associated with ozone sensitivity. Meta-analysis of the ozone sensitivity data showed a wide inter-specific range in response to ozone. Some relationships in comparison to plant physiological and ecological characteristics were identified. Plants of the therophyte lifeform were particularly sensitive to ozone. Species with higher mature leaf N concentration were more sensitive to ozone than those with lower leaf N concentration. Some relationships between relative sensitivity to ozone and Ellenberg habitat requirements were also identified. In contrast, no relationships between relative sensitivity to ozone and mature leaf P concentration, Grime's CSR strategy, leaf longevity, flowering season, stomatal density and maximum altitude were found. The relative sensitivity of species and relationships with plant characteristics identified in this study could be used to predict sensitivity to ozone of untested species and communities.

Necrotizing Soft Tissue Infection: Diagnostic Accuracy of Physical Examination, Imaging, and LRINEC Score: A Systematic Review and Meta-Analysis.

PubMed

Fernando, Shannon M; Tran, Alexandre; Cheng, Wei; Rochwerg, Bram; Kyeremanteng, Kwadwo; Seely, Andrew J E; Inaba, Kenji; Perry, Jeffrey J

2018-04-18

We sought to summarize accuracy of physical examination, imaging, and Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) score in diagnosis of necrotizing soft tissue infection (NSTI) in adults with a soft tissue infection clinically concerning for NSTI. NSTI is a life-threatening diagnosis. Delay to diagnosis and surgical management is associated with increased mortality. We searched 6 databases from inception through November 2017. We included English-language studies reporting diagnostic accuracy of testing or LRINEC Score. Outcome was NSTI confirmed by surgery or histopathology. Two reviewers screened all citations and extracted data independently. Summary measures were obtained from the Hierarchical Summary Receiver Operating Characteristic model. From 2,290 citations, we included 23 studies (n = 5982). Of physical examination signs, pooled sensitivity and specificity for fever was 46.0% and 77.0% respectively, for hemorrhagic bullae 25.2% and 95.8%, and for hypotension 21.0% and 97.7%. Computed tomography (CT) had sensitivity of 88.5% and specificity of 93.3%, while plain radiography had sensitivity of 48.9% and specificity of 94.0%. Finally, LRINEC ≥ 6 had sensitivity of 68.2% and specificity of 84.8%, while LRINEC ≥ 8 had sensitivity of 40.8% and specificity of 94.9%. Absence of any 1 physical examination feature (eg, fever or hypotension) is not sufficient to rule-out NSTI. CT is superior to plain radiography. LRINEC had poor sensitivity, and should not be used to rule-out NSTI. Given the poor sensitivity of these tests, a high clinical suspicion warrants early surgical consultation for definitive diagnosis and management.

Validity, sensitivity and specificity of the mentation, behavior and mood subscale of the UPDRS.

PubMed

Holroyd, Suzanne; Currie, Lillian J; Wooten, G Frederick

2008-06-01

The unified Parkinson's disease rating scale (UPDRS) is the most widely used tool to rate the severity and the stage of Parkinson's disease (PD). However, the mentation, behavior and mood (MBM) subscale of the UPDRS has received little investigation regarding its validity and sensitivity. Three items of this subscale were compared to criterion tests to examine validity, sensitivity and specificity. Ninety-seven patients with idiopathic PD were assessed on the UPDRS. Scores on three items of the MBM subscale, intellectual impairment, thought disorder and depression, were compared to criterion tests, the telephone interview for cognition status (TICS), psychiatric assessment for psychosis and the geriatric depression scale (GDS). Non-parametric tests of association were performed to examine concurrent validity of the MBM items. The sensitivities, specificities and optimal cutoff scores for each MBM item were estimated by receiver operating characteristic (ROC) curve analysis. The MBM items demonstrated low to moderate correlation with the criterion tests, and the sensitivity and specificity were not strong. Even using a score of 7.0 on the items of the MBM demonstrated a sensitivity/specificity of only 0.19/0.48 for intellectual impairment, 0.60/0.72 for thought disorder and 0.61/0.87 for depression. Using a more appropriate cutoff of 2.0 revealed sensitivities of 0.01, 0.38 and 0.13 respectively. The MBM subscale items of intellectual impairment, thought disorder and depression are not appropriate for screening or diagnostic purposes. Tools such as the TICS and the GDS should be considered instead.

Reliability, validity, sensitivity and specificity of Guajarati version of the Roland-Morris Disability Questionnaire.

PubMed

Nambi, S Gopal

2013-01-01

The most common instruments developed to assess the functional status of patients with Non specific low back pain is the Roland-Morris Disability Questionnaire (RMDQ). Clinical and epidemiological research related to low back pain in the Gujarati population would be facilitated by the availability of well-established outcome measures. To find the reliability, validity, sensitivity and specificity of the Gujarati version of the RMDQ for use in Non Specific Chronic low back pain. A reliability, validity, sensitivity and specificity study of Gujarati version of the Roland-Morris Disability Questionnaire (RMDQ). Thirty out patients with Non Specific Chronic low back pain were assessed by the RMDQ. Reliability is assessed by using internal consistency and the intra-class correlation coefficient (ICC). Internal construct validity is assessed by RASCH Analysis and external construct validity is assessed by association with pain and spinal movement. Clinical calculator was used to determine the sensitivity and specificity. Internal consistency of the RMDQ is found to be adequate (> 0.65) at both times, with high ICC's also at both time points. Internal construct validity of the scale is good, indicating a single underlying construct. Expected associations with pain and spinal movement confirm external construct validity. The Sensitivity and Specificity at cut off point of 0.5 was 80% and 84% with respectively positive predictive value (PPV) of 83.33% and negative predictive value (NPV) of 80.76%. The Questionnaire is at the ordinal level. The RMDQ is a one-dimensional, ordinal measure, which works well in the Gujarati population.

Validity of Heart Failure Diagnoses in Administrative Databases: A Systematic Review and Meta-Analysis

PubMed Central

McCormick, Natalie; Lacaille, Diane; Bhole, Vidula; Avina-Zubieta, J. Antonio

2014-01-01

Objective Heart failure (HF) is an important covariate and outcome in studies of elderly populations and cardiovascular disease cohorts, among others. Administrative data is increasingly being used for long-term clinical research in these populations. We aimed to conduct the first systematic review and meta-analysis of studies reporting on the validity of diagnostic codes for identifying HF in administrative data. Methods MEDLINE and EMBASE were searched (inception to November 2010) for studies: (a) Using administrative data to identify HF; or (b) Evaluating the validity of HF codes in administrative data; and (c) Reporting validation statistics (sensitivity, specificity, positive predictive value [PPV], negative predictive value, or Kappa scores) for HF, or data sufficient for their calculation. Additional articles were located by hand search (up to February 2011) of original papers. Data were extracted by two independent reviewers; article quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool. Using a random-effects model, pooled sensitivity and specificity values were produced, along with estimates of the positive (LR+) and negative (LR−) likelihood ratios, and diagnostic odds ratios (DOR = LR+/LR−) of HF codes. Results Nineteen studies published from1999–2009 were included in the qualitative review. Specificity was ≥95% in all studies and PPV was ≥87% in the majority, but sensitivity was lower (≥69% in ≥50% of studies). In a meta-analysis of the 11 studies reporting sensitivity and specificity values, the pooled sensitivity was 75.3% (95% CI: 74.7–75.9) and specificity was 96.8% (95% CI: 96.8–96.9). The pooled LR+ was 51.9 (20.5–131.6), the LR− was 0.27 (0.20–0.37), and the DOR was 186.5 (96.8–359.2). Conclusions While most HF diagnoses in administrative databases do correspond to true HF cases, about one-quarter of HF cases are not captured. The use of broader search parameters, along with laboratory and prescription medication data, may help identify more cases. PMID:25126761

64 slice-coronary computed tomography sensitivity and specificity in the evaluation of coronary artery bypass graft stenosis: A meta-analysis.

PubMed

Barbero, Umberto; Iannaccone, Mario; d'Ascenzo, Fabrizio; Barbero, Cristina; Mohamed, Abdirashid; Annone, Umberto; Benedetto, Sara; Celentani, Dario; Gagliardi, Marco; Moretti, Claudio; Gaita, Fiorenzo

2016-08-01

A non-invasive approach to define grafts patency and stenosis in the follow-up of coronary artery bypass graft (CABG) patients may be an interesting alternative to coronary angiography. 64-slice-coronary computed tomography is nowadays a diffused non-invasive method that permits an accurate evaluation of coronary stenosis, due to a high temporal and spatial resolution. However, its sensitivity and specificity in CABG evaluation has to be clearly defined, since published studies used different protocols and scanners. We collected all studies investigating patients with stable symptoms and previous CABG and reporting the comparison between diagnostic performances of invasive coronary angiography and 64-slice-coronary computed tomography. As a result, sensitivity and specificity of 64-slice-coronary computed tomography for CABG occlusion were 0.99 (95% CI 0.97-1.00) and 0.99 (95% CI: 0.99-1.00) with an area under the curve (AUC) of 0.99. 64-slice-coronary computed tomography sensitivity and specificity for the presence of any CABG stenosis >50% were 0.98 (95% CI: 0.97-0.99) and 0.98 (95% CI: 0.96-0.98), while AUC was 0.99. At meta-regression, neither the age nor the time from graft implantation had effect on sensitivity and specificity of 64-slice-coronary computed tomography detection of significant CABG stenosis or occlusion. In conclusion 64-slice-coronary computed tomography confirmed its high sensitivity and specificity in CABG stenosis or occlusion evaluation. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

IgE sensitization in relation to preschool eczema and filaggrin mutation.

PubMed

Johansson, Emma Kristin; Bergström, Anna; Kull, Inger; Lind, Tomas; Söderhäll, Cilla; van Hage, Marianne; Wickman, Magnus; Ballardini, Natalia; Wahlgren, Carl-Fredrik

2017-12-01

Eczema (atopic dermatitis) is associated with an increased risk of having IgE antibodies. IgE sensitization can occur through an impaired skin barrier. Filaggrin gene (FLG) mutation is associated with eczema and possibly also with IgE sensitization. We sought to explore the longitudinal relation between preschool eczema (PSE), FLG mutation, or both and IgE sensitization in childhood. A total of 3201 children from the BAMSE (Children Allergy Milieu Stockholm Epidemiology) birth cohort recruited from the general population were included. Regular parental questionnaires identified children with eczema. Blood samples were collected at 4, 8, and 16 years of age for analysis of specific IgE. FLG mutation analysis was performed on 1890 of the children. PSE was associated with IgE sensitization to both food allergens and aeroallergens up to age 16 years (overall adjusted odds ratio, 2.30; 95% CI, 2.00-2.66). This association was even stronger among children with persistent PSE. FLG mutation was associated with IgE sensitization to peanut at age 4 years (adjusted odds ratio, 1.88; 95% CI, 1.03-3.44) but not to other allergens up to age 16 years. FLG mutation and PSE were not effect modifiers for the association between IgE sensitization and PSE or FLG mutation, respectively. Sensitized children with PSE were characterized by means of polysensitization, but no other specific IgE sensitization patterns were found. PSE is associated with IgE sensitization to both food allergens and aeroallergens up to 16 years of age. FLG mutation is associated with IgE sensitization to peanut but not to other allergens. Sensitized children with preceding PSE are more often polysensitized. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

HLA-typing analysis following allogeneic bone grafting for sinus lifting.

PubMed

Piaia, Marcelo; Bub, Carolina Bonet; Succi, Guilherme de Menezes; Torres, Margareth; Costa, Thiago Henrique; Pinheiro, Fabricio Costa; Napimoga, Marcelo Henrique

2017-03-01

According to the Brazilian Association of Organ Transplants, in 2015, 19,408 bone transplants were performed in Brazil, over 90% by Dental Surgeons. The surgical technique itself has a respectable number of reports regarding its clinical efficacy, as measured by long-term survival of dental implants in grafted areas. Uncertainty remains, however, as to whether fresh frozen grafts from human bone donors remain immunologically innocuous in the body of the host. Six male with no previous medical history of note, including systemic diseases, surgery or blood transfusion were selected. These patients underwent reconstructive procedures (sinus lifting) using fresh frozen human bone from a tissue bank. All patients had venous blood samples collected prior to surgery and 6 months after the procedure. Anti-HLA analysis for the detection of HLA (human leukocyte antigen) antibodies was performed using methods such as the LABScreen PRA Class I and Class II, LABScreen Single Antigen Class I and Class II, Luminex Platform. Reactive individuals to the screening tests (LABScreen PRA) were further investigated to determine the specificity of the antibodies detected (LABScreen Single Antigen) with a cutoff value of median fluorescence intensity ≥500. As a result, it was observed that two patients (33%) were positive in screening tests, one presenting with anti-HLA Class I and II sensitization and the other with anti-HLA class II. The specificity analysis showed that the patients sensitized to HLA class II presented 4 specificities, 3 of which immunologically relevant. In the second individual, 23 specificities were identified, 6 of which immunologically important for HLA class I and 4 specificities for HLA class II, 3 of these were immunologically important. All specificities detected had average fluorescence. These findings are suggestive that sinus-lifting procedures with allogeneic bone can induce immunological sensitization.

Sensitivity and specificity of automated analysis of single-field non-mydriatic fundus photographs by Bosch DR Algorithm—Comparison with mydriatic fundus photography (ETDRS) for screening in undiagnosed diabetic retinopathy

PubMed Central

Bawankar, Pritam; Shanbhag, Nita; K., S. Smitha; Dhawan, Bodhraj; Palsule, Aratee; Kumar, Devesh; Chandel, Shailja

2017-01-01

Diabetic retinopathy (DR) is a leading cause of blindness among working-age adults. Early diagnosis through effective screening programs is likely to improve vision outcomes. The ETDRS seven-standard-field 35-mm stereoscopic color retinal imaging (ETDRS) of the dilated eye is elaborate and requires mydriasis, and is unsuitable for screening. We evaluated an image analysis application for the automated diagnosis of DR from non-mydriatic single-field images. Patients suffering from diabetes for at least 5 years were included if they were 18 years or older. Patients already diagnosed with DR were excluded. Physiologic mydriasis was achieved by placing the subjects in a dark room. Images were captured using a Bosch Mobile Eye Care fundus camera. The images were analyzed by the Retinal Imaging Bosch DR Algorithm for the diagnosis of DR. All subjects also subsequently underwent pharmacological mydriasis and ETDRS imaging. Non-mydriatic and mydriatic images were read by ophthalmologists. The ETDRS readings were used as the gold standard for calculating the sensitivity and specificity for the software. 564 consecutive subjects (1128 eyes) were recruited from six centers in India. Each subject was evaluated at a single outpatient visit. Forty-four of 1128 images (3.9%) could not be read by the algorithm, and were categorized as inconclusive. In four subjects, neither eye provided an acceptable image: these four subjects were excluded from the analysis. This left 560 subjects for analysis (1084 eyes). The algorithm correctly diagnosed 531 of 560 cases. The sensitivity, specificity, and positive and negative predictive values were 91%, 97%, 94%, and 95% respectively. The Bosch DR Algorithm shows favorable sensitivity and specificity in diagnosing DR from non-mydriatic images, and can greatly simplify screening for DR. This also has major implications for telemedicine in the use of screening for retinopathy in patients with diabetes mellitus. PMID:29281690

Sensitivity and specificity of automated analysis of single-field non-mydriatic fundus photographs by Bosch DR Algorithm-Comparison with mydriatic fundus photography (ETDRS) for screening in undiagnosed diabetic retinopathy.

PubMed

Bawankar, Pritam; Shanbhag, Nita; K, S Smitha; Dhawan, Bodhraj; Palsule, Aratee; Kumar, Devesh; Chandel, Shailja; Sood, Suneet

2017-01-01

Diabetic retinopathy (DR) is a leading cause of blindness among working-age adults. Early diagnosis through effective screening programs is likely to improve vision outcomes. The ETDRS seven-standard-field 35-mm stereoscopic color retinal imaging (ETDRS) of the dilated eye is elaborate and requires mydriasis, and is unsuitable for screening. We evaluated an image analysis application for the automated diagnosis of DR from non-mydriatic single-field images. Patients suffering from diabetes for at least 5 years were included if they were 18 years or older. Patients already diagnosed with DR were excluded. Physiologic mydriasis was achieved by placing the subjects in a dark room. Images were captured using a Bosch Mobile Eye Care fundus camera. The images were analyzed by the Retinal Imaging Bosch DR Algorithm for the diagnosis of DR. All subjects also subsequently underwent pharmacological mydriasis and ETDRS imaging. Non-mydriatic and mydriatic images were read by ophthalmologists. The ETDRS readings were used as the gold standard for calculating the sensitivity and specificity for the software. 564 consecutive subjects (1128 eyes) were recruited from six centers in India. Each subject was evaluated at a single outpatient visit. Forty-four of 1128 images (3.9%) could not be read by the algorithm, and were categorized as inconclusive. In four subjects, neither eye provided an acceptable image: these four subjects were excluded from the analysis. This left 560 subjects for analysis (1084 eyes). The algorithm correctly diagnosed 531 of 560 cases. The sensitivity, specificity, and positive and negative predictive values were 91%, 97%, 94%, and 95% respectively. The Bosch DR Algorithm shows favorable sensitivity and specificity in diagnosing DR from non-mydriatic images, and can greatly simplify screening for DR. This also has major implications for telemedicine in the use of screening for retinopathy in patients with diabetes mellitus.

3D fluid-attenuated inversion recovery imaging: reduced CSF artifacts and enhanced sensitivity and specificity for subarachnoid hemorrhage.

PubMed

Lummel, N; Schoepf, V; Burke, M; Brueckmann, H; Linn, J

2011-12-01

FLAIR images are highly sensitive for SAH. However, CSF flow artifacts caused by conventional FLAIR can produce false-positive results. Here, we compare 3D and 3D FLAIR sequences, focusing on their potential for containing these artifacts and their sensitivity and specificity for detection of SAHs. We evaluated the following 4 FLAIR sequences: 1) 2D FLAIR at 1.5T, 2) 2D FLAIR, 3) 2D PROPELLER-FLAIR, and 4) 3D Cube-FLAIR at 3T. All sequences were performed in 5 healthy volunteers; sequences 2 and 4 were also performed under routine conditions in 10 patients with focal epilepsy and in 10 patients with SAH. Two neuroradiologists independently conducted the analysis. The presence of flow artifacts in the ventricles and cisterns of healthy volunteers and patients with epilepsy was evaluated and scored on a 4-point scale. Mean values were calculated and compared by using paired t tests. Sensitivity and specificity for SAH detection in sequences 2 and 4 were determined. Cube-FLAIR showed almost no CSF artifacts in the volunteers and the patients with epilepsy; therefore, it was superior to any other FLAIR (P < .001). Sensitivity and specificity of SAH detection by 3T FLAIR were 58.3% and 89.4%, respectively, whereas Cube-FLAIR had a sensitivity of 95% and a specificity of 100%. Cube-FLAIR allows FLAIR imaging with almost no CSF artifacts and is, thus, particularly useful for SAH detection.

Clinical validation of a highly sensitive assay to detect EGFR mutations in plasma cell-free DNA from patients with advanced lung adenocarcinoma.

PubMed

Li, Yuping; Xu, Hanyan; Su, Shanshan; Ye, Junru; Chen, Junjie; Jin, Xuru; Lin, Quan; Zhang, Dongqing; Ye, Caier; Chen, Chengshui

2017-01-01

Circulating tumor DNA (ctDNA) is a promising biomarker for noninvasive epidermal growth factor receptor (EGFR) mutations detection in lung cancer patients, but the existing methods have limitations in sensitivity or in availability. In this study, we evaluated the performance of a novel assay called ADx-SuperARMS in detecting EGFR mutations in plasma cell-free DNA from patients with advanced lung adenocarcinoma. A total of 109 patients with metastatic advanced adenocarcinoma were recruited who provided both blood samples and matched tumor tissue samples. EGFR mutation status in plasma samples were tested with ADx-SuperARMS EGFR assay and tumor tissue samples were tested with ADx-ARMS EGFR assay. The clinical sensitivity, specificity, positive prediction value (PPV), and negative prediction value (NPV) of ADx-SuperARMS EGFR assay were calculated by using EGFR mutation status in tumor tissue as standard reference. A receiver operating characteristic (ROC) analysis was implemented and an area under the curve (AUC) was calculated to evaluate sensitivity and specificity of exon 19 deletion (E19Del) and L858R mutation detection. The objective response rate (ORR) were calculated according to the EGFR mutation status determined by ADx-superARMS as well. 0.2% analytical sensitivity and 100% specificity of the ADx-SuperARMS EGFR assays for EGFR E19Del, L858R, and T790M mutants were confirmed by using a series of diluted cell line DNA. In the clinical study, EGFR mutations were detected in 45.9% (50/109) of the plasma samples and in 56.9% (62/109) of the matched tumor tissue samples. The sensitivity, specificity, PPV and NPV of the ADx-SuperARMS EGFR assay for plasma EGFR mutation detection were 82.0% (50/61), 100% (48/48), 100% (50/50), and 81.4% (48/59), respectively. In ROC analysis, ADx-SuperARMS achieved sensitivity and specificity of 88% and 99% in E19Dels as well as sensitivity and specificity of 89% and 100% in L858R, respectively. Among the 35 patients who were plasma EGFR mutation positive and treated with first generation of EGFR-tyrosine kinase inhibitors (TKIs), 23 (65.7%) achieved partial response, 11 (31.4%) sustained disease, and 1 (2.9%) progressive disease. The ORR and disease control rate (DCR) were 65.7% and 97.1%, respectively. ADx-SuperARMS EGFR assay is likely to be a highly sensitive and specific method to noninvasively detect plasma EGFR mutations of patients with advanced lung adenocarcinoma. The EGFR mutations detected by ADx-SuperARMS EGFR assay could predict the efficacy of the treatment with first generation of EGFR-TKIs. Hence, EGFR blood testing with ADx-SuperARMS could address the unmet clinical needs.

’Coxiella Burnetii’ Vaccine Development: Lipopolysaccharide Structural Analysis

DTIC Science & Technology

1991-02-20

Analytical instrumentation and methodology is presented for the determination of endotoxin -related structures at much improved sensitivity and... ENDOTOXIN CHARACTERIZATION BY SFC .......................... 10 III. COXIELLA BURNETII LPS CHARACTERIZATION A. EXPERIMENTAL...period for the determination of endotoxin -related structures at much improved sensitivity and specificity. Reports, and their applications, are listed in

Chemical derivatization for enhancing sensitivity during LC/ESI-MS/MS quantification of steroids in biological samples: a review.

PubMed

Higashi, Tatsuya; Ogawa, Shoujiro

2016-09-01

Sensitive and specific methods for the detection, characterization and quantification of endogenous steroids in body fluids or tissues are necessary for the diagnosis, pathological analysis and treatment of many diseases. Recently, liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) has been widely used for these purposes due to its specificity and versatility. However, the ESI efficiency and fragmentation behavior of some steroids are poor, which lead to a low sensitivity. Chemical derivatization is one of the most effective methods to improve the detection characteristics of steroids in ESI-MS/MS. Based on this background, this article reviews the recent advances in chemical derivatization for the trace quantification of steroids in biological samples by LC/ESI-MS/MS. The derivatization in ESI-MS/MS is based on tagging a proton-affinitive or permanently charged moiety on the target steroid. Introduction/formation of a fragmentable moiety suitable for the selected reaction monitoring by the derivatization also enhances the sensitivity. The stable isotope-coded derivatization procedures for the steroid analysis are also described. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effectiveness of Quantitative Real Time PCR in Long-Term Follow-up of Chronic Myeloid Leukemia Patients.

PubMed

Savasoglu, Kaan; Payzin, Kadriye Bahriye; Ozdemirkiran, Fusun; Berber, Belgin

2015-08-01

To determine the use of the Quantitative Real Time PCR (RQ-PCR) assay follow-up with Chronic Myeloid Leukemia (CML) patients. Cross-sectional observational. Izmir Ataturk Education and Research Hospital, Izmir, Turkey, from 2009 to 2013. Cytogenetic, FISH, RQ-PCR test results from 177 CMLpatients' materials selected between 2009 - 2013 years was set up for comparison analysis. Statistical analysis was performed to compare between FISH, karyotype and RQ-PCR results of the patients. Karyotyping and FISH specificity and sensitivity rates determined by ROC analysis compared with RQ-PCR results. Chi-square test was used to compare test failure rates. Sensitivity and specificity values were determined for karyotyping 17.6 - 98% (p=0.118, p > 0.05) and for FISH 22.5 - 96% (p=0.064, p > 0.05) respectively. FISH sensitivity was slightly higher than karyotyping but there was calculated a strong correlation between them (p < 0.001). RQ-PCR test failure rate did not correlate with other two tests (p > 0.05); however, karyotyping and FISH test failure rate was statistically significant (p < 0.001). Besides, the situation needed for karyotype analysis, RQ-PCR assay can be used alone in the follow-up of CMLdisease.

Optimal Hemoglobin A1c Levels for Screening of Diabetes and Prediabetes in the Japanese Population.

PubMed

Shimodaira, Masanori; Okaniwa, Shinji; Hanyu, Norinao; Nakayama, Tomohiro

2015-01-01

The aim of this study was to evaluate the utility of hemoglobin A1c (HbA1c) to identify individuals with diabetes and prediabetes in the Japanese population. A total of 1372 individuals without known diabetes were selected for this study. A 75 g oral glucose tolerance test (OGTT) was used to diagnose diabetes and prediabetes. The ability of HbA1c to detect diabetes and prediabetes was investigated using receiver operating characteristic (ROC) analysis. The kappa (κ) coefficient was used to test the agreement between HbA1c categorization and OGTT-based diagnosis. ROC analysis demonstrated that HbA1c was a good test to identify diabetes and prediabetes, with areas under the curve of 0.918 and 0.714, respectively. Optimal HbA1c cutoffs for diagnosing diabetes and prediabetes were 6.0% (sensitivity 83.7%, specificity 87.6%) and 5.7% (sensitivity 60.6%, specificity 72.1%), respectively, although the cutoff for prediabetes showed low accuracy (67.6%) and a high false-negative rate (39.4%). Agreement between HbA1c categorization and OGTT-based diagnosis was low in diabetes (κ = 0.399) and prediabetes (κ = 0.324). In Japanese subjects, the HbA1c cutoff of 6.0% had appropriate sensitivity and specificity for diabetes screening, whereas the cutoff of 5.7% had modest sensitivity and specificity in identifying prediabetes. Thus, HbA1c may be inadequate as a screening tool for prediabetes.

Digital breast tomosynthesis for breast cancer screening and diagnosis in women with dense breasts - a systematic review and meta-analysis.

PubMed

Phi, Xuan-Anh; Tagliafico, Alberto; Houssami, Nehmat; Greuter, Marcel J W; de Bock, Geertruida H

2018-04-03

This study aimed to systematically review and to meta-analyse the accuracy of digital breast tomosynthesis (DBT) versus digital mammography (DM) in women with mammographically dense breasts in screening and diagnosis. Two independent reviewers identified screening or diagnostic studies reporting at least one of four outcomes (cancer detection rate-CDR, recall rate, sensitivity and specificity) for DBT and DM in women with mammographically dense breasts. Study quality was assessed using QUADAS-2. Meta-analysis of CDR and recall rate used a random effects model. Summary ROC curve summarized sensitivity and specificity. Sixteen studies were included (five diagnostic; eleven screening). In diagnosis, DBT increased sensitivity (84%-90%) versus DM alone (69%-86%) but not specificity. DBT improved CDR versus DM alone (RR: 1.16, 95% CI 1.02-1.31). In screening, DBT + DM increased CDR versus DM alone (RR: 1.33, 95% CI 1.20-1.47 for retrospective studies; RR: 1.52, 95% CI 1.08-2.11 for prospective studies). Recall rate was significantly reduced by DBT + DM in retrospective studies (RR: 0.72, 95% CI 0.64-0.80) but not in two prospective studies (RR: 1.12, 95% CI 0.76-1.63). In women with mammographically dense breasts, DBT+/-DM increased CDR significantly (versus DM) in screening and diagnosis. In diagnosis, DBT+/-DM increased sensitivity but not specificity. The effect of DBT + DM on recall rate in screening dense breasts varied between studies.

Imaging modalities in the diagnosis of pancreatic adenocarcinoma: A systematic review and meta-analysis of sensitivity, specificity and diagnostic accuracy.

PubMed

Toft, James; Hadden, William J; Laurence, Jerome M; Lam, Vincent; Yuen, Lawrence; Janssen, Anna; Pleass, Henry

2017-07-01

Pancreatic cancer, primarily pancreatic ductal adenocarcinoma (PDAC), accounts for 2.4% of cancer diagnoses and 5.8% of cancer death annually. Early diagnoses can improve 5-year survival in PDAC. The aim of this systematic review was to determine the sensitivity, specificity and diagnostic accuracy values for MRI, CT, PET&PET/CT, EUS and transabdominal ultrasound (TAUS) in the diagnosis of PDAC. A systematic review was undertaken to identify studies reporting sensitivity, specificity and/or diagnostic accuracy for the diagnosis of PDAC with MRI, CT, PET, EUS or TAUS. Proportional meta-analysis was performed for each modality. A total of 5399 patients, 3567 with PDAC, from 52 studies were included. The sensitivity, specificity and diagnostic accuracy were 93% (95% CI=88-96), 89% (95% CI=82-94) and 90% (95% CI=86-94) for MRI; 90% (95% CI=87-93), 87% (95% CI=79-93) and 89% (95% CI=85-93) for CT; 89% (95% CI=85-93), 70% (95% CI=54-84) and 84% (95% CI=79-89) for PET; 91% (95% CI=87-94), 86% (95% CI=81-91) and 89% (95% CI=87-92) for EUS; and 88% (95% CI=86-90), 94% (95% CI=87-98) and 91% (95% C=87-93) for TAUS. This review concludes all modalities, except for PET, are equivalent within 95% confidence intervals for the diagnosis of PDAC. Copyright © 2017 Elsevier B.V. All rights reserved.

Accuracy of combined dynamic contrast-enhanced magnetic resonance imaging and diffusion-weighted imaging for breast cancer detection: a meta-analysis.

PubMed

Zhang, Li; Tang, Min; Min, Zhiqian; Lu, Jun; Lei, Xiaoyan; Zhang, Xiaoling

2016-06-01

Magnetic resonance imaging (MRI) is increasingly being used to examine patients with suspected breast cancer. To determine the diagnostic performance of combined dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and diffusion-weighted imaging (DWI) for breast cancer detection. A comprehensive search of the PUBMED, EMBASE, Web of Science, and Cochrane Library databases was performed up to September 2014. Statistical analysis included pooling of sensitivity and specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and diagnostic accuracy using the summary receiver operating characteristic (SROC). All analyses were conducted using STATA (version 12.0), RevMan (version 5.2), and Meta-Disc 1.4 software programs. Fourteen studies were analyzed, which included a total of 1140 patients with 1276 breast lesions. The pooled sensitivity and specificity of combined DCE-MRI and DWI were 91.6% and 85.5%, respectively. The pooled sensitivity and specificity of DWI-MRI were 86.0% and 75.6%, respectively. The pooled sensitivity and specificity of DCE-MRI were 93.2% and 71.1%. The area under the SROC curve (AUC-SROC) of combined DCE-MRI and DWI was 0.94, the DCE-MRI of 0.85. Deeks testing confirmed no significant publication bias in all studies. Combined DCE-MRI and DWI had superior diagnostic accuracy than either DCE-MRI or DWI alone for the diagnosis of breast cancer. © The Foundation Acta Radiologica 2015.

Comparison of digital tomosynthesis and chest radiography for the detection of pulmonary nodules: systematic review and meta-analysis

PubMed Central

Kim, Jun H; Lee, Kyung H; Kim, Kyoung-Tae; Ahn, Hyeong S; Kim, Yeo J; Lee, Ha Y; Jeon, Yong S

2016-01-01

Objective: To compare the diagnostic accuracy of digital tomosynthesis (DTS) with that of chest radiography for the detection of pulmonary nodules by meta-analysis. Methods: A systematic literature search was performed to identify relevant original studies from 1 January 1 1976 to 31 August 31 2016. The quality of included studies was assessed by quality assessment of diagnostic accuracy studies-2. Per-patient data were used to calculate the sensitivity and specificity and per-lesion data were used to calculate the detection rate. Summary receiver-operating characteristic curves were drawn for pulmonary nodule detection. Results: 16 studies met the inclusion criteria. 1017 patients on a per-patient basis and 2159 lesions on a per-lesion basis from 16 eligible studies were evaluated. The pooled patient-based sensitivity of DTS was 0.85 [95% confidence interval (CI) 0.83–0.88] and the specificity was 0.95 (0.93–0.96). The pooled sensitivity and specificity of chest radiography were 0.47 (0.44–0.51) and 0.37 (0.34–0.40), respectively. The per-lesion detection rate was 2.90 (95% CI 2.63–3.19). Conclusion: DTS has higher diagnostic accuracy than chest radiography for detection of pulmonary nodules. Chest radiography has low sensitivity but similar specificity, comparable with that of DTS. Advances in knowledge: DTS has higher diagnostic accuracy than chest radiography for the detection of pulmonary nodules. PMID:27759428

Commercial test kits for detection of Lyme borreliosis: a meta-analysis of test accuracy

PubMed Central

Cook, Michael J; Puri, Basant K

2016-01-01

The clinical diagnosis of Lyme borreliosis can be supported by various test methodologies; test kits are available from many manufacturers. Literature searches were carried out to identify studies that reported characteristics of the test kits. Of 50 searched studies, 18 were included where the tests were commercially available and samples were proven to be positive using serology testing, evidence of an erythema migrans rash, and/or culture. Additional requirements were a test specificity of ≥85% and publication in the last 20 years. The weighted mean sensitivity for all tests and for all samples was 59.5%. Individual study means varied from 30.6% to 86.2%. Sensitivity for each test technology varied from 62.4% for Western blot kits, and 62.3% for enzyme-linked immunosorbent assay tests, to 53.9% for synthetic C6 peptide ELISA tests and 53.7% when the two-tier methodology was used. Test sensitivity increased as dissemination of the pathogen affected different organs; however, the absence of data on the time from infection to serological testing and the lack of standard definitions for “early” and “late” disease prevented analysis of test sensitivity versus time of infection. The lack of standardization of the definitions of disease stage and the possibility of retrospective selection bias prevented clear evaluation of test sensitivity by “stage”. The sensitivity for samples classified as acute disease was 35.4%, with a corresponding sensitivity of 64.5% for samples from patients defined as convalescent. Regression analysis demonstrated an improvement of 4% in test sensitivity over the 20-year study period. The studies did not provide data to indicate the sensitivity of tests used in a clinical setting since the effect of recent use of antibiotics or steroids or other factors affecting antibody response was not factored in. The tests were developed for only specific Borrelia species; sensitivities for other species could not be calculated. PMID:27920571

Comparative Study of rK39 Leishmania Antigen for Serodiagnosis of Visceral Leishmaniasis: Systematic Review with Meta-Analysis

PubMed Central

Maia, Zuinara; Lírio, Monique; Mistro, Sóstenes; Mendes, Carlos Maurício Cardeal; Mehta, Sanjay R.; Badaro, Roberto

2012-01-01

Background The rK39 recombinant protein is derived from a specific antigen produced by the Leishmania donovani complex, and has been used in the last two decades for the serodiagnosis of visceral leishmaniasis. We present here a systematic review and meta-analysis of studies evaluating serologic assays to diagnose visceral leishmaniasis to determine the accuracy of rK39 antigen in comparison to the use of other antigen preparations. Methodology/Principal Findings A systematic review with meta-analysis of the literature was performed to compare the rK39 strip-test and ELISA formats against serological tests using promastigote antigens derived from whole or soluble parasites for Direct Aglutination Test (DAT), Indirect Immunofluorescence test (IFAT) and ELISA with a promastigote antigen preparation (p-ELISA). Gold standard diagnosis was defined by the demonstration of amastigotes on hematological specimens. A database search was performed on Medline, Lilacs, Scopus, Isi Web of Science, and Cochrane Library. Quality of data was assessed using the QUADAS questionnaire. A search of the electronic databases found 352 papers of which only 14 fulfilled the selection criteria. Three evaluated the rK39 ELISA, while 13 evaluated the rK39 immunochromatographic strip test. The summarized sensitivity for the rK39-ELISA was 92% followed by IFAT 88% and p-ELISA 87%. The summarized specificity for the three diagnostic tests was 81%, 90%, and 77%. Studies comparing the rK39 strip test with DAT found a similar sensitivity of 94%, although the DAT had a slightly higher specificity. The rK39 strip test was more sensitive and specific than the IFAT and p-ELISA. We did not detect any difference in the sensitivity and specificity between strips produced by different manufacturers. Conclusions The rK39 protein used either in a strip test or in an ELISA, and the DAT are the best choices for implementation of rapid, easy and efficient test for serodiagnosis of VL. PMID:22303488

Comparative study of rK39 Leishmania antigen for serodiagnosis of visceral leishmaniasis: systematic review with meta-analysis.

PubMed

Maia, Zuinara; Lírio, Monique; Mistro, Sóstenes; Mendes, Carlos Maurício Cardeal; Mehta, Sanjay R; Badaro, Roberto

2012-01-01

The rK39 recombinant protein is derived from a specific antigen produced by the Leishmania donovani complex, and has been used in the last two decades for the serodiagnosis of visceral leishmaniasis. We present here a systematic review and meta-analysis of studies evaluating serologic assays to diagnose visceral leishmaniasis to determine the accuracy of rK39 antigen in comparison to the use of other antigen preparations. A systematic review with meta-analysis of the literature was performed to compare the rK39 strip-test and ELISA formats against serological tests using promastigote antigens derived from whole or soluble parasites for Direct Aglutination Test (DAT), Indirect Immunofluorescence test (IFAT) and ELISA with a promastigote antigen preparation (p-ELISA). Gold standard diagnosis was defined by the demonstration of amastigotes on hematological specimens. A database search was performed on Medline, Lilacs, Scopus, Isi Web of Science, and Cochrane Library. Quality of data was assessed using the QUADAS questionnaire. A search of the electronic databases found 352 papers of which only 14 fulfilled the selection criteria. Three evaluated the rK39 ELISA, while 13 evaluated the rK39 immunochromatographic strip test. The summarized sensitivity for the rK39-ELISA was 92% followed by IFAT 88% and p-ELISA 87%. The summarized specificity for the three diagnostic tests was 81%, 90%, and 77%. Studies comparing the rK39 strip test with DAT found a similar sensitivity of 94%, although the DAT had a slightly higher specificity. The rK39 strip test was more sensitive and specific than the IFAT and p-ELISA. We did not detect any difference in the sensitivity and specificity between strips produced by different manufacturers. The rK39 protein used either in a strip test or in an ELISA, and the DAT are the best choices for implementation of rapid, easy and efficient test for serodiagnosis of VL.

Accuracy of MRI for the diagnosis of metastatic cervical lymphadenopathy in patients with thyroid cancer.

PubMed

Chen, Qinghua; Raghavan, Prashant; Mukherjee, Sugoto; Jameson, Mark J; Patrie, James; Xin, Wenjun; Xian, Junfang; Wang, Zhenchang; Levine, Paul A; Wintermark, Max

2015-10-01

The aim of this study was to systematically compare a comprehensive array of magnetic resonance (MR) imaging features in terms of their sensitivity and specificity to diagnose cervical lymph node metastases in patients with thyroid cancer. The study included 41 patients with thyroid malignancy who underwent surgical excision of cervical lymph nodes and had preoperative MR imaging ≤4weeks prior to surgery. Three head and neck neuroradiologists independently evaluated all the MR images. Using the pathology results as reference, the sensitivity, specificity and interobserver agreement of each MR imaging characteristic were calculated. On multivariate analysis, no single imaging feature was significantly correlated with metastasis. In general, imaging features demonstrated high specificity, but poor sensitivity and moderate interobserver agreement at best. Commonly used MR imaging features have limited sensitivity at correctly identifying cervical lymph node metastases in patients with thyroid cancer. A negative neck MR scan should not dissuade a surgeon from performing a neck dissection in patients with thyroid carcinomas.

GRIDSS: sensitive and specific genomic rearrangement detection using positional de Bruijn graph assembly

PubMed Central

Do, Hongdo; Molania, Ramyar

2017-01-01

The identification of genomic rearrangements with high sensitivity and specificity using massively parallel sequencing remains a major challenge, particularly in precision medicine and cancer research. Here, we describe a new method for detecting rearrangements, GRIDSS (Genome Rearrangement IDentification Software Suite). GRIDSS is a multithreaded structural variant (SV) caller that performs efficient genome-wide break-end assembly prior to variant calling using a novel positional de Bruijn graph-based assembler. By combining assembly, split read, and read pair evidence using a probabilistic scoring, GRIDSS achieves high sensitivity and specificity on simulated, cell line, and patient tumor data, recently winning SV subchallenge #5 of the ICGC-TCGA DREAM8.5 Somatic Mutation Calling Challenge. On human cell line data, GRIDSS halves the false discovery rate compared to other recent methods while matching or exceeding their sensitivity. GRIDSS identifies nontemplate sequence insertions, microhomologies, and large imperfect homologies, estimates a quality score for each breakpoint, stratifies calls into high or low confidence, and supports multisample analysis. PMID:29097403

Value and impact factors of multidetector computed tomography in diagnosis of preoperative lymph node metastasis in gastric cancer: A PRISMA-compliant systematic review and meta-analysis.

PubMed

Luo, Mingxu; Lv, You; Guo, Xiuyu; Song, Hongmei; Su, Guoqiang; Chen, Bo

2017-08-01

Multidetector computed tomography (MDCT) exhibited wide ranges of sensitivities and specificities for lymph node assessment of gastric cancer (GC) in several individual studies. This present meta-analysis was carried out to evaluate the value of MDCT in diagnosis of preoperative lymph node metastasis (LNM) and to explore the impact factors that might explain the heterogeneity of its diagnostic accuracy in GC. A comprehensive search was conducted to collect all the relevant studies about the value of MDCT in assessing LNM of GC within the PubMed, Cochrane library and Embase databases up to Feb 2, 2016. Two investigators independently screened the studies, extracted data, and evaluated the quality of included studies. The sensitivity, specificity, and area under ROC curve (AUC) were pooled to estimate the overall accuracy of MDCT. Meta-regression and subgroup analysis were carried out to identify the possible factors influencing the heterogeneity of the accuracy. A total of 27 studies with 6519 subjects were finally included. Overall, the pooled sensitivity, specificity, and AUC were 0.67 (95% CI: 0.56-0.77), 0.86 (95% CI: 0.81-0.90), and 0.86 (95% CI: 0.83-0.89), respectively. Meta-regression revealed that MDCT section thickness, proportion of serosal invasion, and publication year were the main significant impact factors in sensitivity, and MDCT section thickness, multiplanar reformation (MPR), and reference standard were the main significant impact factors in specificity. After the included studies were divided into 2 groups (Group A: studies with proportion of serosa-invasive GC subjects ≥50%; Group B: studies with proportion of serosa-invasive GC subjects <50%), the pooled sensitivity in Group A was significantly higher than in Group B (0.84 [95% CI: 0.75-0.90] vs 0.55 [95% CI: 0.41-0.68], P < .01). For early gastric cancer (EGC), the pooled sensitivity, specificity, and AUC were 0.34 (95% CI: 0.15-0.61), 0.91 (95% CI: 0.84-0.95), and 0.83 (95% CI: 0.80-0.86), respectively. To summarize, MDCT tends to be adequate to assess preoperative LNM in serosa-invasive GC, but insufficient for non-serosa-invasive GC (particularly for EGC) owing to its low sensitivity. Proportion of serosa-invasive GC subjects, MDCT section thickness, MPR, and reference standard are the main factors influencing its diagnostic accuracy.

Bayesian Estimation of Fish Disease Prevalence from Pooled Samples Incorporating Sensitivity and Specificity

NASA Astrophysics Data System (ADS)

Williams, Christopher J.; Moffitt, Christine M.

2003-03-01

An important emerging issue in fisheries biology is the health of free-ranging populations of fish, particularly with respect to the prevalence of certain pathogens. For many years, pathologists focused on captive populations and interest was in the presence or absence of certain pathogens, so it was economically attractive to test pooled samples of fish. Recently, investigators have begun to study individual fish prevalence from pooled samples. Estimation of disease prevalence from pooled samples is straightforward when assay sensitivity and specificity are perfect, but this assumption is unrealistic. Here we illustrate the use of a Bayesian approach for estimating disease prevalence from pooled samples when sensitivity and specificity are not perfect. We also focus on diagnostic plots to monitor the convergence of the Gibbs-sampling-based Bayesian analysis. The methods are illustrated with a sample data set.

Enhanced sensitivity in detection of antiviral antibody responses using biotinylation of foot-and-mouth disease virus (FMDV) capsids.

PubMed

Kenney, Mary; Waters, Ryan A; Rieder, Elizabeth; Pega, Juan; Perez-Filguera, Mariano; Golde, William T

2017-11-01

Analysis of the immune response to infection of livestock by foot-and-mouth disease virus (FMDV) is most often reported as the serum antibody response to the virus. While measurement of neutralizing antibody has been sensitive and specific, measurements of the quality of the antibody response are less robust. Determining the immunoglobulin (Ig) isotype of the serum antibody response provides a deeper understanding of the biology of the response and more sensitive methods for these assays will facilitate analyses of B cell mediated immunity. We tested the hypothesis that using the virus as the molecular probe could be achieved by adding tags to the surface of the FMDV capsid, and that would enhance sensitivity in assays for anti-FMDV antibody responses. The use of a FLAG-tagged virus in these assays failed to yield improvement whereas chemically biotinylating the virus capsid resulted in significant enhancement of the signal. Here we describe methods using biotinylated virus for measuring anti-viral antibody in serum and antibody secreting cells (ASCs) in blood that are sensitive and specific. Finally, we describe using the biotinylated virus in flow cytometry where such assays should greatly enhance the analysis of anti-virus antibody producing B cells, allowing the investigator to focus on only the FMDV specific B cells when analyzing the development of the B cell response to either infection or vaccination. Published by Elsevier B.V.

Quantitative assessment of serum-specific IgE in the diagnosis of human cystic echinococcosis.

PubMed

Marinova, I; Nikolov, G; Michova, A; Kurdova, R; Petrunov, B

2011-07-01

Anti-Echinococcus serum immunoglobulin (Ig)E was assessed by the ImmunoCAP system and compared with anti-Echinococcus serum IgG assessed by enzyme-linked immunosorbent assay (ELISA) and Western blot. The ImmunoCAP system revealed very high specificity (one false positive of 110 healthy individuals), low cross-reactivity (one false positive of 58 patients with other diseases) and decreased sensitivity (73.55%). Receiver operating characteristic analysis displayed a beneficial diagnostic value with high accuracy. Comparison of the ImmunoCAP system with ELISA and Western blot showed significantly higher specificity and significantly lower cross-reactivity compared with the ELISA. Examination of sera from 155 patients with cystic echinococcosis (CE) showed varying levels of anti-Echinococcus IgE (range, 0.01-118.33 kUA/L). However, most samples had moderately elevated IgE levels. Analysis of serum-specific IgE revealed significantly higher sensitivity of the ImmunoCAP system and significantly higher antibody levels in hepatic CE compared with pulmonary CE. © 2011 Blackwell Publishing Ltd.

Gender-specific heart rate dynamics in severe intrauterine growth-restricted fetuses.

PubMed

Gonçalves, Hernâni; Bernardes, João; Ayres-de-Campos, Diogo

2013-06-01

Management of intrauterine growth restriction (IUGR) remains a major issue in perinatology. The objective of this paper was the assessment of gender-specific fetal heart rate (FHR) dynamics as a diagnostic tool in severe IUGR. FHR was analyzed in the antepartum period in 15 severe IUGR fetuses and 18 controls, matched for gestational age, in relation to fetal gender. Linear and entropy methods, such as mean FHR (mFHR), low (LF), high (HF) and movement frequency (MF), approximate, sample and multiscale entropy. Sensitivities and specificities were estimated using Fisher linear discriminant analysis and the leave-one-out method. Overall, IUGR fetuses presented significantly lower mFHR and entropy compared with controls. However, gender-specific analysis showed that significantly lower mFHR was only evident in IUGR males and lower entropy in IUGR females. In addition, lower LF/(MF+HF) was patent in IUGR females compared with controls, but not in males. Rather high sensitivities and specificities were achieved in the detection of the FHR recordings related with IUGR male fetuses, when gender-specific analysis was performed at gestational ages less than 34 weeks. Severe IUGR fetuses present gender-specific linear and entropy FHR changes, compared with controls, characterized by a significantly lower entropy and sympathetic-vagal balance in females than in males. These findings need to be considered in order to achieve better diagnostic results. Copyright © 2013 Elsevier Ltd. All rights reserved.

Evaluation of Swine-Specific PCR Assays Used for Fecal Source Tracking and Analysis of Molecular Diversity of Swine-Specific "Bacteroidales" Populations

EPA Science Inventory

In this study we evaluated specificity, distribution, and sensitivity of Bacteroidales – (PF163 and PigBac1) and methanogen-based (P23-2) assays proposed to detect swine fecal pollution in environmental waters. The assays were tested against 220 fecal DNA extracts derived from t...

Evaluation and optimisation of indel detection workflows for ion torrent sequencing of the BRCA1 and BRCA2 genes.

PubMed

Yeo, Zhen Xuan; Wong, Joshua Chee Leong; Rozen, Steven G; Lee, Ann Siew Gek

2014-06-24

The Ion Torrent PGM is a popular benchtop sequencer that shows promise in replacing conventional Sanger sequencing as the gold standard for mutation detection. Despite the PGM's reported high accuracy in calling single nucleotide variations, it tends to generate many false positive calls in detecting insertions and deletions (indels), which may hinder its utility for clinical genetic testing. Recently, the proprietary analytical workflow for the Ion Torrent sequencer, Torrent Suite (TS), underwent a series of upgrades. We evaluated three major upgrades of TS by calling indels in the BRCA1 and BRCA2 genes. Our analysis revealed that false negative indels could be generated by TS under both default calling parameters and parameters adjusted for maximum sensitivity. However, indel calling with the same data using the open source variant callers, GATK and SAMtools showed that false negatives could be minimised with the use of appropriate bioinformatics analysis. Furthermore, we identified two variant calling measures, Quality-by-Depth (QD) and VARiation of the Width of gaps and inserts (VARW), which substantially reduced false positive indels, including non-homopolymer associated errors without compromising sensitivity. In our best case scenario that involved the TMAP aligner and SAMtools, we achieved 100% sensitivity, 99.99% specificity and 29% False Discovery Rate (FDR) in indel calling from all 23 samples, which is a good performance for mutation screening using PGM. New versions of TS, BWA and GATK have shown improvements in indel calling sensitivity and specificity over their older counterpart. However, the variant caller of TS exhibits a lower sensitivity than GATK and SAMtools. Our findings demonstrate that although indel calling from PGM sequences may appear to be noisy at first glance, proper computational indel calling analysis is able to maximize both the sensitivity and specificity at the single base level, paving the way for the usage of this technology for future clinical genetic testing.

Evaluation of Four Diagnostic Tests for Insulin Dysregulation in Adult Light-Breed Horses.

PubMed

Dunbar, L K; Mielnicki, K A; Dembek, K A; Toribio, R E; Burns, T A

2016-05-01

Several tests have been evaluated in horses for quantifying insulin dysregulation to support a diagnosis of equine metabolic syndrome. Comparing the performance of these tests in the same horses will provide clarification of their accuracy in the diagnosis of equine insulin dysregulation. The aim of this study was to evaluate the agreement between basal serum insulin concentrations (BIC), the oral sugar test (OST), the combined glucose-insulin test (CGIT), and the frequently sampled insulin-modified intravenous glucose tolerance test (FSIGTT). Twelve healthy, light-breed horses. Randomized, prospective study. Each of the above tests was performed on 12 horses. Minimal model analysis of the FSIGTT was considered the reference standard and classified 7 horses as insulin resistant (IR) and 5 as insulin sensitive (IS). In contrast, BIC and OST assessment using conventional cut-off values classified all horses as IS. Kappa coefficients, measuring agreement among BIC, OST, CGIT, and FSIGTT were poor to fair. Sensitivity of the CGIT (positive phase duration of the glucose curve >45 minutes) was 85.7% and specificity was 40%, whereas CGIT ([insulin]45 >100 μIU/mL) sensitivity and specificity were 28.5% and 100%, respectively. Area under the glucose curve (AUCg0-120 ) was significantly correlated among the OST, CGIT, and FSIGTT, but Bland-Altman method and Lin's concordance coefficient showed a lack of agreement. Current criteria for diagnosis of insulin resistance using BIC and the OST are highly specific but lack sensitivity. The CGIT displayed better sensitivity and specificity, but modifications may be necessary to improve agreement with minimal model analysis. Copyright © 2016 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.

Molecular tools for diagnosis of visceral leishmaniasis: systematic review and meta-analysis of diagnostic test accuracy.

PubMed

de Ruiter, C M; van der Veer, C; Leeflang, M M G; Deborggraeve, S; Lucas, C; Adams, E R

2014-09-01

Molecular methods have been proposed as highly sensitive tools for the detection of Leishmania parasites in visceral leishmaniasis (VL) patients. Here, we evaluate the diagnostic accuracy of these tools in a meta-analysis of the published literature. The selection criteria were original studies that evaluate the sensitivities and specificities of molecular tests for diagnosis of VL, adequate classification of study participants, and the absolute numbers of true positives and negatives derivable from the data presented. Forty studies met the selection criteria, including PCR, real-time PCR, nucleic acid sequence-based amplification (NASBA), and loop-mediated isothermal amplification (LAMP). The sensitivities of the individual studies ranged from 29 to 100%, and the specificities ranged from 25 to 100%. The pooled sensitivity of PCR in whole blood was 93.1% (95% confidence interval [CI], 90.0 to 95.2), and the specificity was 95.6% (95% CI, 87.0 to 98.6). The specificity was significantly lower in consecutive studies, at 63.3% (95% CI, 53.9 to 71.8), due either to true-positive patients not being identified by parasitological methods or to the number of asymptomatic carriers in areas of endemicity. PCR for patients with HIV-VL coinfection showed high diagnostic accuracy in buffy coat and bone marrow, ranging from 93.1 to 96.9%. Molecular tools are highly sensitive assays for Leishmania detection and may contribute as an additional test in the algorithm, together with a clear clinical case definition. We observed wide variety in reference standards and study designs and now recommend consecutively designed studies. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Prospective identification of adolescent suicide ideation using classification tree analysis: Models for community-based screening.

PubMed

Hill, Ryan M; Oosterhoff, Benjamin; Kaplow, Julie B

2017-07-01

Although a large number of risk markers for suicide ideation have been identified, little guidance has been provided to prospectively identify adolescents at risk for suicide ideation within community settings. The current study addressed this gap in the literature by utilizing classification tree analysis (CTA) to provide a decision-making model for screening adolescents at risk for suicide ideation. Participants were N = 4,799 youth (Mage = 16.15 years, SD = 1.63) who completed both Waves 1 and 2 of the National Longitudinal Study of Adolescent to Adult Health. CTA was used to generate a series of decision rules for identifying adolescents at risk for reporting suicide ideation at Wave 2. Findings revealed 3 distinct solutions with varying sensitivity and specificity for identifying adolescents who reported suicide ideation. Sensitivity of the classification trees ranged from 44.6% to 77.6%. The tree with greatest specificity and lowest sensitivity was based on a history of suicide ideation. The tree with moderate sensitivity and high specificity was based on depressive symptoms, suicide attempts or suicide among family and friends, and social support. The most sensitive but least specific tree utilized these factors and gender, ethnicity, hours of sleep, school-related factors, and future orientation. These classification trees offer community organizations options for instituting large-scale screenings for suicide ideation risk depending on the available resources and modality of services to be provided. This study provides a theoretically and empirically driven model for prospectively identifying adolescents at risk for suicide ideation and has implications for preventive interventions among at-risk youth. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Diagnostic accuracy of magnetic resonance angiography for detection of coronary artery disease: a systematic review and meta-analysis.

PubMed

Di Leo, Giovanni; Fisci, Erica; Secchi, Francesco; Alì, Marco; Ambrogi, Federico; Sconfienza, Luca Maria; Sardanelli, Francesco

2016-10-01

To review the diagnostic performance of MR coronary angiography (MRCA) for coronary artery disease (CAD). Two independent reviewers searched on MEDLINE/EMBASE with the following inclusion criteria: 01/01/2000-03/23/2015 publication date; per-patient sensitivity/specificity for >50 % stenosis confirmed by conventional coronary angiography with raw data provided or retrievable; sample size >10. Quality was appraised using QUADAS2. Nine hundred eighteen studies were retrieved, 24 of them, including 1,638 patients, were selected. Using a bivariate model, the pooled sensitivity was 89 % (95 % confidence interval 86-92 %), the pooled specificity 72 % (63-79 %). Meta-regression did not show a significant impact on sensitivity/specificity for both year of publication and disease prevalence (p ≥ 0.114). Sensitivity of contrast-enhanced examinations (95 %, 90-97 %) was higher (p = 0.005) than that of unenhanced examinations (87 %, 83-90 %). Specificity of whole-heart acquisition mode (78 %, 72-84 %) was higher (p = 0.006) than that of targeted mode (57 %, 45-69 %). Specificity at 3 T (83 %, 69-92 %) was higher (p = 0.067) than that at 1.5 T (68 %, 60-76 %). Risk of bias and concerns regarding applicability were low. Sensitivity and specificity of MRCA for CAD were 89 % and 72 %, respectively. A specificity higher than 80 % may be obtained at 3 T. Whole-heart contrast-enhanced protocols should be preferred for a higher diagnostic performance. • MRCA sensitivity and specificity for CAD are below those of CTA. • Contrast administration increased sensitivity to 95 % (90-97 %), comparable with that of CTA. • Whole-heart mode increased specificity to 78 % (72-84 %), comparable with that of CTA. • Specificity at 3 T was borderline-significantly higher (p = 0.067) than at 1.5 T. • Whole-heart contrast-enhanced protocols are the best approach for MRCA.

Specific detection of Mycobacterium sp. genomic DNA using dual labeled gold nanoparticle based electrochemical biosensor.

PubMed

Thiruppathiraja, Chinnasamy; Kamatchiammal, Senthilkumar; Adaikkappan, Periyakaruppan; Santhosh, Devakirubakaran Jayakar; Alagar, Muthukaruppan

2011-10-01

The present study was aimed at the development and evaluation of a DNA electrochemical biosensor for Mycobacterium sp. genomic DNA detection in a clinical specimen using a signal amplifier as dual-labeled AuNPs. The DNA electrochemical biosensors were fabricated using a sandwich detection strategy involving two kinds of DNA probes specific to Mycobacterium sp. genomic DNA. The probes of enzyme ALP and the detector probe both conjugated on the AuNPs and subsequently hybridized with target DNA immobilized in a SAM/ITO electrode followed by characterization with CV, EIS, and DPV analysis using the electroactive species para-nitrophenol generated by ALP through hydrolysis of para-nitrophenol phosphate. The effect of enhanced sensitivity was obtained due to the AuNPs carrying numerous ALPs per hybridization and a detection limit of 1.25 ng/ml genomic DNA was determined under optimized conditions. The dual-labeled AuNP-facilitated electrochemical sensor was also evaluated by clinical sputum samples, showing a higher sensitivity and specificity and the outcome was in agreement with the PCR analysis. In conclusion, the developed electrochemical sensor demonstrated unique sensitivity and specificity for both genomic DNA and sputum samples and can be employed as a regular diagnostics tool for Mycobacterium sp. monitoring in clinical samples. Copyright © 2011 Elsevier Inc. All rights reserved.

Role of "Sural Sparing" Pattern (Absent/Abnormal Median and Ulnar with Present Sural SNAP) Compared to Absent/Abnormal Median or Ulnar with Normal Sural SNAP in Acute Inflammatory Demyelinating Polyneuropathy.

PubMed

Surpur, Spurthi Sunil; Govindarajan, Raghav

2017-01-01

Sural sparing defined as absent/abnormal median sensory nerve action potential (SNAP) amplitude or absent/abnormal ulnar SNAP amplitude with a normal sural SNAP amplitude is thought to be a marker for inflammatory demyelinating polyneuropathies. If sural sparing pattern specifically defined as absent/abnormal median and ulnar SNAP amplitude with normal sural SNAP amplitude (AMUNS) is sensitive and specific when compared with either absent/abnormal median and normal sural (AMNS) or absent/abnormal ulnar and normal sural (AUNS) for acute inflammatory demyelinating polyneuropathy (AIDP), chronic inflammatory demyelinating polyneuropathy (CIDP), select non-diabetic axonopathies (AXPs), and diabetic neuropathies (DNs). Retrospective analysis from 2001 to 2010 on all newly diagnosed AIDP, CIDP, select non-diabetic AXP, and DN. There were 20 AIDP and 23 CIDP. Twenty AXP and 50 DN patients between 2009 and 2010 were included as controls. AMUNS was seen in 65% of AIDP, 39% CIDP compared with 10% of AXP and 6% for DN with sensitivity of 51%, specificity of 92%, whereas the specificity of AMNS/AUNS was 73% and its sensitivity was 58%. If a patient has AMUNS they are >12 times more likely to have AIDP ( p  < 0.001). Sural sparing is highly specific but not sensitive when compared with either AMNS or AUNS in AIDP but does not add to sensitivity or specificity in CIDP.

Sensitivity and Specificity of Fenyö-Lindberg and Teicher Scores in the Diagnosis of Acute Appendicitis in Women

PubMed

Madžar, Zrinko; Kopljar, Mario; Madžar, Tomislav; Mesić, Marko; Mužina Mišić, Dubravka; Čiček, Slaven; Zovak, Mario

2016-12-01

The aim of the study was to assess diagnostic accuracy (sensitivity and specificity) of Fenyö-Lindberg and Teicher scores for distinguishing patients that need immediate surgical treatment from the others, in a female population from an urban setting. The study prospectively included 130 female patients admitted to the emergency department with abdominal pain indicating acute appendicitis. The scores and parameters of validity were calculated and compared to definitive diagnosis. For Fenyö-Lindberg score of -17 or less, 84.5% sensitivity, 55.6% specificity, 87.9% positive predictive value (PPV) and 48.4% negative predictive value (NPV) were recorded. For cut-off value greater or equal to -2, there was 59.2% sensitivity, 77.8% specificity, 91% PPV and 33.3% NPV. The Receiver Operating Characteristic (ROC) curve analysis of Fenyö-Lindberg score showed that the best single cut-off value for discriminating acute appendicitis in the study population was -15. For Teicher score, values greater than -3 yielded 89.3% sensitivity and 22.2% specificity, 81.4% PPV and 35.3% NPV. In conclusion, Fenyö-Lindberg score could be used as an additional tool to exclude appendicitis and avoid unnecessary appendectomies. Teicher score may help in recognizing patients with appendicitis. None of the two scores can indicate or decline appendectomy in all cases. Scoring systems may be useful for pointing to important clinical signs and symptoms in specific subpopulations.

Immuno-magnetic beads-based extraction-capillary zone electrophoresis-deep UV laser-induced fluorescence analysis of erythropoietin.

PubMed

Wang, Heye; Dou, Peng; Lü, Chenchen; Liu, Zhen

2012-07-13

Erythropoietin (EPO) is an important glycoprotein hormone. Recombinant human EPO (rhEPO) is an important therapeutic drug and can be also used as doping reagent in sports. The analysis of EPO glycoforms in pharmaceutical and sports areas greatly challenges analytical scientists from several aspects, among which sensitive detection and effective and facile sample preparation are two essential issues. Herein, we investigated new possibilities for these two aspects. Deep UV laser-induced fluorescence detection (deep UV-LIF) was established to detect the intrinsic fluorescence of EPO while an immuno-magnetic beads-based extraction (IMBE) was developed to specifically extract EPO glycoforms. Combined with capillary zone electrophoresis (CZE), CZE-deep UV-LIF allows high resolution glycoform profiling with improved sensitivity. The detection sensitivity was improved by one order of magnitude as compared with UV absorbance detection. An additional advantage is that the original glycoform distribution can be completely preserved because no fluorescent labeling is needed. By combining IMBE with CZE-deep UV-LIF, the overall detection sensitivity was 1.5 × 10⁻⁸ mol/L, which was enhanced by two orders of magnitude relative to conventional CZE with UV absorbance detection. It is applicable to the analysis of pharmaceutical preparations of EPO, but the sensitivity is insufficient for the anti-doping analysis of EPO in blood and urine. IMBE can be straightforward and effective approach for sample preparation. However, antibodies with high specificity were the key for application to urine samples because some urinary proteins can severely interfere the immuno-extraction. Copyright © 2012 Elsevier B.V. All rights reserved.

Computerized Lung Sound Analysis as diagnostic aid for the detection of abnormal lung sounds: a systematic review and meta-analysis

PubMed Central

Gurung, Arati; Scrafford, Carolyn G; Tielsch, James M; Levine, Orin S; Checkley, William

2011-01-01

Rationale The standardized use of a stethoscope for chest auscultation in clinical research is limited by its inherent inter-listener variability. Electronic auscultation and automated classification of recorded lung sounds may help prevent some these shortcomings. Objective We sought to perform a systematic review and meta-analysis of studies implementing computerized lung sounds analysis (CLSA) to aid in the detection of abnormal lung sounds for specific respiratory disorders. Methods We searched for articles on CLSA in MEDLINE, EMBASE, Cochrane Library and ISI Web of Knowledge through July 31, 2010. Following qualitative review, we conducted a meta-analysis to estimate the sensitivity and specificity of CLSA for the detection of abnormal lung sounds. Measurements and Main Results Of 208 articles identified, we selected eight studies for review. Most studies employed either electret microphones or piezoelectric sensors for auscultation, and Fourier Transform and Neural Network algorithms for analysis and automated classification of lung sounds. Overall sensitivity for the detection of wheezes or crackles using CLSA was 80% (95% CI 72–86%) and specificity was 85% (95% CI 78–91%). Conclusions While quality data on CLSA are relatively limited, analysis of existing information suggests that CLSA can provide a relatively high specificity for detecting abnormal lung sounds such as crackles and wheezes. Further research and product development could promote the value of CLSA in research studies or its diagnostic utility in clinical setting. PMID:21676606

Computerized lung sound analysis as diagnostic aid for the detection of abnormal lung sounds: a systematic review and meta-analysis.

PubMed

Gurung, Arati; Scrafford, Carolyn G; Tielsch, James M; Levine, Orin S; Checkley, William

2011-09-01

The standardized use of a stethoscope for chest auscultation in clinical research is limited by its inherent inter-listener variability. Electronic auscultation and automated classification of recorded lung sounds may help prevent some of these shortcomings. We sought to perform a systematic review and meta-analysis of studies implementing computerized lung sound analysis (CLSA) to aid in the detection of abnormal lung sounds for specific respiratory disorders. We searched for articles on CLSA in MEDLINE, EMBASE, Cochrane Library and ISI Web of Knowledge through July 31, 2010. Following qualitative review, we conducted a meta-analysis to estimate the sensitivity and specificity of CLSA for the detection of abnormal lung sounds. Of 208 articles identified, we selected eight studies for review. Most studies employed either electret microphones or piezoelectric sensors for auscultation, and Fourier Transform and Neural Network algorithms for analysis and automated classification of lung sounds. Overall sensitivity for the detection of wheezes or crackles using CLSA was 80% (95% CI 72-86%) and specificity was 85% (95% CI 78-91%). While quality data on CLSA are relatively limited, analysis of existing information suggests that CLSA can provide a relatively high specificity for detecting abnormal lung sounds such as crackles and wheezes. Further research and product development could promote the value of CLSA in research studies or its diagnostic utility in clinical settings. Copyright © 2011 Elsevier Ltd. All rights reserved.

Toward earlier detection of choroidal neovascularization secondary to age-related macular degeneration: multicenter evaluation of a preferential hyperacuity perimeter designed as a home device.

PubMed

Loewenstein, Anat; Ferencz, Joseph R; Lang, Yaron; Yeshurun, Itamar; Pollack, Ayala; Siegal, Ruth; Lifshitz, Tova; Karp, Joseph; Roth, Daniel; Bronner, Guri; Brown, Justin; Mansour, Sam; Friedman, Scott; Michels, Mark; Johnston, Richards; Rapp, Moshe; Havilio, Moshe; Rafaeli, Omer; Manor, Yair

2010-01-01

The primary purpose of this study was to evaluate the ability of a home device preferential hyperacuity perimeter to discriminate between patients with choroidal neovascularization (CNV) and intermediate age-related macular degeneration (AMD), and the secondary purpose was to investigate the dependence of sensitivity on lesion characteristics. All participants were tested with the home device in an unsupervised mode. The first part of this work was retrospective using tests performed by patients with intermediate AMD and newly diagnosed CNV. In the second part, the classifier was prospectively challenged with tests performed by patients with intermediate AMD and newly diagnosed CNV. The dependence of sensitivity on lesion characteristics was estimated with tests performed by patients with CNV of both parts. In 66 eyes with CNV and 65 eyes with intermediate AMD, both sensitivity and specificity were 0.85. In the retrospective part (34 CNV and 43 intermediate AMD), sensitivity and specificity were 0.85 +/- 0.12 (95% confidence interval) and 0.84 +/- 0.11 (95% confidence interval), respectively. In the prospective part (32 CNV and 22 intermediate AMD), sensitivity and specificity were 0.84 +/- 0.13 (95% confidence interval) and 0.86 +/- 0.14 (95% confidence interval), respectively. Chi-square analysis showed no dependence of sensitivity on type (P = 0.44), location (P = 0.243), or size (P = 0.73) of the CNV lesions. A home device preferential hyperacuity perimeter has good sensitivity and specificity in discriminating between patients with newly diagnosed CNV and intermediate AMD. Sensitivity is not dependent on lesion characteristics.

Accuracy of transvaginal ultrasound for diagnosis of deep endometriosis in uterosacral ligaments, rectovaginal septum, vagina and bladder: systematic review and meta-analysis.

PubMed

Guerriero, S; Ajossa, S; Minguez, J A; Jurado, M; Mais, V; Melis, G B; Alcazar, J L

2015-11-01

To review the diagnostic accuracy of transvaginal ultrasound (TVS) in the preoperative detection of endometriosis in the uterosacral ligaments (USL), rectovaginal septum (RVS), vagina and bladder in patients with clinical suspicion of deep infiltrating endometriosis (DIE). An extensive search was performed in MEDLINE (PubMed) and EMBASE for studies published between January 1989 and December 2014. Studies were considered eligible if they reported on the use of TVS for the preoperative detection of endometriosis in the USL, RVS, vagina and bladder in women with clinical suspicion of DIE using the surgical data as a reference standard. Study quality was assessed using the PRISMA guidelines and QUADAS-2 tool. Of the 801 citations identified, 11 studies (n = 1583) were considered eligible and were included in the meta-analysis. For detection of endometriosis in the USL, the overall pooled sensitivity and specificity of TVS were 53% (95%CI, 35-70%) and 93% (95%CI, 83-97%), respectively. The pretest probability of USL endometriosis was 54%, which increased to 90% when suspicion of endometriosis was present after TVS examination. For detection of endometriosis in the RVS, the overall pooled sensitivity and specificity were 49% (95%CI, 36-62%) and 98% (95%CI, 95-99%), respectively. The pretest probability of RVS endometriosis was 24%, which increased to 89% when suspicion of endometriosis was present after TVS examination. For detection of vaginal endometriosis, the overall pooled sensitivity and specificity were 58% (95%CI, 40-74%) and 96% (95%CI, 87-99%), respectively. The pretest probability of vaginal endometriosis was 17%, which increased to 76% when suspicion of endometriosis was present after TVS assessment. Substantial heterogeneity was found for sensitivity and specificity for all these locations. For detection of bladder endometriosis, the overall pooled sensitivity and specificity were 62% (95%CI, 40-80%) and 100% (95%CI, 97-100%), respectively. Moderate heterogeneity was found for sensitivity and specificity for bladder endometriosis. The pretest probability of bladder endometriosis was 5%, which increased to 92% when suspicion of endometriosis was present after TVS assessment. Overall diagnostic performance of TVS for detecting DIE in uterosacral ligaments, rectovaginal septum, vagina and bladder is fair with high specificity. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Detection of common carotid artery stenosis using duplex ultrasonography: a validation study with computed tomographic angiography.

PubMed

Slovut, David P; Romero, Javier M; Hannon, Kathleen M; Dick, James; Jaff, Michael R

2010-01-01

Severe stenosis of the common carotid artery (CCA), while uncommon, is associated with increased risk of transient ischemic attack and stroke. To date, no validated duplex ultrasound criteria have been established for grading the severity of CCA stenosis. The goal of this study was to use receiver-operating curve (ROC) analysis with computed tomographic angiography as the reference standard to establish duplex ultrasound criteria for diagnosing >or=50% CCA stenosis. The study cohort included 64 patients (42 men, 22 women) with a mean age of 65 +/- 12 years (range, 16-89 years) who had CCA peak systolic velocity (PSV) >or=150 cm/sec and underwent computed tomographic angiography (CTA) of the cervical and intracerebral vessels within 1 month of the duplex examination. One study was excluded because the CTA was technically inadequate, whereas another was excluded because the patient underwent bilateral CCA stenting. The CCA ipsilateral to any of the following was excluded from the analysis: innominate artery occlusion (n = 1), previous stenting of the ICA or CCA (n = 7), carotid endarterectomy (n = 1), or carotid-to-carotid bypass (n = 1). Thus, the data set included 62 patients and 115 vessels. Bland-Altman analysis was used to examine the agreement between two measures of luminal reduction measured by CTA: percent diameter stenosis and percent area stenosis. Receiver operating characteristic (ROC) analysis was used to determine optimal PSV and EDV thresholds for diagnosing >or=50% CCA stenosis. Severity of CCA stenosis was <50% in 76 vessels, 50%-59% in eight, 60%-69% in eight, 70%-79% in nine, 80%-89% in three, 90%-99% in five, and occluded in six. Duplex ultrasonography identified six of six (100%) patients with 100% CCA occlusion by CTA. Bland-Altman analysis showed poor agreement between percent stenosis determined by vessel diameter compared with percent stenosis determined by reduction in lumen area. Therefore, subsequent analysis was performed using percent stenosis by area. ROC analysis of different PSV thresholds for detecting stenosis >or=50% showed that >182 cm/sec was the most accurate with a sensitivity of 64% and specificity of 88% (P < .0001). Sensitivity, specificity, and accuracy of carotid duplex were higher when the stenosis was located in the mid or distal aspects of the CCA (sensitivity 76%, specificity 89%, area under curve 0.84, P < .001) than in the intrathoracic and proximal segment of the artery (P = NS). ROC analysis of different EDV thresholds for detecting CCA stenosis >or=50% showed that >30 cm/sec was the most accurate with a sensitivity of 54% and a specificity of 74% (P < .0239). Duplex ultrasonography is highly sensitive, specific, and accurate for detecting CCA lesions in the mid and distal CCA. Use of peak systolic velocity may lead to improved detection of CCA disease and initiation of appropriate therapy to reduce the risk of stroke. Copyright 2010 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Novel approach based on one-tube nested PCR and a lateral flow strip for highly sensitive diagnosis of tuberculous meningitis

PubMed Central

Sun, Yajuan; Chen, Jiajun; Li, Jia; Xu, Yawei; Jin, Hui; Xu, Na; Yin, Rui

2017-01-01

Rapid and sensitive detection of Mycobacterium tuberculosis (M. Tb) in cerebrospinal fluid is crucial in the diagnosis of tuberculous meningitis (TBM), but conventional diagnostic technologies have limited sensitivity and specificity or are time-consuming. In this work, a novel, highly sensitive molecular diagnostic method, one-tube nested PCR-lateral flow strip test (OTNPCR-LFST), was developed for detecting M. tuberculosis. This one-tube nested PCR maintains the sensitivity of conventional two-step nested PCR and reduces both the chance of cross-contamination and the time required for analysis. The PCR product was detected by a lateral flow strip assay, which provided a basis for migration of the test to a point-of-care (POC) microfluidic format. The developed assay had an improved sensitivity compared with traditional PCR, and the limit of detection was up to 1 fg DNA isolated from M. tuberculosis. The assay was also specific for M. tuberculosis, and no cross-reactions were found in other non-target bacteria. The application of this technique to clinical samples was successfully evaluated, and OTNPCR-LFST showed 89% overall sensitivity and 100% specificity for TBM patients. This one-tube nested PCR-lateral flow strip assay is useful for detecting M. tuberculosis in TBM due to its rapidity, high sensitivity and simple manipulation. PMID:29084241

Sensitivity and Specificity of the Coma Recovery Scale--Revised Total Score in Detection of Conscious Awareness.

PubMed

Bodien, Yelena G; Carlowicz, Cecilia A; Chatelle, Camille; Giacino, Joseph T

2016-03-01

To describe the sensitivity and specificity of Coma Recovery Scale-Revised (CRS-R) total scores in detecting conscious awareness. Data were retrospectively extracted from the medical records of patients enrolled in a specialized disorders of consciousness (DOC) program. Sensitivity and specificity analyses were completed using CRS-R-derived diagnoses of minimally conscious state (MCS) or emerged from minimally conscious state (EMCS) as the reference standard for conscious awareness and the total CRS-R score as the test criterion. A receiver operating characteristic curve was constructed to demonstrate the optimal CRS-R total cutoff score for maximizing sensitivity and specificity. Specialized DOC program. Patients enrolled in the DOC program (N=252, 157 men; mean age, 49y; mean time from injury, 48d; traumatic etiology, n=127; nontraumatic etiology, n=125; diagnosis of coma or vegetative state, n=70; diagnosis of MCS or EMCS, n=182). Not applicable. Sensitivity and specificity of CRS-R total scores in detecting conscious awareness. A CRS-R total score of 10 or higher yielded a sensitivity of .78 for correct identification of patients in MCS or EMCS, and a specificity of 1.00 for correct identification of patients who did not meet criteria for either of these diagnoses (ie, were diagnosed with vegetative state or coma). The area under the curve in the receiver operating characteristic curve analysis is .98. A total CRS-R score of 10 or higher provides strong evidence of conscious awareness but resulted in a false-negative diagnostic error in 22% of patients who demonstrated conscious awareness based on CRS-R diagnostic criteria. A cutoff score of 8 provides the best balance between sensitivity and specificity, accurately classifying 93% of cases. The optimal total score cutoff will vary depending on the user's objective. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Diagnostic accuracy of tests to detect Hepatitis C antibody: a meta-analysis and review of the literature.

PubMed

Tang, Weiming; Chen, Wen; Amini, Ali; Boeras, Debi; Falconer, Jane; Kelly, Helen; Peeling, Rosanna; Varsaneux, Olivia; Tucker, Joseph D; Easterbrook, Philippa

2017-11-01

Although direct-acting antivirals can achieve sustained virological response rates greater than 90% in Hepatitis C Virus (HCV) infected persons, at present the majority of HCV-infected individuals remain undiagnosed and therefore untreated. While there are a wide range of HCV serological tests available, there is a lack of formal assessment of their diagnostic performance. We undertook a systematic review and meta-analysis to evaluate he diagnostic accuracy of available rapid diagnostic tests (RDT) and laboratory based EIA assays in detecting antibodies to HCV. We used the PRISMA checklist and Cochrane guidance to develop our search protocol. The search strategy was registered in PROSPERO (CRD42015023567). The search focused on hepatitis C, diagnostic tests, and diagnostic accuracy within eight databases (MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, Science Citation Index Expanded, Conference Proceedings Citation Index-Science, SCOPUS, Literatura Latino-Americana e do Caribe em Ciências da Saúde and WHO Global Index Medicus. Studies were included if they evaluated an assay to determine the sensitivity and specificity of HCV antibody (HCV Ab) in humans. Two reviewers independently extracted data and performed a quality assessment of the studies using the QUADAS tool. We pooled test estimates using the DerSimonian-Laird method, by using the software R and RevMan. 5.3. A total of 52 studies were identified that included 52,673 unique test measurements. Based on five studies, the pooled sensitivity and specificity of HCV Ab rapid diagnostic tests (RDTs) were 98% (95% CI 98-100%) and 100% (95% CI 100-100%) compared to an enzyme immunoassay (EIA) reference standard. High HCV Ab RDTs sensitivity and specificity were observed across screening populations (general population, high risk populations, and hospital patients) using different reference standards (EIA, nucleic acid testing, immunoblot). There were insufficient studies to undertake subanalyses based on HIV co-infection. Oral HCV Ab RDTs also had excellent sensitivity and specificity compared to blood reference tests, respectively at 94% (95% CI 93-96%) and 100% (95% CI 100-100%). Among studies that assessed individual oral RDTs, the eight studies revealed that OraQuick ADVANCE® had a slightly higher sensitivity (98%, 95% CI 97-98%) compared to the other oral brands (pooled sensitivity: 88%, 95% CI 84-92%). RDTs, including oral tests, have excellent sensitivity and specificity compared to laboratory-based methods for HCV antibody detection across a wide range of settings. Oral HCV Ab RDTs had good sensitivity and specificity compared to blood reference standards.

A systematic review and meta-analysis of the diagnostic accuracy of point-of-care tests for the detection of hyperketonemia in dairy cows.

PubMed

Tatone, Elise H; Gordon, Jessica L; Hubbs, Jessie; LeBlanc, Stephen J; DeVries, Trevor J; Duffield, Todd F

2016-08-01

Several rapid tests for use on farm have been validated for the detection of hyperketonemia (HK) in dairy cattle, however the reported sensitivity and specificity of each method varies and no single study has compared them all. Meta-analysis of diagnostic test accuracy is becoming more common in human medical literature but there are few veterinary examples. The objective of this work was to perform a systematic review and meta-analysis to determine the point-of-care testing method with the highest combined sensitivity and specificity, the optimal threshold for each method, and to identify gaps in the literature. A comprehensive literature search resulted in 5196 references. After removing duplicates and performing relevance screening, 23 studies were included for the qualitative synthesis and 18 for the meta-analysis. The three index tests evaluated in the meta-analysis were: the Precision Xtra(®) handheld device measuring beta-hydroxybutyrate (BHB) concentration in whole blood, and Ketostix(®) and KetoTest(®) semi-quantitative strips measuring the concentration of acetoacetate in urine and BHB in milk, respectively. The diagnostic accuracy of the 3 index tests relative to the reference standard measurement of BHB in serum or whole blood between 1.0-1.4mmol/L was compared using the hierarchical summary receiver operator characteristic (HSROC) method. Subgroup analysis was conducted for each index test to examine the accuracy at different thresholds. The impact of the reference standard threshold, the reference standard method, the prevalence of HK in the population, the primary study source and risk of bias of the primary study was explored using meta-regression. The Precision Xtra(®) device had the highest summary sensitivity in whole blood BHB at 1.2mmol/L, 94.8% (CI95%: 92.6-97.0), and specificity, 97.5% (CI95%: 96.9-98.1). The threshold employed (1.2-1.4mmol/L) did not impact the diagnostic accuracy of the test. The Ketostix(®) and KetoTest(®) strips had the highest summary sensitivity and specificity when the trace and weak positive thresholds were used, respectively. Controlling for the source of publication, HK prevalence and reference standard employed did not impact the estimated sensitivity and specificity of the tests. Including only peer-reviewed studies reduced the number of primary studies evaluating the Precision Xtra(®) by 43% and Ketostix(®) by 33%. Diagnosing HK with blood, urine or milk are valid options, however, the diagnostic inaccuracy of urine and milk should be considered when making economic and treatment decisions. Copyright © 2016 Elsevier B.V. All rights reserved.

Deterministic Local Sensitivity Analysis of Augmented Systems - II: Applications to the QUENCH-04 Experiment Using the RELAP5/MOD3.2 Code System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ionescu-Bujor, Mihaela; Jin Xuezhou; Cacuci, Dan G.

2005-09-15

The adjoint sensitivity analysis procedure for augmented systems for application to the RELAP5/MOD3.2 code system is illustrated. Specifically, the adjoint sensitivity model corresponding to the heat structure models in RELAP5/MOD3.2 is derived and subsequently augmented to the two-fluid adjoint sensitivity model (ASM-REL/TF). The end product, called ASM-REL/TFH, comprises the complete adjoint sensitivity model for the coupled fluid dynamics/heat structure packages of the large-scale simulation code RELAP5/MOD3.2. The ASM-REL/TFH model is validated by computing sensitivities to the initial conditions for various time-dependent temperatures in the test bundle of the Quench-04 reactor safety experiment. This experiment simulates the reflooding with water ofmore » uncovered, degraded fuel rods, clad with material (Zircaloy-4) that has the same composition and size as that used in typical pressurized water reactors. The most important response for the Quench-04 experiment is the time evolution of the cladding temperature of heated fuel rods. The ASM-REL/TFH model is subsequently used to perform an illustrative sensitivity analysis of this and other time-dependent temperatures within the bundle. The results computed by using the augmented adjoint sensitivity system, ASM-REL/TFH, highlight the reliability, efficiency, and usefulness of the adjoint sensitivity analysis procedure for computing time-dependent sensitivities.« less

Critical comparison of diffuse reflectance spectroscopy and colorimetry as dermatological diagnostic tools for acanthosis nigricans: a chemometric approach.

PubMed

Devpura, Suneetha; Pattamadilok, Bensachee; Syed, Zain U; Vemulapalli, Pranita; Henderson, Marsha; Rehse, Steven J; Hamzavi, Iltefat; Lim, Henry W; Naik, Ratna

2011-06-01

Quantification of skin changes due to acanthosis nigricans (AN), a disorder common among insulin-resistant diabetic and obese individuals, was investigated using two optical techniques: diffuse reflectance spectroscopy (DRS) and colorimetry. Measurements were obtained from AN lesions on the neck and two control sites of eight AN patients. A principal component/discriminant function analysis successfully differentiated between AN lesion and normal skin with 87.7% sensitivity and 94.8% specificity in DRS measurements and 97.2% sensitivity and 96.4% specificity in colorimetry measurements.

Sensitivity of subject-specific models to Hill muscle-tendon model parameters in simulations of gait.

PubMed

Carbone, V; van der Krogt, M M; Koopman, H F J M; Verdonschot, N

2016-06-14

Subject-specific musculoskeletal (MS) models of the lower extremity are essential for applications such as predicting the effects of orthopedic surgery. We performed an extensive sensitivity analysis to assess the effects of potential errors in Hill muscle-tendon (MT) model parameters for each of the 56 MT parts contained in a state-of-the-art MS model. We used two metrics, namely a Local Sensitivity Index (LSI) and an Overall Sensitivity Index (OSI), to distinguish the effect of the perturbation on the predicted force produced by the perturbed MT parts and by all the remaining MT parts, respectively, during a simulated gait cycle. Results indicated that sensitivity of the model depended on the specific role of each MT part during gait, and not merely on its size and length. Tendon slack length was the most sensitive parameter, followed by maximal isometric muscle force and optimal muscle fiber length, while nominal pennation angle showed very low sensitivity. The highest sensitivity values were found for the MT parts that act as prime movers of gait (Soleus: average OSI=5.27%, Rectus Femoris: average OSI=4.47%, Gastrocnemius: average OSI=3.77%, Vastus Lateralis: average OSI=1.36%, Biceps Femoris Caput Longum: average OSI=1.06%) and hip stabilizers (Gluteus Medius: average OSI=3.10%, Obturator Internus: average OSI=1.96%, Gluteus Minimus: average OSI=1.40%, Piriformis: average OSI=0.98%), followed by the Peroneal muscles (average OSI=2.20%) and Tibialis Anterior (average OSI=1.78%) some of which were not included in previous sensitivity studies. Finally, the proposed priority list provides quantitative information to indicate which MT parts and which MT parameters should be estimated most accurately to create detailed and reliable subject-specific MS models. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sensitivity and specificity of dosing alerts for dosing errors among hospitalized pediatric patients

PubMed Central

Stultz, Jeremy S; Porter, Kyle; Nahata, Milap C

2014-01-01

Objectives To determine the sensitivity and specificity of a dosing alert system for dosing errors and to compare the sensitivity of a proprietary system with and without institutional customization at a pediatric hospital. Methods A retrospective analysis of medication orders, orders causing dosing alerts, reported adverse drug events, and dosing errors during July, 2011 was conducted. Dosing errors with and without alerts were identified and the sensitivity of the system with and without customization was compared. Results There were 47 181 inpatient pediatric orders during the studied period; 257 dosing errors were identified (0.54%). The sensitivity of the system for identifying dosing errors was 54.1% (95% CI 47.8% to 60.3%) if customization had not occurred and increased to 60.3% (CI 54.0% to 66.3%) with customization (p=0.02). The sensitivity of the system for underdoses was 49.6% without customization and 60.3% with customization (p=0.01). Specificity of the customized system for dosing errors was 96.2% (CI 96.0% to 96.3%) with a positive predictive value of 8.0% (CI 6.8% to 9.3). All dosing errors had an alert over-ridden by the prescriber and 40.6% of dosing errors with alerts were administered to the patient. The lack of indication-specific dose ranges was the most common reason why an alert did not occur for a dosing error. Discussion Advances in dosing alert systems should aim to improve the sensitivity and positive predictive value of the system for dosing errors. Conclusions The dosing alert system had a low sensitivity and positive predictive value for dosing errors, but might have prevented dosing errors from reaching patients. Customization increased the sensitivity of the system for dosing errors. PMID:24496386

Tumor necrosis factor α level in cerebrospinal fluid for bacterial and aseptic meningitis: a diagnostic meta-analysis.

PubMed

Lv, S; Zhao, J; Zhang, J; Kwon, S; Han, M; Bian, R; Fu, H; Zhang, Y; Pan, H

2014-08-01

In our previous study, tumor necrosis factor α (TNF-α) was identified as an effective target for sepsis patients (Int J Clin Pract, 68, 2014, 520). TNF-α in cerebrospinal fluid (CSF) was also investigated for its utility in the differential diagnosis of bacterial and aseptic meningitis. However, there has been neither definite nor convincing evidence so far. Here the overall diagnostic accuracy of TNF-α in differentiation between bacterial and aseptic meningitis was evaluated through the meta-analysis of diagnostic tests. The sensitivity, specificity and other measures of accuracy were pooled using random effect models. Summary receiver operating characteristic curves were used to assess overall test performance. Publication bias was evaluated using funnel plots, and sensitivity analysis was also introduced. A total of 21 studies involving bacterial meningitis (678) and aseptic meningitis (694) involved a total of 1372 patients. The pooled sensitivity and specificity for the TNF-α test were 0.83 [95% confidence interval (CI) 0.80-0.86, I(2)  = 65.1] and 0.92 (95% CI 0.89-0.94, I(2)  = 61.8), respectively. The positive likelihood ratio was 12.05 (95% CI 7.41-19.60, I(2)  = 36.5), the negative likelihood ratio was 0.17 (95% CI 0.13-0.24, I(2)  = 59.4), and TNF-α was significantly associated with bacterial meningitis, with a diagnostic odds ratio of 49.84 (95% CI 28.53-87.06, I(2)  = 47.9). The overall accuracy of the TNF-α test was very high with the area under the curve 0.9317. Publication bias was absent, and sensitivity analysis suggested that our results were highly stable. Our meta-analysis suggested that TNF-α could be recommended as a useful marker for diagnosis of bacterial meningitis and differential diagnosis between bacterial and aseptic meningitis with high sensitivity and specificity. Thus, hospitals should be encouraged to conduct TNF-α tests in CSF after lumbar puncture. © 2014 The Author(s) European Journal of Neurology © 2014 EAN.

Comparative Analysis of State Fish Consumption Advisories Targeting Sensitive Populations

PubMed Central

Scherer, Alison C.; Tsuchiya, Ami; Younglove, Lisa R.; Burbacher, Thomas M.; Faustman, Elaine M.

2008-01-01

Objective Fish consumption advisories are issued to warn the public of possible toxicological threats from consuming certain fish species. Although developing fetuses and children are particularly susceptible to toxicants in fish, fish also contain valuable nutrients. Hence, formulating advice for sensitive populations poses challenges. We conducted a comparative analysis of advisory Web sites issued by states to assess health messages that sensitive populations might access. Data sources We evaluated state advisories accessed via the National Listing of Fish Advisories issued by the U.S. Environmental Protection Agency. Data extraction We created criteria to evaluate advisory attributes such as risk and benefit message clarity. Data synthesis All 48 state advisories issued at the time of this analysis targeted children, 90% (43) targeted pregnant women, and 58% (28) targeted women of childbearing age. Only six advisories addressed single contaminants, while the remainder based advice on 2–12 contaminants. Results revealed that advisories associated a dozen contaminants with specific adverse health effects. Beneficial health effects of any kind were specifically associated only with omega-3 fatty acids found in fish. Conclusions These findings highlight the complexity of assessing and communicating information about multiple contaminant exposure from fish consumption. Communication regarding potential health benefits conferred by specific fish nutrients was minimal and focused primarily on omega-3 fatty acids. This overview suggests some lessons learned and highlights a lack of both clarity and consistency in providing the breadth of information that sensitive populations such as pregnant women need to make public health decisions about fish consumption during pregnancy. PMID:19079708

Highly sensitive detection of the group A Rotavirus using Apolipoprotein H-coated ELISA plates compared to quantitative real-time PCR.

PubMed

Adlhoch, Cornelia; Kaiser, Marco; Hoehne, Marina; Mas Marques, Andreas; Stefas, Ilias; Veas, Francisco; Ellerbrok, Heinz

2011-02-10

The principle of a capture ELISA is binding of specific capture antibodies (polyclonal or monoclonal) to the surface of a suitable 96 well plate. These immobilized antibodies are capable of specifically binding a virus present in a clinical sample. Subsequently, the captured virus is detected using a specific detection antibody. The drawback of this method is that a capture ELISA can only function for a single virus captured by the primary antibody. Human Apolipoprotein H (ApoH) or β2-glycoprotein 1 is able to poly-specifically bind viral pathogens. Replacing specific capture antibodies by ApoH should allow poly-specific capture of different viruses that subsequently could be revealed using specific detection antibodies. Thus, using a single capture ELISA format different viruses could be analysed depending on the detection antibody that is applied. In order to demonstrate that this is a valid approach we show detection of group A rotaviruses from stool samples as a proof of principle for a new method of capture ELISA that should also be applicable to other viruses. Stool samples of different circulating common human and potentially zoonotic group A rotavirus strains, which were pretested in commercial EIAs and genotyped by PCR, were tested in parallel in an ApoH-ELISA set-up and by quantitative real-time PCR (qPCR). Several control samples were included in the analysis. The ApoH-ELISA was suitable for the capture of rotavirus-particles and the detection down to 1,000 infectious units (TCID(50/ml)). Subsets of diagnostic samples of different G- and P-types were tested positive in the ApoH-ELISA in different dilutions. Compared to the qPCR results, the analysis showed high sensitivity, specificity and low cross-reactivity for the ApoH-ELISA, which was confirmed in receiver operating characteristics (ROC) analysis. In this study the development of a highly sensitive and specific capture ELISA was demonstrated by combining a poly-specific ApoH capture step with specific detection antibodies using group A rotaviruses as an example.

PREVALENCE OF METABOLIC SYNDROME IN YOUNG MEXICANS: A SENSITIVITY ANALYSIS ON ITS COMPONENTS.

PubMed

Murguía-Romero, Miguel; Jiménez-Flores, J Rafael; Sigrist-Flores, Santiago C; Tapia-Pancardo, Diana C; Jiménez-Ramos, Arnulfo; Méndez-Cruz, A René; Villalobos-Molina, Rafael

2015-07-28

obesity is a worldwide epidemic, and the high prevalence of diabetes type II (DM2) and cardiovascular disease (CVD) is in great part a consequence of that epidemic. Metabolic syndrome is a useful tool to estimate the risk of a young population to evolve to DM2 and CVD. to estimate the MetS prevalence in young Mexicans, and to evaluate each parameter as an independent indicator through a sensitivity analysis. the prevalence of MetS was estimated in 6 063 young of the México City metropolitan area. A sensitivity analysis was conducted to estimate the performance of each one of the components of MetS, as an indicator of the presence of MetS itself. Five statistical of the sensitivity analysis were calculated for each MetS component and the other parameters included: sensitivity, specificity, positive predictive value or precision, negative predictive value, and accuracy. the prevalence of MetS in Mexican young population was estimated to be 13.4%. Waist circumference presented the highest sensitivity (96.8% women; 90.0% men), blood pressure presented the highest specificity for women (97.7%) and glucose for men (91.0%). When all the five statistical are considered triglycerides is the component with the highest values, showing a value of 75% or more in four of them. Differences by sex are detected for averages of all components of MetS in young without alterations. Mexican young are highly prone to acquire MetS: 71% have at least one and up to five MetS parameters altered, and 13.4% of them have MetS. From all the five components of MetS, waist circumference presented the highest sensitivity as a predictor of MetS, and triglycerides is the best parameter if a single factor is to be taken as sole predictor of MetS in Mexican young population, triglycerides is also the parameter with the highest accuracy. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Smelling the Diagnosis: The Electronic Nose as Diagnostic Tool in Inflammatory Arthritis. A Case-Reference Study.

PubMed

Brekelmans, Marjolein P; Fens, Niki; Brinkman, Paul; Bos, Lieuwe D; Sterk, Peter J; Tak, Paul P; Gerlag, Daniëlle M

2016-01-01

To investigate whether exhaled breath analysis using an electronic nose can identify differences between inflammatory joint diseases and healthy controls. In a cross-sectional study, the exhaled breath of 21 rheumatoid arthritis (RA) and 18 psoriatic arthritis (PsA) patients with active disease was compared to 21 healthy controls using an electronic nose (Cyranose 320; Smiths Detection, Pasadena, CA, USA). Breathprints were analyzed with principal component analysis, discriminant analysis, and area under curve (AUC) of receiver operating characteristics (ROC) curves. Volatile organic compounds (VOCs) were identified by gas chromatography and mass spectrometry (GC-MS), and relationships between breathprints and markers of disease activity were explored. Breathprints of RA patients could be distinguished from controls with an accuracy of 71% (AUC 0.75, 95% CI 0.60-0.90, sensitivity 76%, specificity 67%). Breathprints from PsA patients were separated from controls with 69% accuracy (AUC 0.77, 95% CI 0.61-0.92, sensitivity 72%, specificity 71%). Distinction between exhaled breath of RA and PsA patients exhibited an accuracy of 69% (AUC 0.72, 95% CI 0.55-0.89, sensitivity 71%, specificity 72%). There was a positive correlation in RA patients of exhaled breathprints with disease activity score (DAS28) and number of painful joints. GC-MS identified seven key VOCs that significantly differed between the groups. Exhaled breath analysis by an electronic nose may play a role in differential diagnosis of inflammatory joint diseases. Data from this study warrant external validation.

Diagnostic value of blood-derived microRNAs for schizophrenia: results of a meta-analysis and validation.

PubMed

Liu, Sha; Zhang, Fuquan; Wang, Xijin; Shugart, Yin Yao; Zhao, Yingying; Li, Xinrong; Liu, Zhifen; Sun, Ning; Yang, Chunxia; Zhang, Kerang; Yue, Weihua; Yu, Xin; Xu, Yong

2017-11-10

There is an increasing interest in searching biomarkers for schizophrenia (SZ) diagnosis, which overcomes the drawbacks inherent with the subjective diagnostic methods. MicroRNA (miRNA) fingerprints have been explored for disease diagnosis. We performed a meta-analysis to examine miRNA diagnostic value for SZ and further validated the meta-analysis results. Using following terms: schizophrenia/SZ, microRNA/miRNA, diagnosis, sensitivity and specificity, we searched databases restricted to English language and reviewed all articles published from January 1990 to October 2016. All extracted data were statistically analyzed and the results were further validated with peripheral blood mononuclear cells (PBMNCs) isolated from patients and healthy controls using RT-qPCR and receiver operating characteristic (ROC) analysis. A total of 6 studies involving 330 patients and 202 healthy controls were included for meta-analysis. The pooled sensitivity, specificity and diagnostic odds ratio were 0.81 (95% CI: 0.75-0.86), 0.81 (95% CI: 0.72-0.88) and 18 (95% CI: 9-34), respectively; the positive and negative likelihood ratio was 4.3 and 0.24 respectively; the area under the curve in summary ROC was 0.87 (95% CI: 0.84-0.90). Validation revealed that miR-181b-5p, miR-21-5p, miR-195-5p, miR-137, miR-346 and miR-34a-5p in PBMNCs had high diagnostic sensitivity and specificity in the context of schizophrenia. In conclusion, blood-derived miRNAs might be promising biomarkers for SZ diagnosis.

Enhanced sensitivity in detection of antiviral antibody responses using biotinylation of foot-and-mouth disease virus (FMDV) capsids

USDA-ARS?s Scientific Manuscript database

Analysis of the immune response to infection of livestock by foot-and-mouth disease virus (FMDV) is most often reported as the serum antibody response to the virus. While measurement of neutralizing antibody has been sensitive and specific, measurements of the quality of the antibody response are le...

Detection of Echinococcus multilocularis by MC-PCR: evaluation of diagnostic sensitivity and specificity without gold standard.

PubMed

Wahlström, Helene; Comin, Arianna; Isaksson, Mats; Deplazes, Peter

2016-01-01

A semi-automated magnetic capture probe-based DNA extraction and real-time PCR method (MC-PCR), allowing for a more efficient large-scale surveillance of Echinococcus multilocularis occurrence, has been developed. The test sensitivity has previously been evaluated using the sedimentation and counting technique (SCT) as a gold standard. However, as the sensitivity of the SCT is not 1, test characteristics of the MC-PCR was also evaluated using latent class analysis, a methodology not requiring a gold standard. Test results, MC-PCR and SCT, from a previous evaluation of the MC-PCR using 177 foxes shot in the spring (n=108) and autumn 2012 (n=69) in high prevalence areas in Switzerland were used. Latent class analysis was used to estimate the test characteristics of the MC-PCR. Although it is not the primary aim of this study, estimates of the test characteristics of the SCT were also obtained. This study showed that the sensitivity of the MC-PCR was 0.88 [95% posterior credible interval (PCI) 0.80-0.93], which was not significantly different than the SCT, 0.83 (95% PCI 0.76-0.88), which is currently considered as the gold standard. The specificity of both tests was high, 0.98 (95% PCI 0.94-0.99) for the MC-PCR and 0.99 (95% PCI 0.99-1) for the SCT. In a previous study, using fox scats from a low prevalence area, the specificity of the MC-PCR was higher, 0.999% (95% PCI 0.997-1). One reason for the lower estimate of the specificity in this study could be that the MC-PCR detects DNA from infected but non-infectious rodents eaten by foxes. When using MC-PCR in low prevalence areas or areas free from the parasite, a positive result in the MC-PCR should be regarded as a true positive. The sensitivity of the MC-PCR (0.88) was comparable to the sensitivity of SCT (0.83).

Diagnostic performance of HbA1c for diabetes in Arab vs. European populations: a systematic review and meta-analysis.

PubMed

Bertran, E A; Berlie, H D; Taylor, A; Divine, G; Jaber, L A

2017-02-01

To examine differences in the performance of HbA 1c for diagnosing diabetes in Arabs compared with Europeans. The PubMed, Embase and Cochrane library databases were searched for records published between 1998 and 2015. Estimates of sensitivity, specificity and log diagnostic odds ratios for an HbA 1c cut-point of 48 mmol/mol (6.5%) were compared between Arabs and Europeans, using a bivariate linear mixed-model approach. For studies reporting multiple cut-points, population-specific summary receiver operating characteristic (SROC) curves were constructed. In addition, sensitivity, specificity and Youden Index were estimated for strata defined by HbA 1c cut-point and population type. Database searches yielded 1912 unique records; 618 full-text articles were reviewed. Fourteen studies met the inclusion criteria; hand-searching yielded three additional eligible studies. Three Arab (N = 2880) and 16 European populations (N = 49 127) were included in the analysis. Summary sensitivity and specificity for a HbA 1c cut-point of 48 mmol/mol (6.5%) in both populations were 42% (33-51%), and 97% (95-98%). There was no difference in area under SROC curves between Arab and European populations (0.844 vs. 0.847; P = 0.867), suggesting no difference in HbA 1c diagnostic accuracy between populations. Multiple cut-point summary estimates stratified by population suggest that Arabs have lower sensitivity and higher specificity at a HbA 1c cut-point of 44 mmol/mol (6.2%) compared with European populations. Estimates also suggest similar test performance at cut-points of 44 mmol/mol (6.2%) and 48 mmol/mol (6.5%) for Arabs. Given the low sensitivity of HbA 1c in the high-risk Arab American population, we recommend a combination of glucose-based and HbA 1c testing to ensure an accurate and timely diagnosis of diabetes. © 2016 Diabetes UK.

Diagnostic value of serum galactomannan, (1-3)-β-D-glucan, and Aspergillus fumigatus-specific IgA and IgG assays for invasive pulmonary aspergillosis in non-neutropenic patients.

PubMed

Dobias, R; Jaworska, P; Tomaskova, H; Kanova, M; Lyskova, P; Vrba, Z; Holub, C; Svobodová, L; Hamal, P; Raska, M

2018-03-25

Detection of serum galactomannan (GM) and (1-3)-β-D-glucan (BG) is considered useful for non-culture diagnosis of invasive pulmonary aspergillosis (IPA) in neutropenic patients. Only few studies evaluated these seromarkers in non-neutropenic patients suspected of having IPA. The aim of this study was to evaluate both tests together with the Aspergillus fumigatus-specific serum IgG and IgA (IgAG) test for serological IPA diagnosis in non-neutropenic patients.Sera from 87 patients suspected of having IPA were retrospectively analyzed. Patients were categorized into groups of proven IPA (n=10), putative IPA (n=31), and non-IPA colonization (n=46). When the GM, BG, and IgAG assays were used for patients included in the study, the sensitivity/specificity / positive predictive value (PPV) / negative predictive value (NPV) were 48.8%/91.3%/83.3%/66.7%, 82.9%/73.9%/73.9%/82.9%, and 75.6%/95.7%/93.9%/81.5%, respectively. Thus, the highest specificity and PPV were confirmed for the IgAG assay. Improvements in the sensitivity and NPV were achieved by "at least one positive" analysis with the GM and BG assays, with the sensitivity/specificity/PPV/NPV values being 85.0%/69.6%/71.4%/84.2%. Nevertheless, the highest sensitivity and NPV were achieved by the "at least one positive" analysis combining the GM, BG, and IgAG tests (97.6% and 96.8%, respectively).The involvement of the IgAG assay could improve IPA diagnosis in non-neutropenic patients by increasing the sensitivity and NPV when combined with the GM or BG assays. Further improvement was achieved by combining the GM, BG, and IgAG assays using the "at least one positive test" strategy, especially if doubt exists. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Validation and Comparison of Accelerometers Worn on the Hip, Thigh, and Wrists for Measuring Physical Activity and Sedentary Behavior.

PubMed

Montoye, Alexander H K; Pivarnik, James M; Mudd, Lanay M; Biswas, Subir; Pfeiffer, Karin A

2016-01-01

Recent evidence suggests that physical activity (PA) and sedentary behavior (SB) exert independent effects on health. Therefore, measurement methods that can accurately assess both constructs are needed. To compare the accuracy of accelerometers placed on the hip, thigh, and wrists, coupled with machine learning models, for measurement of PA intensity category (SB, light-intensity PA [LPA], and moderate- to vigorous-intensity PA [MVPA]) and breaks in SB. Forty young adults (21 female; age 22.0 ± 4.2 years) participated in a 90-minute semi-structured protocol, performing 13 activities (three sedentary, 10 non-sedentary) for 3-10 minutes each. Participants chose activity order, duration, and intensity. Direct observation (DO) was used as a criterion measure of PA intensity category, and transitions from SB to a non-sedentary activity were breaks in SB. Participants wore four accelerometers (right hip, right thigh, and both wrists), and a machine learning model was created for each accelerometer to predict PA intensity category. Sensitivity and specificity for PA intensity category classification were calculated and compared across accelerometers using repeated measures analysis of variance, and the number of breaks in SB was compared using repeated measures analysis of variance. Sensitivity and specificity values for the thigh-worn accelerometer were higher than for wrist- or hip-worn accelerometers, > 99% for all PA intensity categories. Sensitivity and specificity for the hip-worn accelerometer were 87-95% and 93-97%. The left wrist-worn accelerometer had sensitivities and specificities of > 97% for SB and LPA and 91-95% for MVPA, whereas the right wrist-worn accelerometer had sensitivities and specificities of 93-99% for SB and LPA but 67-84% for MVPA. The thigh-worn accelerometer had high accuracy for breaks in SB; all other accelerometers overestimated breaks in SB. Coupled with machine learning modeling, the thigh-worn accelerometer should be considered when objectively assessing PA and SB.

Analysis of 30 breast implant rupture cases.

PubMed

Tark, Kwan Chul; Jeong, Hii Sun; Roh, Tae Suk; Choi, Jong Woo

2005-01-01

Breast implants used for augmentation mammoplasty or breast reconstruction could rupture from various causes such as trauma or spontaneous failure. The objectives of this study were to investigate the relationships between the causes of implant rupture and the degree of capsular contracture, and then to evaluate the relative efficacies of specific signs on magnetic resonance imaging (MRI) known to be beneficial for diagnosing the rupture. A retrospective review identified patients with prosthetic implant rupture or impending rupture treated by the senior author. The 30 cases of implant rupture available for review were classified into two groups: intracapsular and extracapsular ruptures. The 30 cases of breast implant ruptures were analyzed with respect to the clinical symptoms and signs, the causes of rupture, the degree of capsular contracture, and therapeutic plans. Among the 30 cases, 14 patients who had undergone MRI during the diagnostic period were analyzed with respect to the relationships between MRI readings and operative findings. Spontaneous rupture of membranes was most common (80%), followed by failure because of trauma (7%) and valve or implant base (4%). The symptoms during implant rupture were contour deformity, palpated mass-like lesions, pain, and focal inflammation. According to the analysis of specific MRI signs, the sensitivity and specificity of the linguine sign were 87% and 100%, respectively, for intracapsular rupture. For extracapsular rupture, the sensitivity and specificity of the linguine sign were, respectively, 67% and 75%. The sensitivity and specificity of the rat-tail sign and tear drop sign were 14% and 50%, respectively. Breast implant rupture was correlated with the degree of capsular contracture in our study. Among the various specific MRI signs used in diagnosing the rupture, the linguine sign was reliable and had a high sensitivity and specificity, especially in cases of intracapsular rupture. On the other hand, the rat-tail and tear drop signs were nonspecific signs for diagnosing the rupture of breast implant.

Validation of a Low-Cost Paper-Based Screening Test for Sickle Cell Anemia

PubMed Central

Piety, Nathaniel Z.; Yang, Xiaoxi; Kanter, Julie; Vignes, Seth M.; George, Alex; Shevkoplyas, Sergey S.

2016-01-01

Background The high childhood mortality and life-long complications associated with sickle cell anemia (SCA) in developing countries could be significantly reduced with effective prophylaxis and education if SCA is diagnosed early in life. However, conventional laboratory methods used for diagnosing SCA remain prohibitively expensive and impractical in this setting. This study describes the clinical validation of a low-cost paper-based test for SCA that can accurately identify sickle trait carriers (HbAS) and individuals with SCA (HbSS) among adults and children over 1 year of age. Methods and Findings In a population of healthy volunteers and SCA patients in the United States (n = 55) the test identified individuals whose blood contained any HbS (HbAS and HbSS) with 100% sensitivity and 100% specificity for both visual evaluation and automated analysis, and detected SCA (HbSS) with 93% sensitivity and 94% specificity for visual evaluation and 100% sensitivity and 97% specificity for automated analysis. In a population of post-partum women (with a previously unknown SCA status) at a primary obstetric hospital in Cabinda, Angola (n = 226) the test identified sickle cell trait carriers with 94% sensitivity and 97% specificity using visual evaluation (none of the women had SCA). Notably, our test permits instrument- and electricity-free visual diagnostics, requires minimal training to be performed, can be completed within 30 minutes, and costs about $0.07 in test-specific consumable materials. Conclusions Our results validate the paper-based SCA test as a useful low-cost tool for screening adults and children for sickle trait and disease and demonstrate its practicality in resource-limited clinical settings. PMID:26735691

Diagnostic performance of an automated analysis software for the diagnosis of Alzheimer’s dementia with 18F FDG PET

PubMed Central

Partovi, Sasan; Yuh, Roger; Pirozzi, Sara; Lu, Ziang; Couturier, Spencer; Grosse, Ulrich; Schluchter, Mark D; Nelson, Aaron; Jones, Robert; O’Donnell, James K; Faulhaber, Peter

2017-01-01

The objective of this study was to assess the ability of a quantitative software-aided approach to improve the diagnostic accuracy of 18F FDG PET for Alzheimer’s dementia over visual analysis alone. Twenty normal subjects (M:F-12:8; mean age 80.6 years) and twenty mild AD subjects (M:F-12:8; mean age 70.6 years) with 18F FDG PET scans were obtained from the ADNI database. Three blinded readers interpreted these PET images first using a visual qualitative approach and then using a quantitative software-aided approach. Images were classified on two five-point scales based on normal/abnormal (1-definitely normal; 5-definitely abnormal) and presence of AD (1-definitely not AD; 5-definitely AD). Diagnostic sensitivity, specificity, and accuracy for both approaches were compared based on the aforementioned scales. The sensitivity, specificity, and accuracy for the normal vs. abnormal readings of all readers combined were higher when comparing the software-aided vs. visual approach (sensitivity 0.93 vs. 0.83 P = 0.0466; specificity 0.85 vs. 0.60 P = 0.0005; accuracy 0.89 vs. 0.72 P<0.0001). The specificity and accuracy for absence vs. presence of AD of all readers combined were higher when comparing the software-aided vs. visual approach (specificity 0.90 vs. 0.70 P = 0.0008; accuracy 0.81 vs. 0.72 P = 0.0356). Sensitivities of the software-aided and visual approaches did not differ significantly (0.72 vs. 0.73 P = 0.74). The quantitative software-aided approach appears to improve the performance of 18F FDG PET for the diagnosis of mild AD. It may be helpful for experienced 18F FDG PET readers analyzing challenging cases. PMID:28123864

Longer-Term Investigation of the Value of 18F-FDG-PET and Magnetic Resonance Imaging for Predicting the Conversion of Mild Cognitive Impairment to Alzheimer's Disease: A Multicenter Study.

PubMed

Inui, Yoshitaka; Ito, Kengo; Kato, Takashi

2017-01-01

The value of fluorine-18-fluorodeoxyglucose positron emission tomography (18F-FDG-PET) and magnetic resonance imaging (MRI) for predicting conversion of mild cognitive impairment (MCI) to Alzheimer's disease (AD) in longer-term is unclear. To evaluate longer-term prediction of MCI to AD conversion using 18F-FDG-PET and MRI in a multicenter study. One-hundred and fourteen patients with MCI were followed for 5 years. They underwent clinical and neuropsychological examinations, 18F-FDG-PET, and MRI at baseline. PET images were visually classified into predefined dementia patterns. PET scores were calculated as a semi quantitative index. For structural MRI, z-scores in medial temporal area were calculated by automated volume-based morphometry (VBM). Overall, 72% patients with amnestic MCI progressed to AD during the 5-year follow-up. The diagnostic accuracy of PET scores over 5 years was 60% with 53% sensitivity and 84% specificity. Visual interpretation of PET images predicted conversion to AD with an overall 82% diagnostic accuracy, 94% sensitivity, and 53% specificity. The accuracy of VBM analysis presented little fluctuation through 5 years and it was highest (73%) at the 5-year follow-up, with 79% sensitivity and 63% specificity. The best performance (87.9% diagnostic accuracy, 89.8% sensitivity, and 82.4% specificity) was with a combination identified using multivariate logistic regression analysis that included PET visual interpretation, educational level, and neuropsychological tests as predictors. 18F-FDG-PET visual assessment showed high performance for predicting conversion to AD from MCI, particularly in combination with neuropsychological tests. PET scores showed high diagnostic specificity. Structural MRI focused on the medial temporal area showed stable predictive value throughout the 5-year course.

Comparison of next-generation sequencing mutation profiling with BRAF and IDH1 mutation-specific immunohistochemistry.

PubMed

Jabbar, Kausar J; Luthra, Rajalakshmi; Patel, Keyur P; Singh, Rajesh R; Goswami, Rashmi; Aldape, Ken D; Medeiros, L Jeffrey; Routbort, Mark J

2015-04-01

Mutation-specific antibodies for BRAF V600E and IDH1 R132H offer convenient immunohistochemical (IHC) assays to detect these mutations in tumors. Previous studies using these antibodies have shown high sensitivity and specificity, but use in routine diagnosis with qualitative assessment has not been well studied. In this retrospective study, we reviewed BRAF and IDH1 mutation-specific IHC results compared with separately obtained clinical next-generation sequencing results. For 67 tumors with combined IDH1 IHC and mutation data, IHC was unequivocally reported as positive or negative in all cases. Sensitivity of IHC for IDH1 R132H was 98% and specificity was 100% compared with mutation status. Four IHC-negative samples showed non-R132H IDH1 mutations including R132C, R132G, and P127T. For 128 tumors with combined BRAF IHC and mutation data, IHC was positive in 33, negative in 82, and equivocal in 13 tumors. The sensitivity of IHC was 97% and specificity was 99% when including only unequivocally positive or negative results. If equivocal IHC cases were included in the analysis as negative, sensitivity fell to 81%. If equivocal cases were classified as positive, specificity dropped to 91%. Eight IHC-negative samples showed non-V600E BRAF mutations including V600K, N581I, V600M, and K601E. We conclude that IHC for BRAF V600E and IDH1 R132H is relatively sensitive and specific, but there is a discordance rate that is not trivial. In addition, a significant proportion of patients harbor BRAF non-V600E or IDH1 non-R132H mutations not detectable by IHC, potentially limiting utility of IHC screening for BRAF and IDH1 mutations.

Lipopolysaccharide Specific Immunochromatography Based Lateral Flow Assay for Serogroup Specific Diagnosis of Leptospirosis in India

PubMed Central

Vanithamani, Shanmugam; Shanmughapriya, Santhanam; Narayanan, Ramasamy; Raja, Veerapandian; Kanagavel, Murugesan; Sivasankari, Karikalacholan; Natarajaseenivasan, Kalimuthusamy

2015-01-01

Background Leptospirosis is a re-emerging infectious disease that is under-recognized due to low-sensitivity and cumbersome serological tests. MAT is the gold standard test and it is the only serogroup specific test used till date. Rapid reliable alternative serogroup specific tests are needed for surveillance studies to identify locally circulating serogroups in the study area. Methods/Principal Findings In the present investigation the serological specificity of leptospiral lipopolysaccharides (LPS) was evaluated by enzyme linked immunosorbent assay (ELISA), dot blot assay and rapid immunochromatography based lateral flow assay (ICG-LFA). Sera samples from 120 MAT positive cases, 174 cases with febrile illness other than leptospirosis, and 121 seronegative healthy controls were evaluated for the diagnostic sensitivity and specificity of the developed assays. LPS was extracted from five locally predominant circulating serogroups including: Australis (27.5%), Autumnalis (11.7%), Ballum (25.8%), Grippotyphosa (12.5%), Pomona (10%) and were used as antigens in the diagnostics to detect IgM antibodies in patients’ sera. The sensitivity observed by IgM ELISA and dot blot assay using various leptospiral LPS was >90% for homologous sera. Except for Ballum LPS, no other LPS showed cross-reactivity to heterologous sera. An attempt was made to develop LPS based ICG-LFA for rapid and sensitive serogroup specific diagnostics of leptospirosis. The developed ICG-LFA showed sensitivity in the range between 93 and 100% for homologous sera. The Wilcoxon analysis showed LPS based ICG-LFA did not differ significantly from the gold standard MAT (P>0.05). Conclusion The application of single array of LPS for serogroup specific diagnosis is first of its kind. The developed assay could potentially be evaluated and employed for as MAT alternative. PMID:26340095

Assessing sensitivity and specificity of the Manchester Triage System in the evaluation of acute coronary syndrome in adult patients in emergency care: a systematic review.

PubMed

Nishi, Fernanda Ayache; de Oliveira Motta Maia, Flávia; de Souza Santos, Itamar; de Almeida Lopes Monteiro da Cruz, Dina

2017-06-01

Triage is the first assessment and sorting process used to prioritize patients arriving in the emergency department (ED). As a triage tool, the Manchester Triage System (MTS) must have a high sensitivity to minimize the occurrence of under-triage, but must not compromise specificity to avoid the occurrence of overtriage. Sensitivity and specificity of the MTS can be calculated using the frequency of appropriately assigned clinical priority levels for patients presenting to the ED. However, although there are well established criteria for the prioritization of patients with suspected acute coronary syndrome (ACS), several studies have reported difficulties when evaluating patients with this condition. The objective of this review was to synthesize the best available evidence on assessing the sensitivity and specificity of the MTS for screening high-level priority adult patients presenting to the ED with ACS. The current review considered studies that evaluated the use of the MTS in the risk classification of adult patients in the ED. In this review, studies that investigated the priority level, as established by the MTS to screen patients under suspicion of ACS or the sensitivity and specificity of the MTS, for screening patients before the medical diagnosis of ACS were included. This review included both experimental and epidemiological study designs. The results were presented in a narrative synthesis. Six studies were appraised by the independent reviewers. All appraised studies enrolled a consecutive or random sample of patients and presented an overall moderate methodological quality, and all of them were included in this review. A total of 54,176 participants were included in the six studies. All studies were retrospective. Studies included in this review varied in content and data reporting. Only two studies reported sensitivity and specificity values or all the necessary data to calculate sensitivity and specificity. The remaining four studies presented either a sensitivity analysis or the number of true positives and false negatives. However, these four studies were conducted considering only data from patients diagnosed with ACS. Sensitivity values were relatively uniform among the studies: 0.70-0.80. A specificity of 0.59 was reported in the study including only patients with non-traumatic chest pain. On the other hand, in the study that included patients with any complaint, the specificity of MTS to screen patients with ACS was 0.97. The current review demonstrates that the MTS has a moderate sensitivity to evaluate patients with ACS. This may compromise time to treatment in the ED, an important variable in the prognosis of ACS. Atypical presentation of ACS, or high specificity, may also explain the moderate sensitivity demonstrated in this review. However, because of minimal data, it is not possible to confirm this hypothesis. It is difficult to determine the acceptable level of sensitivity or specificity to ensure that a certain triage system is safe.

Evaluation of a New Immunochromatography Technology Test (LDBio Diagnostics) To Detect Toxoplasma IgG and IgM: Comparison with the Routine Architect Technique

PubMed Central

Flori, Pierre; Delaunay, Edouard; Guillerme, Cécile; Charaoui, Sana; Raberin, Hélène; Hafid, Jamal; L'Ollivier, Coralie

2017-01-01

ABSTRACT A study comparing the ICT (immunochromatography technology) Toxoplasma IgG and IgM rapid diagnostic test (LDBio Diagnostics, France) with a fully automated system, Architect, was performed on samples from university hospitals of Marseille and Saint-Etienne. A total of 767 prospective sera and 235 selected sera were collected. The panels were selected to test various IgG and IgM parameters. The reference technique, Toxoplasma IgGII Western blot analysis (LDBio Diagnostics), was used to confirm the IgG results, and commercial kits Platelia Toxo IgM (Bio-Rad) and Toxo-ISAgA (bioMérieux) were used in Saint-Etienne and Marseille, respectively, as the IgM reference techniques. Sensitivity and specificity of the ICT and the Architect IgG assays were compared using a prospective panel. Sensitivity was 100% for the ICT test and 92.1% for Architect (cutoff at 1.6 IU/ml). The low-IgG-titer serum results confirmed that ICT sensitivity was superior to that of Architect. Specificity was 98.7% (ICT) and 99.8% (Architect IgG). The ICT test is also useful for detecting IgM without IgG and is both sensitive (100%) and specific (100%), as it can distinguish nonspecific IgM from specific Toxoplasma IgM. In comparison, IgM sensitivity and specificity on Architect are 96.1% and 99.6%, respectively (cutoff at 0.5 arbitrary units [AU]/ml). To conclude, this new test overcomes the limitations of automated screening techniques, which are not sensitive enough for IgG and lack specificity for IgM (rare IgM false-positive cases). PMID:28954897

The cut-off values of anthropometric variables for predicting mild cognitive impairment in Malaysian older adults: a large population based cross-sectional study.

PubMed

Won, Huiloo; Abdul, Manaf Zahara; Mat Ludin, Arimi Fitri; Omar, Mohd Azahadi; Razali, Rosdinom; Shahar, Suzana

2017-01-01

Older adults are at risk of mild cognitive impairment (MCI), and simple anthropometric measurements can be used to screen for this condition. Thus, the aim of this study was to explore the cut-off values of body mass index (BMI) and waist circumference (WC) for predicting the risk of MCI in older Malaysian adults. A total of 2,240 Malaysian older adults aged ≥60 years were recruited using multistage random sampling in a population based cross-sectional study. Receiver operating characteristic (ROC) curve was used to determine the cut-off values of BMI and WC with optimum sensitivity and specificity for the detection of MCI. Age, gender, years of education, smoking habit, alcohol consumption, depression, and medical conditions were used as confounding factors in this analysis. A BMI cut-off value of 26 kg/m 2 (area under the receiver operating characteristic curve [AUC] 0.725; sensitivity 90.5%; specificity 38.8%) was appropriate in identifying the risk of getting MCI in both men and women. The optimum WC cut-offs for likelihood of MCI were 90 cm (AUC 0.745; sensitivity 78.0%; specificity 59.8%) for men and 82 cm (AUC 0.714; sensitivity 84.3%; specificity 49.7%) for women. The optimum calf circumference (CC) cut-off values for identifying MCI were 29 cm (AUC 0.731; sensitivity 72.6%; specificity 61.1%) for men and 26 cm (AUC 0.598; sensitivity 79.1%; specificity 45.3%) for women. The cut-off values could be advocated and used as part of the screening of MCI among older Malaysian adults. There is a need to further determine the predictive values of these cut-off points on outcomes through longitudinal study design.

Brain metabolic pattern analysis using a magnetic resonance spectra classification software in experimental stroke.

PubMed

Jiménez-Xarrié, Elena; Davila, Myriam; Candiota, Ana Paula; Delgado-Mederos, Raquel; Ortega-Martorell, Sandra; Julià-Sapé, Margarida; Arús, Carles; Martí-Fàbregas, Joan

2017-01-13

Magnetic resonance spectroscopy (MRS) provides non-invasive information about the metabolic pattern of the brain parenchyma in vivo. The SpectraClassifier software performs MRS pattern-recognition by determining the spectral features (metabolites) which can be used objectively to classify spectra. Our aim was to develop an Infarct Evolution Classifier and a Brain Regions Classifier in a rat model of focal ischemic stroke using SpectraClassifier. A total of 164 single-voxel proton spectra obtained with a 7 Tesla magnet at an echo time of 12 ms from non-infarcted parenchyma, subventricular zones and infarcted parenchyma were analyzed with SpectraClassifier ( http://gabrmn.uab.es/?q=sc ). The spectra corresponded to Sprague-Dawley rats (healthy rats, n = 7) and stroke rats at day 1 post-stroke (acute phase, n = 6 rats) and at days 7 ± 1 post-stroke (subacute phase, n = 14). In the Infarct Evolution Classifier, spectral features contributed by lactate + mobile lipids (1.33 ppm), total creatine (3.05 ppm) and mobile lipids (0.85 ppm) distinguished among non-infarcted parenchyma (100% sensitivity and 100% specificity), acute phase of infarct (100% sensitivity and 95% specificity) and subacute phase of infarct (78% sensitivity and 100% specificity). In the Brain Regions Classifier, spectral features contributed by myoinositol (3.62 ppm) and total creatine (3.04/3.05 ppm) distinguished among infarcted parenchyma (100% sensitivity and 98% specificity), non-infarcted parenchyma (84% sensitivity and 84% specificity) and subventricular zones (76% sensitivity and 93% specificity). SpectraClassifier identified candidate biomarkers for infarct evolution (mobile lipids accumulation) and different brain regions (myoinositol content).

Home oximetry to screen for obstructive sleep apnoea in Down syndrome.

PubMed

Hill, Catherine M; Elphick, Heather E; Farquhar, Michael; Gringras, Paul; Pickering, Ruth M; Kingshott, Ruth N; Martin, Jane; Reynolds, Janine; Joyce, Anna; Gavlak, Johanna C; Evans, Hazel J

2018-05-14

Children with Down syndrome are at high risk of obstructive sleep apnoea (OSA) and screening is recommended. Diagnosis of OSA should be confirmed with multichannel sleep studies. We aimed to determine whether home pulse oximetry (HPO) discriminates children at high risk of OSA, who need further diagnostic multichannel sleep studies. Cross-sectional prospective study in a training sample recruited through three UK centres. Validation sample used single-centre retrospective analysis of clinical data. Children with Down syndrome aged 0.5-6 years. Diagnostic multichannel sleep study and HPO. Sensitivity and specificity of HPO to predict moderate-to-severe OSA. 161/202 children with Down syndrome met quality criteria for inclusion and 25 had OSA. In this training sample, the best HPO parameter predictors of OSA were the delta 12 s index >0.555 (sensitivity 92%, specificity 65%) and 3% oxyhaemoglobin (SpO 2 ) desaturation index (3% ODI)>6.15 dips/hour (sensitivity 92%, specificity 63%). Combining variables (delta 12 s index, 3% ODI, mean and minimum SpO 2 ) achieved sensitivity of 96% but reduced specificity to 52%. All predictors retained or improved sensitivity in a clinical validation sample of 50 children with variable loss of specificity, best overall was the delta 12 s index, a measure of baseline SpO 2 variability (sensitivity 92%; specificity 63%). HPO screening could halve the number of children with Down syndrome needing multichannel sleep studies and reduce the burden on children, families and health services alike. This approach offers a practical universal screening approach for OSA in Down syndrome that is accessible to the non-specialist paediatrician. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Verification bias: an under-recognized source of error in assessing the efficacy of MRI of the meniscii.

PubMed

Richardson, Michael L; Petscavage, Jonelle M

2011-11-01

The sensitivity and specificity of magnetic resonance imaging (MRI) for diagnosis of meniscal tears has been studied extensively, with tears usually verified by surgery. However, surgically unverified cases are often not considered in these studies, leading to verification bias, which can falsely increase the sensitivity and decrease the specificity estimates. Our study suggests that such bias may be very common in the meniscal MRI literature, and illustrates techniques to detect and correct for such bias. PubMed was searched for articles estimating sensitivity and specificity of MRI for meniscal tears. These were assessed for verification bias, deemed potentially present if a study included any patients whose MRI findings were not surgically verified. Retrospective global sensitivity analysis (GSA) was performed when possible. Thirty-nine of the 314 studies retrieved from PubMed specifically dealt with meniscal tears. All 39 included unverified patients, and hence, potential verification bias. Only seven articles included sufficient information to perform GSA. Of these, one showed definite verification bias, two showed no bias, and four others showed bias within certain ranges of disease prevalence. Only 9 of 39 acknowledged the possibility of verification bias. Verification bias is underrecognized and potentially common in published estimates of the sensitivity and specificity of MRI for the diagnosis of meniscal tears. When possible, it should be avoided by proper study design. If unavoidable, it should be acknowledged. Investigators should tabulate unverified as well as verified data. Finally, verification bias should be estimated; if present, corrected estimates of sensitivity and specificity should be used. Our online web-based calculator makes this process relatively easy. Copyright © 2011 AUR. Published by Elsevier Inc. All rights reserved.

Investigating the Predictive Value of Functional MRI to Appetitive and Aversive Stimuli: A Pattern Classification Approach.

PubMed

McCabe, Ciara; Rocha-Rego, Vanessa

2016-01-01

Dysfunctional neural responses to appetitive and aversive stimuli have been investigated as possible biomarkers for psychiatric disorders. However it is not clear to what degree these are separate processes across the brain or in fact overlapping systems. To help clarify this issue we used Gaussian process classifier (GPC) analysis to examine appetitive and aversive processing in the brain. 25 healthy controls underwent functional MRI whilst seeing pictures and receiving tastes of pleasant and unpleasant food. We applied GPCs to discriminate between the appetitive and aversive sights and tastes using functional activity patterns. The diagnostic accuracy of the GPC for the accuracy to discriminate appetitive taste from neutral condition was 86.5% (specificity = 81%, sensitivity = 92%, p = 0.001). If a participant experienced neutral taste stimuli the probability of correct classification was 92. The accuracy to discriminate aversive from neutral taste stimuli was 82.5% (specificity = 73%, sensitivity = 92%, p = 0.001) and appetitive from aversive taste stimuli was 73% (specificity = 77%, sensitivity = 69%, p = 0.001). In the sight modality, the accuracy to discriminate appetitive from neutral condition was 88.5% (specificity = 85%, sensitivity = 92%, p = 0.001), to discriminate aversive from neutral sight stimuli was 92% (specificity = 92%, sensitivity = 92%, p = 0.001), and to discriminate aversive from appetitive sight stimuli was 63.5% (specificity = 73%, sensitivity = 54%, p = 0.009). Our results demonstrate the predictive value of neurofunctional data in discriminating emotional and neutral networks of activity in the healthy human brain. It would be of interest to use pattern recognition techniques and fMRI to examine network dysfunction in the processing of appetitive, aversive and neutral stimuli in psychiatric disorders. Especially where problems with reward and punishment processing have been implicated in the pathophysiology of the disorder.

Cost Effectiveness of Field Trauma Triage among Injured Adults Served by Emergency Medical Services

PubMed Central

Newgard, Craig D; Yang, Zhuo; Nishijima, Daniel; McConnell, K John; Trent, Stacy; Holmes, James F; Daya, Mohamud; Mann, N Clay; Hsia, Renee Y; Rea, Tom; Wang, N Ewen; Staudenmayer, Kristan; Delgado, M Kit

2016-01-01

Background The American College of Surgeons Committee on Trauma sets national targets for the accuracy of field trauma triage at ≥ 95% sensitivity and ≥ 65% specificity, yet the cost-effectiveness of realizing these goals is unknown. We evaluated the cost-effectiveness of current field trauma triage practices compared to triage strategies consistent with the national targets. Study Design This was a cost-effectiveness analysis using data from 79,937 injured adults transported by 48 emergency medical services (EMS) agencies to 105 trauma and non-trauma hospitals in 6 regions of the Western U.S. from 2006 through 2008. Incremental differences in survival, quality adjusted life years (QALYs), costs, and the incremental cost-effectiveness ratio (ICER; costs per QALY gained) were estimated for each triage strategy over a 1-year and lifetime horizon using a decision analytic Markov model. We considered an ICER threshold of less than $100,000 to be cost-effective. Results For these 6 regions, a high sensitivity triage strategy consistent with national trauma policy (sensitivity 98.6%, specificity 17.1%) would cost $1,317,333 per QALY gained, while current triage practices (sensitivity 87.2%, specificity 64.0%) cost $88,000 per QALY gained compared to a moderate sensitivity strategy (sensitivity 71.2%, specificity 66.5%). Refining EMS transport patterns by triage status improved cost-effectiveness. At the trauma system level, a high-sensitivity triage strategy would save 3.7 additional lives per year at a 1-year cost of $8.78 million, while a moderate sensitivity approach would cost 5.2 additional lives and save $781,616 each year. Conclusions A high-sensitivity approach to field triage consistent with national trauma policy is not cost effective. The most cost effective approach to field triage appears closely tied to triage specificity and adherence to triage-based EMS transport practices. PMID:27178369

Comparative Sensitivity Analysis of Muscle Activation Dynamics

PubMed Central

Günther, Michael; Götz, Thomas

2015-01-01

We mathematically compared two models of mammalian striated muscle activation dynamics proposed by Hatze and Zajac. Both models are representative for a broad variety of biomechanical models formulated as ordinary differential equations (ODEs). These models incorporate parameters that directly represent known physiological properties. Other parameters have been introduced to reproduce empirical observations. We used sensitivity analysis to investigate the influence of model parameters on the ODE solutions. In addition, we expanded an existing approach to treating initial conditions as parameters and to calculating second-order sensitivities. Furthermore, we used a global sensitivity analysis approach to include finite ranges of parameter values. Hence, a theoretician striving for model reduction could use the method for identifying particularly low sensitivities to detect superfluous parameters. An experimenter could use it for identifying particularly high sensitivities to improve parameter estimation. Hatze's nonlinear model incorporates some parameters to which activation dynamics is clearly more sensitive than to any parameter in Zajac's linear model. Other than Zajac's model, Hatze's model can, however, reproduce measured shifts in optimal muscle length with varied muscle activity. Accordingly we extracted a specific parameter set for Hatze's model that combines best with a particular muscle force-length relation. PMID:26417379

Late-night salivary cortisol for diagnosis of Cushing's syndrome by liquid chromatography/tandem mass spectrometry assay.

PubMed

Erickson, Dana; Singh, Ravinder J; Sathananthan, Airani; Vella, Adrian; Bryant, Sandra C

2012-04-01

Late-night salivary cortisol (LNSC) measurements have been increasingly used by physicians as an initial diagnostic test for evaluation of patients with clinical suspicion of Cushing's syndrome (CS). Published studies include various numbers of cases, controls and importantly, various assay methods (vast majority various immunoassays), as well as various methods to generate cut-points. The retrospective study evaluated the diagnostic utility of LNSC measurements in 249 patients evaluated for possibility of CS because of various clinical conditions using liquid chromatography/tandem mass spectrometry method (LC-MS/MS). CS was confirmed in 47 patients (18·9%) and excluded in 202 (81·1%) patients at the time of analysis. Late-night salivary cortisol was abnormal or >2·8 nmol/l in 35 of 47 patients with CS; sensitivity of 74·5% and elevated in 20 of 202 patients who were found not to have CS; specificity 90·1%. Using receiver-operator characteristic statistics for calculation of the most optimal sensitivity and specificity, the cut-off based on this data was LNSC > 2·1 nmol/l with sensitivity of 83·0% and specificity of 84·2%. Analysis of data at one referral institution showed somewhat limited sensitivity of LNSC for diagnosis of CS using current reference ranges. © 2012 Blackwell Publishing Ltd.

Evaluation of ALK gene rearrangement in central nervous system metastases of non-small-cell lung cancer using two-step RT-PCR technique.

PubMed

Nicoś, M; Krawczyk, P; Wojas-Krawczyk, K; Bożyk, A; Jarosz, B; Sawicki, M; Trojanowski, T; Milanowski, J

2017-12-01

RT-PCR technique has showed a promising value as pre-screening method for detection of mRNA containing abnormal ALK sequences, but its sensitivity and specificity is still discussable. Previously, we determined the incidence of ALK rearrangement in CNS metastases of NSCLC using IHC and FISH methods. We evaluated ALK gene rearrangement using two-step RT-PCR method with EML4-ALK Fusion Gene Detection Kit (Entrogen, USA). The studied group included 145 patients (45 females, 100 males) with CNS metastases of NSCLC and was heterogeneous in terms of histology and smoking status. 21% of CNS metastases of NSCLC (30/145) showed presence of mRNA containing abnormal ALK sequences. FISH and IHC tests confirmed the presence of ALK gene rearrangement and expression of ALK abnormal protein in seven patients with positive result of RT-PCR analysis (4.8% of all patients, 20% of RT-PCR positive patients). RT-PCR method compared to FISH analysis achieved 100% of sensitivity and only 82.7% of specificity. IHC method compared to FISH method indicated 100% of sensitivity and 97.8% of specificity. In comparison to IHC, RT-PCR showed identical sensitivity with high number of false positive results. Utility of RT-PCR technique in screening of ALK abnormalities and in qualification patients for molecularly targeted therapies needs further validation.

[POSSIBILITIES OF APPLICATION OF MALDI-TOF MASS-SPECTROMETRY FOR STUDY OF CARBOHYDRATE-SPECIFIC RECEPTORS FOR DIAGNOSTIC BACTERIOPHAGE EL TOR].

PubMed

Telesmanich, N R; Goncharenko, E V; Chaika, S O; Chaika, I A; Telicheva, V O

2016-01-01

Study mechanisms of interaction of diagnostic bacteriophage El Tor with sensitive strain Vibrio cholerae El Tor 18507 using direct protein profiling, identification of constant and variable proteins, taking part in interaction of the phage and cell, as well as carbohydrate-specific phage receptors. . A commercial preparation of cholera diagnostic bacteriophage El Tor, strain V. cholerae El Tor 18507 were used. Effect of carbohydrates on bacteriophage activity was determined in experiments with phage by a classic and modified by us method. Protein profiles of the studied objects were studied using MSP-analysis method. Sucrose was shown to inhibit lytic activity of bacteriophage. Proteome profiles of El Tor bacteriophage and sensitive indicator strains were studied, identification of constant and variable proteins of the studied objects by MSP Peak-list program was carried out. Analysis of changes of profiles of phage and microbial cell during interaction with sucrose gave a basis for assuming, that sucrose in the mixture of culture-phage enters interaction namely with phage protein receptors, blocking receptors specific for cholera vibrio, that subsequently manifests in a sharp decrease of phage activity against the sensitive strain.

High-resolution melting analysis for noninvasive prenatal diagnosis of IVS-II-I (G-A) fetal DNA in minor beta-thalassemia mothers.

PubMed

Zafari, Mandana; Gill, Pooria; Kowsaryan, Mehrnoush; Alipour, Abbass; Banihashemi, Ali

2016-10-01

The high-resolution melting (HRM) technique is fast, effective and successful method for mutation detection. The aim of this study was to determine the sensitivity and specificity of the HRM method for detection of a paternally inherited mutation in a fetus as a noninvasive prenatal diagnosis of β-thalassemia. Genomic DNAs were prepared from 50 β-thalassemia minor couples whose pregnancy was at risk for homozygous β-thalassemia. Ten milliliters of the maternal blood from each pregnant woman were collected and after separating plasma stored at -80 °C until analysis. The extracted DNAs were analyzed by HRM real-time PCR for detection of IVS-II-I (G-A) as a paternally inherited mutation. The gold standard was the result of a chorionic villus sampling by a standard reverse dot blotting test. The sensitivity and specificity of HRM real-time PCR were 92.6% and 82.6%, respectively. Also, the positive and negative predictive values were 86.2% and 90.47%, respectively. HRM real-time PCR was a sensitive and specific method for determining the paternally inherited mutation in the fetus at risk with thalassemia major.

Flow cytometry shows added value in diagnosing lymphoma in brain biopsies.

PubMed

van der Meulen, Matthijs; Bromberg, Jacoline E C; Lam, King H; Dammers, Ruben; Langerak, Anton W; Doorduijn, Jeanette K; Kros, Johan M; van den Bent, Martin J; van der Velden, Vincent H J

2018-05-10

To assess the sensitivity, specificity and turnaround time of flow cytometric analysis on brain biopsies compared to histology plus immunohistochemistry analysis in tumors with clinical suspicion of lymphoma. All brain biopsies performed between 2010 and 2015 at our institution and analyzed by both immunohistochemistry and flow cytometry were included in this retrospective study. Immunohistochemistry was considered the gold standard. In a total of 77 biopsies from 71 patients, 49 lymphomas were diagnosed by immunohistochemistry, flow cytometry results were concordant in 71 biopsies (92,2%). We found a specificity and sensitivity of flow cytometry of 100% and 87,8%, respectively. The time between the biopsy and reporting the result (turnaround time) was significantly shorter for flow cytometry, compared to immunohistochemistry (median: 1 versus 5 days). Flow cytometry has a high specificity and can confirm the diagnosis of a lymphoma significantly faster than immunohistochemistry. This allows for rapid initiation of treatment in this highly aggressive tumor. However, since its sensitivity is less than 100%, we recommend to perform histology plus immunohistochemistry in parallel to flow cytometry. This article is protected by copyright. All rights reserved. © 2018 International Clinical Cytometry Society.

Meta-epidemiologic study showed frequent time trends in summary estimates from meta-analyses of diagnostic accuracy studies.

PubMed

Cohen, Jérémie F; Korevaar, Daniël A; Wang, Junfeng; Leeflang, Mariska M; Bossuyt, Patrick M

2016-09-01

To evaluate changes over time in summary estimates from meta-analyses of diagnostic accuracy studies. We included 48 meta-analyses from 35 MEDLINE-indexed systematic reviews published between September 2011 and January 2012 (743 diagnostic accuracy studies; 344,015 participants). Within each meta-analysis, we ranked studies by publication date. We applied random-effects cumulative meta-analysis to follow how summary estimates of sensitivity and specificity evolved over time. Time trends were assessed by fitting a weighted linear regression model of the summary accuracy estimate against rank of publication. The median of the 48 slopes was -0.02 (-0.08 to 0.03) for sensitivity and -0.01 (-0.03 to 0.03) for specificity. Twelve of 96 (12.5%) time trends in sensitivity or specificity were statistically significant. We found a significant time trend in at least one accuracy measure for 11 of the 48 (23%) meta-analyses. Time trends in summary estimates are relatively frequent in meta-analyses of diagnostic accuracy studies. Results from early meta-analyses of diagnostic accuracy studies should be considered with caution. Copyright © 2016 Elsevier Inc. All rights reserved.

PAX5 methylation detection by droplet digital PCR for ultra-sensitive deep surgical margins analysis of head and neck squamous cell carcinoma

PubMed Central

Hayashi, Masamichi; Guerrero-Preston, Rafael; Sidransky, David; Koch, Wayne M.

2015-01-01

Molecular deep surgical margin analysis has been shown to predict locoregional recurrences of head and neck squamous cell carcinoma (HNSCC). In order to improve the accuracy and versatility of the analysis, we used a highly tumor-specific methylation marker and highly sensitive detection technology to test DNA from surgical margins. Histologically cancer-negative deep surgical margin samples were prospectively collected from 82 eligible HNSCC surgeries by an imprinting procedure (n=75) and primary tissue collection (n=70). Bisulfite treated DNA from each sample was analyzed by both conventional quantitative methylation-specific polymerase chain reaction (QMSP) and QMSP by droplet digital PCR (ddQMSP) targeting PAX5 gene promoter methylation. The association between the presence of PAX5 methylation and locoregional recurrence free survival (LRFS) was evaluated. PAX5 methylation was found in 68.0% (51/75) of tumors in the imprint samples and 71.4% (50/70) in the primary tissue samples. Among cases which did not have postoperative radiation, (n=31 in imprint samples, n=29 in tissue samples), both conventional QMSP and ddQMSP revealed that PAX5 methylation positive margins was significantly associated with poor LRFS by univariate analysis. In particular, ddQMSP increased detection of the PAX5 marker from 29% to 71% in the non-radiated imprint cases. Also, PAX5 methylated imprint margins were an excellent predictor of poor LRFS (HR=3.89, 95%CI:1.19-17.52, P=0.023) by multivariate analysis. PAX5 methylation appears to be an excellent tumor-specific marker for molecular deep surgical margin analysis of HNSCC. Moreover, the ddQMSP assay displays increased sensitivity for methylation marker detection. PMID:26304463

Can histogram analysis of MR images predict aggressiveness in pancreatic neuroendocrine tumors?

PubMed

De Robertis, Riccardo; Maris, Bogdan; Cardobi, Nicolò; Tinazzi Martini, Paolo; Gobbo, Stefano; Capelli, Paola; Ortolani, Silvia; Cingarlini, Sara; Paiella, Salvatore; Landoni, Luca; Butturini, Giovanni; Regi, Paolo; Scarpa, Aldo; Tortora, Giampaolo; D'Onofrio, Mirko

2018-06-01

To evaluate MRI derived whole-tumour histogram analysis parameters in predicting pancreatic neuroendocrine neoplasm (panNEN) grade and aggressiveness. Pre-operative MR of 42 consecutive patients with panNEN >1 cm were retrospectively analysed. T1-/T2-weighted images and ADC maps were analysed. Histogram-derived parameters were compared to histopathological features using the Mann-Whitney U test. Diagnostic accuracy was assessed by ROC-AUC analysis; sensitivity and specificity were assessed for each histogram parameter. ADC entropy was significantly higher in G2-3 tumours with ROC-AUC 0.757; sensitivity and specificity were 83.3 % (95 % CI: 61.2-94.5) and 61.1 % (95 % CI: 36.1-81.7). ADC kurtosis was higher in panNENs with vascular involvement, nodal and hepatic metastases (p= .008, .021 and .008; ROC-AUC= 0.820, 0.709 and 0.820); sensitivity and specificity were: 85.7/74.3 % (95 % CI: 42-99.2 /56.4-86.9), 36.8/96.5 % (95 % CI: 17.2-61.4 /76-99.8) and 100/62.8 % (95 % CI: 56.1-100/44.9-78.1). No significant differences between groups were found for other histogram-derived parameters (p >.05). Whole-tumour histogram analysis of ADC maps may be helpful in predicting tumour grade, vascular involvement, nodal and liver metastases in panNENs. ADC entropy and ADC kurtosis are the most accurate parameters for identification of panNENs with malignant behaviour. • Whole-tumour ADC histogram analysis can predict aggressiveness in pancreatic neuroendocrine neoplasms. • ADC entropy and kurtosis are higher in aggressive tumours. • ADC histogram analysis can quantify tumour diffusion heterogeneity. • Non-invasive quantification of tumour heterogeneity can provide adjunctive information for prognostication.

The Effects of Instrumentation on Urine Cytology and CK-20 Analysis for the Detection of Bladder Cancer.

PubMed

Wegelin, Olivier; Bartels, Diny W M; Tromp, Ellen; Kuypers, Karel C; van Melick, Harm H E

2015-10-01

To evaluate the effects of cystoscopy on urine cytology and additional cytokeratin-20 (CK-20) staining in patients presenting with gross hematuria. For 83 patients presenting with gross hematuria, spontaneous and instrumented paired urine samples were analyzed. Three patients were excluded. Spontaneous samples were collected within 1 hour before cystoscopy, and the instrumented samples were tapped through the cystoscope. Subsequently, patients underwent cystoscopic evaluation and imaging of the urinary tract. If tumor suspicious lesions were found on cystoscopy or imaging, subjects underwent transurethral resection or ureterorenoscopy. Two blinded uropathological reviewers (DB, KK) evaluated 160 urine samples. Reference standards were results of cystoscopy, imaging, or histopathology. Thirty-seven patients (46.3%) underwent transurethral resection or ureterorenoscopy procedures. In 30 patients (37.5%) tumor presence was confirmed by histopathology. The specificity of urine analysis was significantly higher for spontaneous samples than instrumented samples for both cytology alone (94% vs 72%, P = .01) and for cytology combined with CK-20 analysis (98% vs 84%, P = .02). The difference in sensitivity between spontaneous and instrumented samples was not significant for both cytology alone (40% vs 53%) and combined with CK-20 analysis (67% vs 67%). The addition of CK-20 analysis to cytology significantly increases test sensitivity in spontaneous urine cytology (67% vs 40%, P = .03). Instrumentation significantly decreases specificity of urine cytology. This may lead to unnecessary diagnostic procedures. Additional CK-20 staining in spontaneous urine cytology significantly increases sensitivity but did not improve the already high specificity. We suggest performing urine cytology and CK-20 analysis on spontaneously voided urine. Copyright © 2015 Elsevier Inc. All rights reserved.

Hepatic MR imaging for in vivo differentiation of steatosis, iron deposition and combined storage disorder: single-ratio in/opposed phase analysis vs. dual-ratio Dixon discrimination.

PubMed

Bashir, Mustafa R; Merkle, Elmar M; Smith, Alastair D; Boll, Daniel T

2012-02-01

To assess whether in vivo dual-ratio Dixon discrimination can improve detection of diffuse liver disease, specifically steatosis, iron deposition and combined disease over traditional single-ratio in/opposed phase analysis. Seventy-one patients with biopsy-proven (17.7 ± 17.0 days) hepatic steatosis (n = 16), iron deposition (n = 11), combined deposition (n = 3) and neither disease (n = 41) underwent MR examinations. Dual-echo in/opposed-phase MR with Dixon water/fat reconstructions were acquired. Analysis consisted of: (a) single-ratio hepatic region-of-interest (ROI)-based assessment of in/opposed ratios; (b) dual-ratio hepatic ROI assessment of in/opposed and fat/water ratios; (c) computer-aided dual-ratio assessment evaluating all hepatic voxels. Disease-specific thresholds were determined; statistical analyses assessed disease-dependent voxel ratios, based on single-ratio (a) and dual-ratio (b and c) techniques. Single-ratio discrimination succeeded in identifying iron deposition (I/O(Ironthreshold)<0.88) and steatosis (I/O(Fatthreshold>1.15)) from normal parenchyma, sensitivity 70.0%; it failed to detect combined disease. Dual-ratio discrimination succeeded in identifying abnormal hepatic parenchyma (F/W(Normalthreshold)>0.05), sensitivity 96.7%; logarithmic functions for iron deposition (I/O(Irondiscriminator)e((F/W(Fat)-0.01)/0.48)) differentiated combined from isolated diseases, sensitivity 100.0%; computer-aided dual-ratio analysis was comparably sensitive but less specific, 90.2% vs. 97.6%. MR two-point-Dixon imaging using dual-ratio post-processing based on in/opposed and fat/water ratios improved in vivo detection of hepatic steatosis, iron deposition, and combined storage disease beyond traditional in/opposed analysis. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

A multi-model assessment of terrestrial biosphere model data needs

NASA Astrophysics Data System (ADS)

Gardella, A.; Cowdery, E.; De Kauwe, M. G.; Desai, A. R.; Duveneck, M.; Fer, I.; Fisher, R.; Knox, R. G.; Kooper, R.; LeBauer, D.; McCabe, T.; Minunno, F.; Raiho, A.; Serbin, S.; Shiklomanov, A. N.; Thomas, A.; Walker, A.; Dietze, M.

2017-12-01

Terrestrial biosphere models provide us with the means to simulate the impacts of climate change and their uncertainties. Going beyond direct observation and experimentation, models synthesize our current understanding of ecosystem processes and can give us insight on data needed to constrain model parameters. In previous work, we leveraged the Predictive Ecosystem Analyzer (PEcAn) to assess the contribution of different parameters to the uncertainty of the Ecosystem Demography model v2 (ED) model outputs across various North American biomes (Dietze et al., JGR-G, 2014). While this analysis identified key research priorities, the extent to which these priorities were model- and/or biome-specific was unclear. Furthermore, because the analysis only studied one model, we were unable to comment on the effect of variability in model structure to overall predictive uncertainty. Here, we expand this analysis to all biomes globally and a wide sample of models that vary in complexity: BioCro, CABLE, CLM, DALEC, ED2, FATES, G'DAY, JULES, LANDIS, LINKAGES, LPJ-GUESS, MAESPA, PRELES, SDGVM, SIPNET, and TEM. Prior to performing uncertainty analyses, model parameter uncertainties were assessed by assimilating all available trait data from the combination of the BETYdb and TRY trait databases, using an updated multivariate version of PEcAn's Hierarchical Bayesian meta-analysis. Next, sensitivity analyses were performed for all models across a range of sites globally to assess sensitivities for a range of different outputs (GPP, ET, SH, Ra, NPP, Rh, NEE, LAI) at multiple time scales from the sub-annual to the decadal. Finally, parameter uncertainties and model sensitivities were combined to evaluate the fractional contribution of each parameter to the predictive uncertainty for a specific variable at a specific site and timescale. Facilitated by PEcAn's automated workflows, this analysis represents the broadest assessment of the sensitivities and uncertainties in terrestrial models to date, and provides a comprehensive roadmap for constraining model uncertainties through model development and data collection.

Targeted Quantitation of Proteins by Mass Spectrometry

PubMed Central

2013-01-01

Quantitative measurement of proteins is one of the most fundamental analytical tasks in a biochemistry laboratory, but widely used immunochemical methods often have limited specificity and high measurement variation. In this review, we discuss applications of multiple-reaction monitoring (MRM) mass spectrometry, which allows sensitive, precise quantitative analyses of peptides and the proteins from which they are derived. Systematic development of MRM assays is permitted by databases of peptide mass spectra and sequences, software tools for analysis design and data analysis, and rapid evolution of tandem mass spectrometer technology. Key advantages of MRM assays are the ability to target specific peptide sequences, including variants and modified forms, and the capacity for multiplexing that allows analysis of dozens to hundreds of peptides. Different quantitative standardization methods provide options that balance precision, sensitivity, and assay cost. Targeted protein quantitation by MRM and related mass spectrometry methods can advance biochemistry by transforming approaches to protein measurement. PMID:23517332

Targeted quantitation of proteins by mass spectrometry.

PubMed

Liebler, Daniel C; Zimmerman, Lisa J

2013-06-04

Quantitative measurement of proteins is one of the most fundamental analytical tasks in a biochemistry laboratory, but widely used immunochemical methods often have limited specificity and high measurement variation. In this review, we discuss applications of multiple-reaction monitoring (MRM) mass spectrometry, which allows sensitive, precise quantitative analyses of peptides and the proteins from which they are derived. Systematic development of MRM assays is permitted by databases of peptide mass spectra and sequences, software tools for analysis design and data analysis, and rapid evolution of tandem mass spectrometer technology. Key advantages of MRM assays are the ability to target specific peptide sequences, including variants and modified forms, and the capacity for multiplexing that allows analysis of dozens to hundreds of peptides. Different quantitative standardization methods provide options that balance precision, sensitivity, and assay cost. Targeted protein quantitation by MRM and related mass spectrometry methods can advance biochemistry by transforming approaches to protein measurement.

An evaluation of computer-aided disproportionality analysis for post-marketing signal detection.

PubMed

Lehman, H P; Chen, J; Gould, A L; Kassekert, R; Beninger, P R; Carney, R; Goldberg, M; Goss, M A; Kidos, K; Sharrar, R G; Shields, K; Sweet, A; Wiholm, B E; Honig, P K

2007-08-01

To understand the value of computer-aided disproportionality analysis (DA) in relation to current pharmacovigilance signal detection methods, four products were retrospectively evaluated by applying an empirical Bayes method to Merck's post-marketing safety database. Findings were compared with the prior detection of labeled post-marketing adverse events. Disproportionality ratios (empirical Bayes geometric mean lower 95% bounds for the posterior distribution (EBGM05)) were generated for product-event pairs. Overall (1993-2004 data, EBGM05> or =2, individual terms) results of signal detection using DA compared to standard methods were sensitivity, 31.1%; specificity, 95.3%; and positive predictive value, 19.9%. Using groupings of synonymous labeled terms, sensitivity improved (40.9%). More of the adverse events detected by both methods were detected earlier using DA and grouped (versus individual) terms. With 1939-2004 data, diagnostic properties were similar to those from 1993 to 2004. DA methods using Merck's safety database demonstrate sufficient sensitivity and specificity to be considered for use as an adjunct to conventional signal detection methods.

Integrated analysis of rice transcriptomic and metabolomic responses to elevated night temperatures identifies sensitivity- and tolerance-related profiles.

PubMed

Glaubitz, Ulrike; Li, Xia; Schaedel, Sandra; Erban, Alexander; Sulpice, Ronan; Kopka, Joachim; Hincha, Dirk K; Zuther, Ellen

2017-01-01

Transcript and metabolite profiling were performed on leaves from six rice cultivars under high night temperature (HNT) condition. Six genes were identified as central for HNT response encoding proteins involved in transcription regulation, signal transduction, protein-protein interactions, jasmonate response and the biosynthesis of secondary metabolites. Sensitive cultivars showed specific changes in transcript abundance including abiotic stress responses, changes of cell wall-related genes, of ABA signaling and secondary metabolism. Additionally, metabolite profiles revealed a highly activated TCA cycle under HNT and concomitantly increased levels in pathways branching off that could be corroborated by enzyme activity measurements. Integrated data analysis using clustering based on one-dimensional self-organizing maps identified two profiles highly correlated with HNT sensitivity. The sensitivity profile included genes of the functional bins abiotic stress, hormone metabolism, cell wall, signaling, redox state, transcription factors, secondary metabolites and defence genes. In the tolerance profile, similar bins were affected with slight differences in hormone metabolism and transcription factor responses. Metabolites of the two profiles revealed involvement of GABA signaling, thus providing a link to the TCA cycle status in sensitive cultivars and of myo-inositol as precursor for inositol phosphates linking jasmonate signaling to the HNT response specifically in tolerant cultivars. © 2016 John Wiley & Sons Ltd.

High frequency QRS ECG predicts ischemic defects during myocardial perfusion imaging

NASA Technical Reports Server (NTRS)

2004-01-01

Changes in high frequency QRS components of the electrocardiogram (HF QRS ECG) (150-250 Hz) are more sensitive than changes in conventional ST segments for detecting myocardial ischemia. We investigated the accuracy of 12-lead HF QRS ECG in detecting ischemia during adenosine tetrofosmin myocardial perfusion imaging (MPI). 12-lead HF QRS ECG recordings were obtained from 45 patients before and during adenosine technetium-99 tetrofosmin MPI tests. Before the adenosine infusions, recordings of HF QRS were analyzed according to a morphological score that incorporated the number, type and location of reduced amplitude zones (RAZs) present in the 12 leads. During the adenosine infusions, recordings of HF QRS were analyzed according to the maximum percentage changes (in both the positive and negative directions) that occurred in root mean square (RMS) voltage amplitudes within the 12 leads. The best set of prospective HF QRS criteria had a sensitivity of 94% and a specificity of 83% for correctly identifying the MPI result. The sensitivity of simultaneous ST segment changes (18%) was significantly lower than that of any individual HF QRS criterion (P less than 0.00l). Analysis of 12-lead HF QRS ECG is highly sensitive and specific for detecting ischemic perfusion defects during adenosine MPI stress tests and significantly more sensitive than analysis of conventional ST segments.

High frequency QRS ECG predicts ischemic defects during myocardial perfusion imaging

NASA Technical Reports Server (NTRS)

Rahman, Atiar

2006-01-01

Background: Changes in high frequency QRS components of the electrocardiogram (HF QRS ECG) (150-250 Hz) are more sensitive than changes in conventional ST segments for detecting myocardial ischemia. We investigated the accuracy of 12-lead HF QRS ECG in detecting ischemia during adenosine tetrofosmin myocardial perfusion imaging (MPI). Methods and Results: 12-lead HF QRS ECG recordings were obtained from 45 patients before and during adenosine technetium-99 tetrofosmin MPI tests. Before the adenosine infusions, recordings of HF QRS were analyzed according to a morphological score that incorporated the number, type and location of reduced amplitude zones (RAZs) present in the 12 leads. During the adenosine infusions, recordings of HF QRS were analyzed according to the maximum percentage changes (in both the positive and negative directions) that occurred in root mean square (RMS) voltage amplitudes within the 12 leads. The best set of prospective HF QRS criteria had a sensitivity of 94% and a specificity of 83% for correctly identifying the MPI result. The sensitivity of simultaneous ST segment changes (18%) was significantly lower than that of any individual HF QRS criterion (P<0.001). Conclusions: Analysis of 12-lead HF QRS ECG is highly sensitive and specific for detecting ischemic perfusion defects during adenosine MPI stress tests and significantly more sensitive than analysis of conventional ST segments.

Adaptive smoothing based on Gaussian processes regression increases the sensitivity and specificity of fMRI data.

PubMed

Strappini, Francesca; Gilboa, Elad; Pitzalis, Sabrina; Kay, Kendrick; McAvoy, Mark; Nehorai, Arye; Snyder, Abraham Z

2017-03-01

Temporal and spatial filtering of fMRI data is often used to improve statistical power. However, conventional methods, such as smoothing with fixed-width Gaussian filters, remove fine-scale structure in the data, necessitating a tradeoff between sensitivity and specificity. Specifically, smoothing may increase sensitivity (reduce noise and increase statistical power) but at the cost loss of specificity in that fine-scale structure in neural activity patterns is lost. Here, we propose an alternative smoothing method based on Gaussian processes (GP) regression for single subjects fMRI experiments. This method adapts the level of smoothing on a voxel by voxel basis according to the characteristics of the local neural activity patterns. GP-based fMRI analysis has been heretofore impractical owing to computational demands. Here, we demonstrate a new implementation of GP that makes it possible to handle the massive data dimensionality of the typical fMRI experiment. We demonstrate how GP can be used as a drop-in replacement to conventional preprocessing steps for temporal and spatial smoothing in a standard fMRI pipeline. We present simulated and experimental results that show the increased sensitivity and specificity compared to conventional smoothing strategies. Hum Brain Mapp 38:1438-1459, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Development of a highly sensitive and specific immunoassay for enrofloxacin based on heterologous coating haptens.

PubMed

Wang, Zhanhui; Zhang, Huiyan; Ni, Hengjia; Zhang, Suxia; Shen, Jianzhong

2014-04-11

In the paper, an enzyme-linked immunosorbent immunoassay (ELISA) for detection of enrofloxacin was described using one new derivative of enrofloxacin as coating hapten, resulting in surprisingly high sensitivity and specificity. Incorporation of aminobutyric acid (AA) in the new derivative of enrofloxacin had decreased the IC50 of the ELISA for enrofloxacin from 1.3 μg L(-1) to as low as 0.07 μg L(-1). The assay showed neglect cross-reactivity for other fluoroquinolones but ofloxacin (8.23%), marbofloxacin (8.97%) and pefloxacin (7.29%). Analysis of enrofloxacin fortified chicken muscle showed average recoveries from 81 to 115%. The high sensitivity and specificity of the assay makes it a suitable screening method for the determination of low levels of enrofloxacin in chicken muscle without clean-up step. Copyright © 2014 Elsevier B.V. All rights reserved.

Multi-modal approach using Raman spectroscopy and optical coherence tomography for the discrimination of colonic adenocarcinoma from normal colon

PubMed Central

Ashok, Praveen C.; Praveen, Bavishna B.; Bellini, Nicola; Riches, Andrew; Dholakia, Kishan; Herrington, C. Simon

2013-01-01

We report a multimodal optical approach using both Raman spectroscopy and optical coherence tomography (OCT) in tandem to discriminate between colonic adenocarcinoma and normal colon. Although both of these non-invasive techniques are capable of discriminating between normal and tumour tissues, they are unable individually to provide both the high specificity and high sensitivity required for disease diagnosis. We combine the chemical information derived from Raman spectroscopy with the texture parameters extracted from OCT images. The sensitivity obtained using Raman spectroscopy and OCT individually was 89% and 78% respectively and the specificity was 77% and 74% respectively. Combining the information derived using the two techniques increased both sensitivity and specificity to 94% demonstrating that combining complementary optical information enhances diagnostic accuracy. These data demonstrate that multimodal optical analysis has the potential to achieve accurate non-invasive cancer diagnosis. PMID:24156073

Independent component analysis-based source-level hyperlink analysis for two-person neuroscience studies

NASA Astrophysics Data System (ADS)

Zhao, Yang; Dai, Rui-Na; Xiao, Xiang; Zhang, Zong; Duan, Lian; Li, Zheng; Zhu, Chao-Zhe

2017-02-01

Two-person neuroscience, a perspective in understanding human social cognition and interaction, involves designing immersive social interaction experiments as well as simultaneously recording brain activity of two or more subjects, a process termed "hyperscanning." Using newly developed imaging techniques, the interbrain connectivity or hyperlink of various types of social interaction has been revealed. Functional near-infrared spectroscopy (fNIRS)-hyperscanning provides a more naturalistic environment for experimental paradigms of social interaction and has recently drawn much attention. However, most fNIRS-hyperscanning studies have computed hyperlinks using sensor data directly while ignoring the fact that the sensor-level signals contain confounding noises, which may lead to a loss of sensitivity and specificity in hyperlink analysis. In this study, on the basis of independent component analysis (ICA), a source-level analysis framework is proposed to investigate the hyperlinks in a fNIRS two-person neuroscience study. The performance of five widely used ICA algorithms in extracting sources of interaction was compared in simulative datasets, and increased sensitivity and specificity of hyperlink analysis by our proposed method were demonstrated in both simulative and real two-person experiments.

Highly sensitive protein detection by biospecific AFM-based fishing with pulsed electrical stimulation.

PubMed

Pleshakova, Tatyana O; Malsagova, Kristina A; Kaysheva, Anna L; Kopylov, Arthur T; Tatur, Vadim Yu; Ziborov, Vadim S; Kanashenko, Sergey L; Galiullin, Rafael A; Ivanov, Yuri D

2017-08-01

We report here the highly sensitive detection of protein in solution at concentrations from 10 -15 to 10 -18 m using the combination of atomic force microscopy (AFM) and mass spectrometry. Biospecific detection of biotinylated bovine serum albumin was carried out by fishing out the protein onto the surface of AFM chips with immobilized avidin, which determined the specificity of the analysis. Electrical stimulation was applied to enhance the fishing efficiency. A high sensitivity of detection was achieved by application of nanosecond electric pulses to highly oriented pyrolytic graphite placed under the AFM chip. A peristaltic pump-based flow system, which is widely used in routine bioanalytical assays, was employed throughout the analysis. These results hold promise for the development of highly sensitive protein detection methods using nanosensor devices.

Colour Doppler analysis of ophthalmic vessels in the diagnosis of carotic artery and retinal vein occlusion, diabetic retinopathy and glaucoma: systematic review of test accuracy studies.

PubMed

Bittner, Mario; Faes, Livia; Boehni, Sophie C; Bachmann, Lucas M; Schlingemann, Reinier O; Schmid, Martin K

2016-12-07

Colour Doppler analysis of ophthalmic vessels has been proposed as a promising tool in the diagnosis of various eye diseases, but the available diagnostic evidence has not yet been assessed systematically. We performed a comprehensive systematic review of the literature on the diagnostic properties of Colour Doppler imaging (CDI) assessing ophthalmic vessels and provide an inventory of the available evidence. Eligible papers were searched electronically in (Pre) Medline, Embase and Scopus, and via cross-checking of reference lists. The minimum requirement to be included was the availability of original data and the possibility to construct a two-by-two table. Study selection, critical appraisal using the QUADAS II instrument and extraction of salient study characteristics was made in duplicate. Sensitivity and specificity was computed for each study. We included 11 studies (15 two-by-two tables) of moderate methodological quality enrolling 820 participants (range 30 to 118). In 44.4% participants were female (range 37-59% in specific subgroups). CDI was assessed for internal carotid stenosis, diabetic retinopathy, glaucoma, and branch or central retinal vein occlusion diagnosis. There was insufficient data to pool the results for specific illnesses. For the assessments of ophthalmic arteries, mean sensitivity was 0.69 (range 0.27-0.96) with a corresponding mean specificity of 0.83 (range 0.70-0.96). Mean sensitivity of the central retinal artery assessments was 0.58 (range 0.31-0.84) and the corresponding mean specificity was 0.82 (range 0.63-0.94). Robust assessments of the diagnostic value of colour Doppler analysis remain uncommon, limiting the possibilities to extrapolate its true potential for clinical practice. PROSPERO 2014:CRD42014014027.

A Retrospective Estimate of Ear Disease Detection Using the "Red Flags" in a Clinical Sample.

PubMed

Klyn, Niall A M; Kleindienst Robler, Samantha; Alfakir, Razan; Nielsen, Donald W; Griffith, James W; Carlson, Deborah L; Lundy, Larry; Dhar, Sumitrajit; Zapala, David A

2018-03-01

The purpose of this study was to evaluate the specificity and sensitivity of two red flag protocols in detecting ear diseases associated with changes in hearing. The presence of red-flag symptoms was determined in a chart review of 307 adult patients from the Mayo Clinic Florida Departments of Otorhinolaryngology and Audiology. Participants formed a convenience sample recruited for a separate study. Neurotologist diagnosis was the criterion for comparisons. Of the 251 patient files retained for analysis, 191 had one or more targeted diseases and 60 had age- or noise-related hearing loss. Food and Drug Administration red flags sensitivity was 91% (confidence interval [CI], 86 to 95%) and specificity was 72% (CI, 59 to 83%). American Academy of Otolaryngology-Head and Neck Surgery red flags sensitivity was 98% (CI, 95 to 99%) and specificity was 20% (CI, 11 to 32%). Stakeholders must determine which diseases are meaningful contraindications for hearing aid use and whether these red-flag protocols have acceptable levels of sensitivity and specificity. As direct-to-consumer models of hearing devices increase, a disease detection method that does not require provider intercession would be useful.

An Evaluation Study of Enzyme-Linked Immunosorbent Assay (ELISA) Using Recombinant Protein Pap31 for Detection of Antibody against Bartonella bacilliformis Infection among the Peruvian Population

PubMed Central

Angkasekwinai, Nasikarn; Atkins, Erin H.; Romero, Sofia; Grieco, John; Chao, Chien Chung; Ching, Wei Mei

2014-01-01

Reliable laboratory testing is of great importance to detect Bartonella bacilliformis infection. We evaluated the sensitivity and specificity of the enzyme-linked immunosorbent assay (ELISA) using recombinant protein Pap31 (rPap31) for the detection of antibodies against B. bacilliformis as compared with immunofluorescent assay (IFA). Of the 302 sera collected between 1997 and 2000 among an at-risk Peruvian population, 103 and 34 samples tested positive for IFA-immunoglobulin G (IgG) and IFA-IgM, respectively. By using Youden's index, the cutoff values of ELISA-IgG at 0.915 gave a sensitivity of 84.5% and specificity of 94%. The cutoff values of ELISA-IgM at 0.634 gave a sensitivity of 88.2% and specificity of 85.1%. Using latent class analysis, estimates of sensitivity and specificity of almost all the assays were slightly higher than those of a conventional method of calculation. The test is proved beneficial for discriminating between infected and non-infected individuals with the advantage of low-cost and high-throughput capability. PMID:24515944

Paired comparison of the sensitivity and specificity of multispectral digital skin lesion analysis and reflectance confocal microscopy in the detection of melanoma in vivo: A cross-sectional study.

PubMed

Song, Eunice; Grant-Kels, Jane M; Swede, Helen; D'Antonio, Jody L; Lachance, Avery; Dadras, Soheil S; Kristjansson, Arni K; Ferenczi, Katalin; Makkar, Hanspaul S; Rothe, Marti J

2016-12-01

Several technologies have been developed to aid dermatologists in the detection of melanoma in vivo including dermoscopy, multispectral digital skin lesion analysis (MDSLA), and reflectance confocal microscopy (RCM). To our knowledge, there have been no studies directly comparing MDSLA and RCM. We conducted a repeated measures analysis comparing the sensitivity and specificity of MDSLA and RCM in the detection of melanoma (n = 55 lesions from 36 patients). Study patients (n = 36) with atypical-appearing pigmented lesions (n = 55) underwent imaging by both RCM and MDSLA. Lesions were biopsied and analyzed by histopathology. RCM exhibited superior test metrics (P = .001, McNemar test) compared with MDSLA. Respectively, sensitivity measures were 85.7% and 71.4%, and specificity rates were 66.7% and 25.0%. The sample size was relatively small and was collected from only one dermatologist's patient base; there was some degree of dermatopathologist interobserver variability; and only one confocalist performed the RCM image evaluations. RCM is a useful adjunct during clinical assessment of in vivo lesions suspicious for melanoma or those requiring re-excision because of high level of dysplasia or having features consistent with an atypical melanocytic nevus with severe cytologic atypia. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

Seizure semiology identifies patients with bilateral temporal lobe epilepsy.

PubMed

Loesch, Anna Mira; Feddersen, Berend; Tezer, F Irsel; Hartl, Elisabeth; Rémi, Jan; Vollmar, Christian; Noachtar, Soheyl

2015-01-01

Laterality in temporal lobe epilepsy is usually defined by EEG and imaging results. We investigated whether the analysis of seizure semiology including lateralizing seizure phenomena identifies bilateral independent temporal lobe seizure onset. We investigated the seizure semiology in 17 patients in whom invasive EEG-video-monitoring documented bilateral temporal seizure onset. The results were compared to 20 left and 20 right consecutive temporal lobe epilepsy (TLE) patients who were seizure free after anterior temporal lobe resection. The seizure semiology was analyzed using the semiological seizure classification with particular emphasis on the sequence of seizure phenomena over time and lateralizing seizure phenomena. Statistical analysis included chi-square test or Fisher's exact test. Bitemporal lobe epilepsy patients had more frequently different seizure semiology (100% vs. 40%; p<0.001) and significantly more often lateralizing seizure phenomena pointing to bilateral seizure onset compared to patients with unilateral TLE (67% vs. 11%; p<0.001). The sensitivity of identical vs. different seizure semiology for the identification of bilateral TLE was high (100%) with a specificity of 60%. Lateralizing seizure phenomena had a low sensitivity (59%) but a high specificity (89%). The combination of lateralizing seizure phenomena and different seizure semiology showed a high specificity (94%) but a low sensitivity (59%). The analysis of seizure semiology including lateralizing seizure phenomena adds important clinical information to identify patients with bilateral TLE. Copyright © 2014 Elsevier B.V. All rights reserved.

Clinical Evaluation of a Loop-Mediated Amplification Kit for Diagnosis of Imported Malaria

PubMed Central

Polley, Spencer D.; González, Iveth J.; Mohamed, Deqa; Daly, Rosemarie; Bowers, Kathy; Watson, Julie; Mewse, Emma; Armstrong, Margaret; Gray, Christen; Perkins, Mark D.; Bell, David; Kanda, Hidetoshi; Tomita, Norihiro; Kubota, Yutaka; Mori, Yasuyoshi; Chiodini, Peter L.; Sutherland, Colin J.

2013-01-01

Background. Diagnosis of malaria relies on parasite detection by microscopy or antigen detection; both fail to detect low-density infections. New tests providing rapid, sensitive diagnosis with minimal need for training would enhance both malaria diagnosis and malaria control activities. We determined the diagnostic accuracy of a new loop-mediated amplification (LAMP) kit in febrile returned travelers. Methods. The kit was evaluated in sequential blood samples from returned travelers sent for pathogen testing to a specialist parasitology laboratory. Microscopy was performed, and then malaria LAMP was performed using Plasmodium genus and Plasmodium falciparum–specific tests in parallel. Nested polymerase chain reaction (PCR) was performed on all samples as the reference standard. Primary outcome measures for diagnostic accuracy were sensitivity and specificity of LAMP results, compared with those of nested PCR. Results. A total of 705 samples were tested in the primary analysis. Sensitivity and specificity were 98.4% and 98.1%, respectively, for the LAMP P. falciparum primers and 97.0% and 99.2%, respectively, for the Plasmodium genus primers. Post hoc repeat PCR analysis of all 15 tests with discrepant results resolved 4 results in favor of LAMP, suggesting that the primary analysis had underestimated diagnostic accuracy. Conclusions. Malaria LAMP had a diagnostic accuracy similar to that of nested PCR, with a greatly reduced time to result, and was superior to expert microscopy. PMID:23633403

Space transportation architecture: Reliability sensitivities

NASA Technical Reports Server (NTRS)

Williams, A. M.

1992-01-01

A sensitivity analysis is given of the benefits and drawbacks associated with a proposed Earth to orbit vehicle architecture. The architecture represents a fleet of six vehicles (two existing, four proposed) that would be responsible for performing various missions as mandated by NASA and the U.S. Air Force. Each vehicle has a prescribed flight rate per year for a period of 31 years. By exposing this fleet of vehicles to a probabilistic environment where the fleet experiences failures, downtimes, setbacks, etc., the analysis involves determining the resiliency and costs associated with the fleet of specific vehicle/subsystem reliabilities. The resources required were actual observed data on the failures and downtimes associated with existing vehicles, data based on engineering judgement for proposed vehicles, and the development of a sensitivity analysis program.

The sensitivity and specificity of subjective memory complaints and the subjective memory rating scale, deterioration cognitive observee, mini-mental state examination, six-item screener and clock drawing test in dementia screening.

PubMed

Ramlall, S; Chipps, J; Bhigjee, A I; Pillay, B J

2013-01-01

The effectiveness of dementia screening depends on the availability of suitable screening tools with good sensitivity and specificity to confidently distinguish normal age-related cognitive decline from dementia. The aim of this study was to evaluate the discriminant validity of 7 screening measures for dementia. A sample of 140 participants aged ≥60 years living in a residential facility for the aged were assessed clinically and assigned caseness for dementia using the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revised diagnostic criteria. Sensitivity and specificity of a selection of the following screening measures were tested using receiver operating characteristic (ROC) analysis for individual and combined tests: the Mini-Mental State Examination (MMSE), Six-Item Screener (SIS), Subjective Memory Complaint, Subjective Memory Complaint Clinical (SMCC), Subjective Memory Rating Scale (SMRS), Deterioration Cognitive Observee (DECO) and the Clock Drawing Test (CDT). Using ROC analyses, the SMCC, MMSE and CDT were found to be 'moderately accurate' in screening for dementia with an area under the curve (AUC) >0.70. The AUCs for the SIS (0.526), SMRS (0.661) and DECO (0.687) classified these measures as being 'less accurate'. At recommended cutoff scores, the SMCC had a sensitivity of 90.9% and specificity of 45.7%; the MMSE had a sensitivity of 63.6% and a specificity of 76.0%, and the CDT had a sensitivity of 44.4% and a specificity of 88.9%. Combining the SMCC and MMSE did not improve their predictive power except for a modest increase when using the sequential rule. The SMCC is composed of valid screening questions that have high sensitivity, are simple to administer and ideal for administration at the community or primary health care level as a first level of 'rule-out' screening. The MMSE can be included at a second stage of screening at the general hospital level and the CDT in specialist clinical settings. Sequential use of the SMCC and MMSE will improve the specificity of the former and the sensitivity of the latter. Copyright © 2013 S. Karger AG, Basel.

Lupin sensitization and clinical allergy in food allergic children in Norway.

PubMed

Lindvik, Helene; Holden, Lise; Løvik, Martinus; Cvancarova, Milada; Halvorsen, Ragnhild

2008-01-01

The aim of the present pilot study was to investigate to what extent children in Norway sensitized to lupin had clinical lupin allergy, and to compare sensitization to lupin with sensitization to other legumes. Thirty-five children with food allergy referred to a national referral hospital were evaluated with skin prick test (SPT) and analysis of serum-specific IgE to lupin, peanut, pea and soy. The children with positive SPTs to lupin were offered oral food challenges with lupin flour. Fifteen children (43%) had positive SPT and 17 children (49%) had serum-specific IgE to lupin. Ten SPT-positive children underwent oral food challenges and one experienced an allergic reaction to lupin flour. This child was one of six challenged children with IgE antibodies to peanut >15 kU(A)/L. There was a strong relationship between positive SPT to lupin flour and positive SPT to soy and between positive SPT to lupin and specific IgE to soy, pea and peanut. Children with sensitization to lupin are not likely to have a clinical lupin allergy. Avoidance of lupin on the basis of lupin sensitization or peanut allergy would lead to unnecessarily strict diets. Food challenge is currently necessary to diagnose lupin allergy.

[Comparative research into sensitivity and specificity of immune-enzyme analysis with chemiluminescence and colorimetric detection for detecting antigens and antibodies to avian influenza viruses and newcastle disease].

PubMed

Vitkova, O N; Kapustina, T P; Mikhailova, V V; Safonov, G A; Vlasova, N N; Belousova, R V

2015-01-01

The goal of this work was to demonstrate the results of the development of the enzyme-linked immunosorbent tests with chemiluminescence detection and colorimetric detection of specific viral antigens and antibodies for identifying the avian influenza and the Newcastle disease viruses: high sensitivity and specificity of the immuno- chemiluminescence assay, which are 10-50 times higher than those of the ELISA colorimetric method. The high effectiveness of the results and the automation of the process of laboratory testing (using a luminometer) allow these methods to be recommended for including in primary screening tests for these infectious diseases.

Systematic Review and Meta-Analysis of CT Features for Differentiating Complicated and Uncomplicated Appendicitis.

PubMed

Kim, Hae Young; Park, Ji Hoon; Lee, Yoon Jin; Lee, Sung Soo; Jeon, Jong-June; Lee, Kyoung Ho

2018-04-01

Purpose To perform a systematic review and meta-analysis to identify computed tomographic (CT) features for differentiating complicated appendicitis in patients suspected of having appendicitis and to summarize their diagnostic accuracy. Materials and Methods Studies on diagnostic accuracy of CT features for differentiating complicated appendicitis (perforated or gangrenous appendicitis) in patients suspected of having appendicitis were searched in Ovid-MEDLINE, EMBASE, and the Cochrane Library. Overlapping descriptors used in different studies to denote the same image finding were subsumed under a single CT feature. Pooled diagnostic accuracy of the CT features was calculated by using a bivariate random effects model. CT features with pooled diagnostic odds ratios with 95% confidence intervals not including 1 were considered as informative. Results Twenty-three studies were included, and 184 overlapping descriptors for various CT findings were subsumed under 14 features. Of these, 10 features were informative for complicated appendicitis. There was a general tendency for these features to show relatively high specificity but low sensitivity. Extraluminal appendicolith, abscess, appendiceal wall enhancement defect, extraluminal air, ileus, periappendiceal fluid collection, ascites, intraluminal air, and intraluminal appendicolith showed pooled specificity greater than 70% (range, 74%-100%), but sensitivity was limited (range, 14%-59%). Periappendiceal fat stranding was the only feature that showed high sensitivity (94%; 95% confidence interval: 86%, 98%) but low specificity (40%; 95% confidence interval, 23%, 60%). Conclusion Ten informative CT features for differentiating complicated appendicitis were identified in this study, nine of which showed high specificity, but low sensitivity. © RSNA, 2017 Online supplemental material is available for this article.

Exploration of Analysis Methods for Diagnostic Imaging Tests: Problems with ROC AUC and Confidence Scores in CT Colonography

PubMed Central

Mallett, Susan; Halligan, Steve; Collins, Gary S.; Altman, Doug G.

2014-01-01

Background Different methods of evaluating diagnostic performance when comparing diagnostic tests may lead to different results. We compared two such approaches, sensitivity and specificity with area under the Receiver Operating Characteristic Curve (ROC AUC) for the evaluation of CT colonography for the detection of polyps, either with or without computer assisted detection. Methods In a multireader multicase study of 10 readers and 107 cases we compared sensitivity and specificity, using radiological reporting of the presence or absence of polyps, to ROC AUC calculated from confidence scores concerning the presence of polyps. Both methods were assessed against a reference standard. Here we focus on five readers, selected to illustrate issues in design and analysis. We compared diagnostic measures within readers, showing that differences in results are due to statistical methods. Results Reader performance varied widely depending on whether sensitivity and specificity or ROC AUC was used. There were problems using confidence scores; in assigning scores to all cases; in use of zero scores when no polyps were identified; the bimodal non-normal distribution of scores; fitting ROC curves due to extrapolation beyond the study data; and the undue influence of a few false positive results. Variation due to use of different ROC methods exceeded differences between test results for ROC AUC. Conclusions The confidence scores recorded in our study violated many assumptions of ROC AUC methods, rendering these methods inappropriate. The problems we identified will apply to other detection studies using confidence scores. We found sensitivity and specificity were a more reliable and clinically appropriate method to compare diagnostic tests. PMID:25353643

Exploration of analysis methods for diagnostic imaging tests: problems with ROC AUC and confidence scores in CT colonography.

PubMed

Mallett, Susan; Halligan, Steve; Collins, Gary S; Altman, Doug G

2014-01-01

Different methods of evaluating diagnostic performance when comparing diagnostic tests may lead to different results. We compared two such approaches, sensitivity and specificity with area under the Receiver Operating Characteristic Curve (ROC AUC) for the evaluation of CT colonography for the detection of polyps, either with or without computer assisted detection. In a multireader multicase study of 10 readers and 107 cases we compared sensitivity and specificity, using radiological reporting of the presence or absence of polyps, to ROC AUC calculated from confidence scores concerning the presence of polyps. Both methods were assessed against a reference standard. Here we focus on five readers, selected to illustrate issues in design and analysis. We compared diagnostic measures within readers, showing that differences in results are due to statistical methods. Reader performance varied widely depending on whether sensitivity and specificity or ROC AUC was used. There were problems using confidence scores; in assigning scores to all cases; in use of zero scores when no polyps were identified; the bimodal non-normal distribution of scores; fitting ROC curves due to extrapolation beyond the study data; and the undue influence of a few false positive results. Variation due to use of different ROC methods exceeded differences between test results for ROC AUC. The confidence scores recorded in our study violated many assumptions of ROC AUC methods, rendering these methods inappropriate. The problems we identified will apply to other detection studies using confidence scores. We found sensitivity and specificity were a more reliable and clinically appropriate method to compare diagnostic tests.

The Objective Identification and Quantification of Interstitial Lung Abnormalities in Smokers.

PubMed

Ash, Samuel Y; Harmouche, Rola; Ross, James C; Diaz, Alejandro A; Hunninghake, Gary M; Putman, Rachel K; Onieva, Jorge; Martinez, Fernando J; Choi, Augustine M; Lynch, David A; Hatabu, Hiroto; Rosas, Ivan O; Estepar, Raul San Jose; Washko, George R

2017-08-01

Previous investigation suggests that visually detected interstitial changes in the lung parenchyma of smokers are highly clinically relevant and predict outcomes, including death. Visual subjective analysis to detect these changes is time-consuming, insensitive to subtle changes, and requires training to enhance reproducibility. Objective detection of such changes could provide a method of disease identification without these limitations. The goal of this study was to develop and test a fully automated image processing tool to objectively identify radiographic features associated with interstitial abnormalities in the computed tomography scans of a large cohort of smokers. An automated tool that uses local histogram analysis combined with distance from the pleural surface was used to detect radiographic features consistent with interstitial lung abnormalities in computed tomography scans from 2257 individuals from the Genetic Epidemiology of COPD study, a longitudinal observational study of smokers. The sensitivity and specificity of this tool was determined based on its ability to detect the visually identified presence of these abnormalities. The tool had a sensitivity of 87.8% and a specificity of 57.5% for the detection of interstitial lung abnormalities, with a c-statistic of 0.82, and was 100% sensitive and 56.7% specific for the detection of the visual subtype of interstitial abnormalities called fibrotic parenchymal abnormalities, with a c-statistic of 0.89. In smokers, a fully automated image processing tool is able to identify those individuals who have interstitial lung abnormalities with moderate sensitivity and specificity. Copyright © 2017 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.

Coping with confounds in multivoxel pattern analysis: what should we do about reaction time differences? A comment on Todd, Nystrom & Cohen 2013.

PubMed

Woolgar, Alexandra; Golland, Polina; Bode, Stefan

2014-09-01

Multivoxel pattern analysis (MVPA) is a sensitive and increasingly popular method for examining differences between neural activation patterns that cannot be detected using classical mass-univariate analysis. Recently, Todd et al. ("Confounds in multivariate pattern analysis: Theory and rule representation case study", 2013, NeuroImage 77: 157-165) highlighted a potential problem for these methods: high sensitivity to confounds at the level of individual participants due to the use of directionless summary statistics. Unlike traditional mass-univariate analyses where confounding activation differences in opposite directions tend to approximately average out at group level, group level MVPA results may be driven by any activation differences that can be discriminated in individual participants. In Todd et al.'s empirical data, factoring out differences in reaction time (RT) reduced a classifier's ability to distinguish patterns of activation pertaining to two task rules. This raises two significant questions for the field: to what extent have previous multivoxel discriminations in the literature been driven by RT differences, and by what methods should future studies take RT and other confounds into account? We build on the work of Todd et al. and compare two different approaches to remove the effect of RT in MVPA. We show that in our empirical data, in contrast to that of Todd et al., the effect of RT on rule decoding is negligible, and results were not affected by the specific details of RT modelling. We discuss the meaning of and sensitivity for confounds in traditional and multivoxel approaches to fMRI analysis. We observe that the increased sensitivity of MVPA comes at a price of reduced specificity, meaning that these methods in particular call for careful consideration of what differs between our conditions of interest. We conclude that the additional complexity of the experimental design, analysis and interpretation needed for MVPA is still not a reason to favour a less sensitive approach. Copyright © 2014 Elsevier Inc. All rights reserved.

Performance of an automated electronic acute lung injury screening system in intensive care unit patients.

PubMed

Koenig, Helen C; Finkel, Barbara B; Khalsa, Satjeet S; Lanken, Paul N; Prasad, Meeta; Urbani, Richard; Fuchs, Barry D

2011-01-01

Lung protective ventilation reduces mortality in patients with acute lung injury, but underrecognition of acute lung injury has limited its use. We recently validated an automated electronic acute lung injury surveillance system in patients with major trauma in a single intensive care unit. In this study, we assessed the system's performance as a prospective acute lung injury screening tool in a diverse population of intensive care unit patients. Patients were screened prospectively for acute lung injury over 21 wks by the automated system and by an experienced research coordinator who manually screened subjects for enrollment in Acute Respiratory Distress Syndrome Clinical Trials Network (ARDSNet) trials. Performance of the automated system was assessed by comparing its results with the manual screening process. Discordant results were adjudicated blindly by two physician reviewers. In addition, a sensitivity analysis using a range of assumptions was conducted to better estimate the system's performance. The Hospital of the University of Pennsylvania, an academic medical center and ARDSNet center (1994-2006). Intubated patients in medical and surgical intensive care units. None. Of 1270 patients screened, 84 were identified with acute lung injury (incidence of 6.6%). The automated screening system had a sensitivity of 97.6% (95% confidence interval, 96.8-98.4%) and a specificity of 97.6% (95% confidence interval, 96.8-98.4%). The manual screening algorithm had a sensitivity of 57.1% (95% confidence interval, 54.5-59.8%) and a specificity of 99.7% (95% confidence interval, 99.4-100%). Sensitivity analysis demonstrated a range for sensitivity of 75.0-97.6% of the automated system under varying assumptions. Under all assumptions, the automated system demonstrated higher sensitivity than and comparable specificity to the manual screening method. An automated electronic system identified patients with acute lung injury with high sensitivity and specificity in diverse intensive care units of a large academic medical center. Further studies are needed to evaluate the effect of automated prompts that such a system can initiate on the use of lung protective ventilation in patients with acute lung injury.

PRospective Imaging of CErvical cancer and neoadjuvant treatment (PRICE) study: role of ultrasound to predict partial response in locally advanced cervical cancer patients undergoing chemoradiation and radical surgery.

PubMed

Testa, A C; Ferrandina, G; Moro, F; Pasciuto, T; Moruzzi, M C; De Blasis, I; Mascilini, F; Foti, E; Autorino, R; Collarino, A; Gui, B; Zannoni, G F; Gambacorta, M A; Valentini, A L; Rufini, V; Scambia, G

2018-05-01

Chemoradiation-based neoadjuvant treatment followed by radical surgery is an alternative therapeutic strategy for locally advanced cervical cancer (LACC), but ultrasound variables used to predict partial response to neoadjuvant treatment are not well defined. Our goal was to analyze prospectively the potential role of transvaginal ultrasound in early prediction of partial pathological response, assessed in terms of residual disease at histology, in a large, single-institution series of LACC patients triaged to neoadjuvant treatment followed by radical surgery. Between October 2010 and June 2014, we screened 108 women with histologically documented LACC Stage IB2-IVA, of whom 88 were included in the final analysis. Tumor volume, three-dimensional (3D) power Doppler indices and contrast parameters were obtained before (baseline examination) and after 2 weeks of treatment. The pathological response was defined as complete (absence of any residual tumor after treatment) or partial (microscopic and/or macroscopic residual tumor at pathological examination). Complete-response and partial-response groups were compared and receiver-operating characteristics (ROC) curves were generated for ultrasound variables that were statistically significant on univariate analysis to evaluate their diagnostic ability to predict partial pathological response. There was a complete pathological response to neoadjuvant therapy in 40 (45.5%) patients and a partial response in 48 (54.5%). At baseline examination, tumor volume did not differ between the two groups. However, after 2 weeks of neoadjuvant treatment, the tumor volume was significantly greater in patients with partial response than it was in those with complete response (P = 0.019). Among the 3D vascular indices, the vascularization index (VI) was significantly lower in the partial-response compared with the complete-response group, both before and after 2 weeks of treatment (P = 0.037 and P = 0.024, respectively). At baseline examination in the contrast analysis, women with partial response had lower tumor peak enhancement (PE) as well as lower tumor wash-in rate (WiR) and longer tumor rise time (RT) compared with complete responders (P = 0.006, P = 0.003, P = 0.038, respectively). There was no difference in terms of contrast parameters after 2 weeks of treatment. ROC-curve analysis of baseline parameters showed that the best cut-offs for predicting partial pathological response were 41.5% for VI (sensitivity, 63.6%; specificity, 66.7%); 16123.5 auxiliary units for tumor PE (sensitivity, 47.9%; specificity, 84.2%); 7.8 s for tumor RT (sensitivity, 68.8%; specificity, 57.9%); and 4902 for tumor WiR (sensitivity, 77.1%; specificity, 60.5%). ROC curves of parameters after 2 weeks of treatment showed that the best cut-off for predicting partial pathological response was 18.1 cm 3 for tumor volume (sensitivity, 70.8%; specificity 60.0%) and 39.5% for VI (sensitivity; 62.5%; specificity, 73.5%). Ultrasound and contrast parameters differ between LACC patients with complete response and those with partial response before and after 2 weeks of neoadjuvant treatment. However, neither ultrasound parameters before treatment nor those after 2 weeks of treatment had cut-off values with acceptable sensitivity and specificity for predicting partial pathological response to neoadjuvant therapy. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Which physical examination tests provide clinicians with the most value when examining the shoulder? Update of a systematic review with meta-analysis of individual tests.

PubMed

Hegedus, Eric J; Goode, Adam P; Cook, Chad E; Michener, Lori; Myer, Cortney A; Myer, Daniel M; Wright, Alexis A

2012-11-01

To update our previously published systematic review and meta-analysis by subjecting the literature on shoulder physical examination (ShPE) to careful analysis in order to determine each tests clinical utility. This review is an update of previous work, therefore the terms in the Medline and CINAHL search strategies remained the same with the exception that the search was confined to the dates November, 2006 through to February, 2012. The previous study dates were 1966 - October, 2006. Further, the original search was expanded, without date restrictions, to include two new databases: EMBASE and the Cochrane Library. The Quality Assessment of Diagnostic Accuracy Studies, version 2 (QUADAS 2) tool was used to critique the quality of each new paper. Where appropriate, data from the prior review and this review were combined to perform meta-analysis using the updated hierarchical summary receiver operating characteristic and bivariate models. Since the publication of the 2008 review, 32 additional studies were identified and critiqued. For subacromial impingement, the meta-analysis revealed that the pooled sensitivity and specificity for the Neer test was 72% and 60%, respectively, for the Hawkins-Kennedy test was 79% and 59%, respectively, and for the painful arc was 53% and 76%, respectively. Also from the meta-analysis, regarding superior labral anterior to posterior (SLAP) tears, the test with the best sensitivity (52%) was the relocation test; the test with the best specificity (95%) was Yergason's test; and the test with the best positive likelihood ratio (2.81) was the compression-rotation test. Regarding new (to this series of reviews) ShPE tests, where meta-analysis was not possible because of lack of sufficient studies or heterogeneity between studies, there are some individual tests that warrant further investigation. A highly specific test (specificity >80%, LR+ ≥ 5.0) from a low bias study is the passive distraction test for a SLAP lesion. This test may rule in a SLAP lesion when positive. A sensitive test (sensitivity >80%, LR- ≤ 0.20) of note is the shoulder shrug sign, for stiffness-related disorders (osteoarthritis and adhesive capsulitis) as well as rotator cuff tendinopathy. There are six additional tests with higher sensitivities, specificities, or both but caution is urged since all of these tests have been studied only once and more than one ShPE test (ie, active compression, biceps load II) has been introduced with great diagnostic statistics only to have further research fail to replicate the results of the original authors. The belly-off and modified belly press tests for subscapularis tendinopathy, bony apprehension test for bony instability, olecranon-manubrium percussion test for bony abnormality, passive compression for a SLAP lesion, and the lateral Jobe test for rotator cuff tear give reason for optimism since they demonstrated both high sensitivities and specificities reported in low bias studies. Finally, one additional test was studied in two separate papers. The dynamic labral shear may be sensitive for SLAP lesions but, when modified, be diagnostic of labral tears generally. Based on data from the original 2008 review and this update, the use of any single ShPE test to make a pathognomonic diagnosis cannot be unequivocally recommended. There exist some promising tests but their properties must be confirmed in more than one study. Combinations of ShPE tests provide better accuracy, but marginally so. These findings seem to provide support for stressing a comprehensive clinical examination including history and physical examination. However, there is a great need for large, prospective, well-designed studies that examine the diagnostic accuracy of the many aspects of the clinical examination and what combinations of these aspects are useful in differentially diagnosing pathologies of the shoulder.

[Sensitivity and specificity between the Composite International Diagnostic Interview Version 3.0 (World Mental Health, CIDI) and the Standardised Clinical Evaluation version I (SCID-I) in a mental health survey of the city of Medellin, 2012].

PubMed

Montoya Gonzalez, Laura Elisa; Restrepo Bernal, Diana Patricia; Mejía-Montoya, Roberto; Bareño-Silva, José; Sierra-Hincapié, Gloria; Torres de Galvis, Yolanda; Marulanda-Restrepo, Daniel; Gómez-Sierra, Natalia; Gaviria-Arbeláez, Silvia

2016-01-01

In order to address the mental health problems of the Colombian population it is necessary to have diagnostic tools (local and international) that are valid, easy to apply, and comparable. To compare the sensitivity and specificity between the CIDI 3.0 and the SCID-I for major depressive disorder, bipolar I and II disorder, and substance dependence disorder. Cross-sectional study comparing the life prevalence of three mental disorders in 100 subjects using the CIDI 3.0 and the SCID-I. The study was approved by the Institutional Ethics Committee. The two diagnostic interviews were performed that measured by sensitivity, specificity, positive predictive value and negative predictive value with confidence intervals of 95%. The SPSS version 21.0 software was used for data analysis. The median age was 43.5 years, with an interquartile interval of 30 years. The highest sensitivity (Se) and specificity (Sp) was observed for drug dependence diagnosis - with 80%, (95%CI, 34.94-100), and 98.46 (95%CI, 94.7-100), respectively. SCID-I and CIDI 3.0 showed different levels of sensitivity and specificity for the three disorders studied with: high for substance dependence disorder, moderate for bipolar disorder I and II, and low for major depressive disorder. Copyright © 2015 Asociación Colombiana de Psiquiatría. All rights reserved.

Diagnostic Accuracy of Abdominal Ultrasound for Diagnosis of Acute Appendicitis: Systematic Review and Meta-analysis.

PubMed

Giljaca, Vanja; Nadarevic, Tin; Poropat, Goran; Nadarevic, Vesna Stefanac; Stimac, Davor

2017-03-01

To determine the diagnostic accuracy of abdominal ultrasound (US) for the diagnosis of acute appendicitis (AA), in terms of sensitivity, specificity and post-test probabilities for positive and negative result. A systematic search of MEDLINE, Embase, The Cochrane library and Science Citation Index Expanded from January 1994 to October 2014 was performed. Two authors independently evaluated studies for inclusion, extracted data and performed analyses. The reference standard for evaluation of final diagnosis was pathohistological report on tissue obtained at appendectomy. Summary sensitivity, specificity and post-test probability of AA after positive and negative result of US with corresponding 95% confidence intervals (CI) were calculated. Out of 3306 references identified through electronic searches, 17 reports met the inclusion criteria, with 2841 included participants. The summary sensitivity and specificity of US for diagnosis of AA were 69% (95% CI 59-78%) and 81% (95% CI 73-88%), respectively. At the median pretest probability of AA of 76.4%, the post-test probability for a positive and negative result of US was 92% (95% CI 88-95%) and 55% (95% CI 46-63%), respectively. Abdominal ultrasound does not seem to have a role in the diagnostic pathway for diagnosis of AA in suspected patients. The summary sensitivity and specificity of US do not exceed that of physical examination. Patients that require additional diagnostic workup should be referred to more sensitive and specific diagnostic procedures, such as computed tomography.

Texture analysis of pulmonary parenchymateous changes related to pulmonary thromboembolism in dogs - a novel approach using quantitative methods.

PubMed

Marschner, C B; Kokla, M; Amigo, J M; Rozanski, E A; Wiinberg, B; McEvoy, F J

2017-07-11

Diagnosis of pulmonary thromboembolism (PTE) in dogs relies on computed tomography pulmonary angiography (CTPA), but detailed interpretation of CTPA images is demanding for the radiologist and only large vessels may be evaluated. New approaches for better detection of smaller thrombi include dual energy computed tomography (DECT) as well as computer assisted diagnosis (CAD) techniques. The purpose of this study was to investigate the performance of quantitative texture analysis for detecting dogs with PTE using grey-level co-occurrence matrices (GLCM) and multivariate statistical classification analyses. CT images from healthy (n = 6) and diseased (n = 29) dogs with and without PTE confirmed on CTPA were segmented so that only tissue with CT numbers between -1024 and -250 Houndsfield Units (HU) was preserved. GLCM analysis and subsequent multivariate classification analyses were performed on texture parameters extracted from these images. Leave-one-dog-out cross validation and receiver operator characteristic (ROC) showed that the models generated from the texture analysis were able to predict healthy dogs with optimal levels of performance. Partial Least Square Discriminant Analysis (PLS-DA) obtained a sensitivity of 94% and a specificity of 96%, while Support Vector Machines (SVM) yielded a sensitivity of 99% and a specificity of 100%. The models, however, performed worse in classifying the type of disease in the diseased dog group: In diseased dogs with PTE sensitivities were 30% (PLS-DA) and 38% (SVM), and specificities were 80% (PLS-DA) and 89% (SVM). In diseased dogs without PTE the sensitivities of the models were 59% (PLS-DA) and 79% (SVM) and specificities were 79% (PLS-DA) and 82% (SVM). The results indicate that texture analysis of CTPA images using GLCM is an effective tool for distinguishing healthy from abnormal lung. Furthermore the texture of pulmonary parenchyma in dogs with PTE is altered, when compared to the texture of pulmonary parenchyma of healthy dogs. The models' poorer performance in classifying dogs within the diseased group, may be related to the low number of dogs compared to texture variables, a lack of balanced number of dogs within each group or a real lack of difference in the texture features among the diseased dogs.

Microbial Diagnostic Microarrays for the Detection and Typing of Food- and Water-Borne (Bacterial) Pathogens

PubMed Central

Kostić, Tanja; Sessitsch, Angela

2011-01-01

Reliable and sensitive pathogen detection in clinical and environmental (including food and water) samples is of greatest importance for public health. Standard microbiological methods have several limitations and improved alternatives are needed. Most important requirements for reliable analysis include: (i) specificity; (ii) sensitivity; (iii) multiplexing potential; (iv) robustness; (v) speed; (vi) automation potential; and (vii) low cost. Microarray technology can, through its very nature, fulfill many of these requirements directly and the remaining challenges have been tackled. In this review, we attempt to compare performance characteristics of the microbial diagnostic microarrays developed for the detection and typing of food and water pathogens, and discuss limitations, points still to be addressed and issues specific for the analysis of food, water and environmental samples. PMID:27605332

Automatic detection of oesophageal intubation based on ventilation pressure waveforms shows high sensitivity and specificity in patients with pulmonary disease.

PubMed

Kalmar, Alain F; Absalom, Anthony; Rombouts, Pieter; Roets, Jelle; Dewaele, Frank; Verdonck, Pascal; Stemerdink, Arjanne; Zijlstra, Jan G; Monsieurs, Koenraad G

2016-08-01

Unrecognised endotracheal tube misplacement in emergency intubations has a reported incidence of up to 17%. Current detection methods have many limitations restricting their reliability and availability in these circumstances. There is therefore a clinical need for a device that is small enough to be practical in emergency situations and that can detect oesophageal intubation within seconds. In a first reported evaluation, we demonstrated an algorithm based on pressure waveform analysis, able to determine tube location with high reliability in healthy patients. The aim of this study was to validate the specificity of the algorithm in patients with abnormal pulmonary compliance, and to demonstrate the reliability of a newly developed small device that incorporates the technology. Intubated patients with mild to moderate lung injury, admitted to intensive care were included in the study. The device was connected to the endotracheal tube, and three test ventilations were performed in each patient. All diagnostic data were recorded on PC for subsequent specificity/sensitivity analysis. A total of 105 ventilations in 35 patients with lung injury were analysed. With the threshold D-value of 0.1, the system showed a 100% sensitivity and specificity to diagnose tube location. The algorithm retained its specificity in patients with decreased pulmonary compliance. We also demonstrated the feasibility to integrate sensors and diagnostic hardware in a small, portable hand-held device for convenient use in emergency situations. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

The validity and accuracy of MRI arthrogram in the assessment of painful articular disorders of the hip.

PubMed

Rajeev, Aysha; Tuinebreijer, Wim; Mohamed, Abdalla; Newby, Mike

2018-01-01

The assessment of a patient with chronic hip pain can be challenging. The differential diagnosis of intra-articular pathology causing hip pain can be diverse. These includes conditions such as osteoarthritis, fracture, and avascular necrosis, synovitis, loose bodies, labral tears, articular pathology and, femoro-acetabular impingement. Magnetic resonance imaging (MRI) arthrography of the hip has been widely used now for diagnosis of articular pathology of the hip. A retrospective analysis of 113 patients who had MRI arthrogram and who underwent hip arthroscopy was included in the study. The MRI arthrogram was performed using gadolinium injection and reported by a single radiologist. The findings were then compared to that found on arthroscopy. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy and 95% confidence interval were calculated for each pathology. Labral tear-sensitivity 84% (74.3-90.5), specificity 64% (40.7-82.8), PPV 91% (82.1-95.8), NPV 48% (29.5-67.5), accuracy 80%. Delamination -sensitivity 7% (0.8-22.1), specificity 98% (91.6-99.7), PPV 50% (6.8-93.2), NPV 74% (65.1-82.2) and accuracy 39%. Chondral changes-sensitivity 25% (13.3-38.9), specificity 83% (71.3-91.1), PPV 52% (30.6-73.2), NPV 59% (48.0-69.2) and accuracy 58%. Femoro-acetabular impingement (CAM deformity)-sensitivity 34% (19.6-51.4), specificity 83% (72.2-90.4), PPV 50% (29.9-70.1), NPV 71% (60.6-80.5) and accuracy 66%. Synovitis-sensitivity 11% (2.3-28.2), specificity 99% (93.6-100), PPV 75% (19.4-99.4), NPV 77% (68.1-84.6) and accuracy 77%. Our study conclusions are MRI arthrogram is a useful investigation tool in detecting labral tears, it is also helpful in the diagnosis of femoro-acetabular impingement. However, when it comes to the diagnosis of chondral changes, defects and cartilage delamination, the sensitivity and accuracy are low.

Evaluation of the GeneXpert MTB/RIF assay on extrapulmonary and respiratory samples other than sputum: a low burden country experience.

PubMed

Pandey, Sushil; Congdon, Jacob; McInnes, Bradley; Pop, Alina; Coulter, Christopher

2017-01-01

The aim of this study was to assess the performance of the GeneXpert MTB/RIF assay on extrapulmonary (EP) and respiratory (non-sputum) clinical samples of patients suspected of having tuberculosis (TB) from Queensland, Australia. A total of 269 EP and respiratory (non-sputum) clinical samples collected from Qld patients who were suspected of having TB were subjected to the GeneXpert MTB/RIF analysis, Ziehl-Neelsen (ZN) staining, Mycobacterium tuberculosis (MTB) culture and drug susceptibility testing. Phenotypic and genotypic data were compared. The overall performance analysis of the GeneXpert MTB/RIF assay for detection of MTB complex demonstrated sensitivity of 89%, specificity of 95%, PPV of 89% and NPV of 95% using culture as a reference standard. The GeneXpert MTB/RIF analysis of acid-fast bacilli (AFB) smear positive samples and AFB smear negative samples showed sensitivities of 100% and 77%, respectively. Looking at individual EP and respiratory (non-sputum) sample types, the sensitivity ranged from 60% to 100% although the specificity ranged from 33% to 100% with the specificity of lymph node tissue biopsy being the lowest. The GeneXpert MTB/RIF assay detected 11% more TB cases than culture and 27% more cases than ZN microscopy. Due to insufficient numbers of presenting rifampicin resistance cases, performance analysis of the GeneXpert MTB/RIF assay on rifampicin resistance could not be carried out. The GeneXpert MTB/RIF assay is potentially valuable for TB diagnosis in the majority of the EP and respiratory (other than sputum) samples in our setting. Although the GeneXpert MTB/RIF assay provides rapid diagnostic results, the overall sensitivity to rule out the disease is suboptimal for some specimen types. Performance varied according to specimen type and AFB smear status. The sensitivity and specificity of lymph node tissue was 63% and 33%. Care must be taken when using the GeneXpert MTB/RIF assay for detection of MTB in lymph node tissue samples. All samples should be cultured regardless of the GeneXpert MTB/RIF assay result. Copyright © 2016 Royal College of Pathologists of Australasia. Published by Elsevier B.V. All rights reserved.

Apolipoprotein E4 serum concentration for increased sensitivity and specificity of diagnosis of drug treated Alzheimer's disease patients vs. drug treated parkinson's disease patients vs. age-matched normal controls.

PubMed

Goldknopf, Ira L; Park, Helen R; Sabbagh, Marwan

2012-12-01

Inasmuch as Alzheimer's disease (AD) is difficult to diagnose, patients with suspected dementias are often given FDA approved medications, including donepezil, rivastigmine, memantine HCl, or a combination, prior to diagnosis, and some respond with improved cognition. The present study demonstrates how concentrations of a select group of serum protein biomarkers can provide the basis for sensitive and specific differential diagnosis of AD in drug treated patients. Optimization is addressed by taking into account whether the patients and controls have or do not have increased risk of AD die to the presence or absence of Apolipoprotein E4. For differential diagnosis of AD, prospectively collected newly drawn blood serum samples were obtained from drug treated Alzheimer's disease and Parkinson's disease patients from a first (39 drug treated DTAD, and 31 age matched normal controls) and second medical center (56 drug treated DTPD, 47 age-matched normal controls). Analytically validated quantitative 2D gel electrophoresis (%CV ≤ 20%; LOD ≥ 0.5 ng/spot, 300 μg/ml of blood serum) was employed with patient and control sera for differential diagnosis of AD. Protein quantitation was subjected to statistical analysis by single variable Dot, Box and Whiskers and Receiver Operator Characteristics (ROC) plots for individual biomarker performance, and multivariate linear discriminant analysis for joint performance of groups of biomarkers. Protein spots were identified and characterized by LC MS/MS of in-gel trypsin digests, amino acid sequence spans of the identified peptides, and the protein spot molecular weights and isoelectric points. The single variable statistical profiles of 58 individual protein biomarker concentrations of the DTAD patient group differed from those of the normal and/or the disease control groups. Multivariate linear discriminant analysis of blood serum concentrations of the 58 proteins distinguished drug treated Alzheimer's disease (DTAD) patients from drug treated Parkinson's disease (DTPD) patients and age matched normal controls (collectively not-DTAD, DTAD Sensitivity 87.2%, Not-DTAD Specificity 87.2). Moreover, when the patients and controls were stratified into carriers or non-carriers of Alzheimer's high risk Apolipoprotein E 4 allele and/or the Apolipoprotein E4 protein, the DTAD, DTPD and control Apo E4 (+) profiles were more divergent from one another than the corresponding Apo E4 (-) profiles. Multivariate stepwise linear discriminant analysis selected 17 of the 58 biomarkers as optimal and complimentary for distinguishing Apo E4 (+) DTAD patients from Apo E4 (+) DTPD and Apo E4 (+) controls (collectively Apo E4 (+) not-DTAD, DTAD Sensitivity 100%, not-DTAD Specificity 100%) and 22 of the 58 biomarkers for distinguishing Apo E4 (-) DTAD patients from Apo E4 (-) DTPD and Apo E4 (-) controls (collectively Apo E4 (-) not-DTAD, DTAD Sensitivity 94.4%, not- DTAD Specificity 94.4%). Only 6 of the selected proteins were common to both the Apo E4 (+) and the Apo E4 (-) discriminant functions. Recombining of the results of Apo E4 (+) and Apo E4 (-) discriminations provided overall sensitivity for total DTAD of 97.4% and specificity for total not-DTAD of 95.7%. These results can form the basis of a blood test for differential diagnosis of Alzheimer's disease patients already under treatment (DTAD) by anti dementia drugs, including donepezil, rivastigmine, memantine HCl, or a combination thereof. Also, the profile differences and the rise in specificity and sensitivity obtained by handling the Apo E4 (+) and Apo E4 (-) groups separately supports the concept that they are different patient and control populations in terms of the "normal" physiology, the pathophysiology of disease, and the response to drug treatment. Taking that into account enables increased sensitivity and specificity of differential diagnosis of Alzheimer's disease.

Biomarkers of gluten sensitivity in patients with non-affective psychosis: a meta-analysis.

PubMed

Lachance, Laura R; McKenzie, Kwame

2014-02-01

Dohan first proposed that there may be an association between gluten sensitivity and schizophrenia in the 1950s. Since then, this association has been measured using several different serum biomarkers of gluten sensitivity. At this point, it is unclear which serum biomarkers of gluten sensitivity are elevated in patients with schizophrenia. However, evidence suggests that the immune response in this group is different from the immune response to gluten found in patients with Celiac disease. A systematic literature review was performed to identify all original articles that measured biomarkers of gluten sensitivity in patients with schizophrenia and non-affective psychoses compared to a control group. Three databases were used: Ovid MEDLINE, Psych INFO, and Embase, dating back to 1946. Forward tracking and backward tracking were undertaken on retrieved papers. A meta-analysis was performed of specific biomarkers and reported according to MOOSE guidelines. 17 relevant original articles were identified, and 12 met criteria for the meta-analysis. Five biomarkers of gluten sensitivity were found to be significantly elevated in patients with non-affective psychoses compared to controls. The pooled odds ratio and 95% confidence intervals were Anti-Gliadin IgG OR=2.31 [1.16, 4.58], Anti-Gliadin IgA OR=2.57 [1.13, 5.82], Anti-TTG2 IgA OR=5.86 [2.88, 11.95], Anti-Gliadin (unspecified isotype) OR=7.68 [2.07, 28.42], and Anti-Wheat OR=2.74 [1.06, 7.08]. Four biomarkers for gluten sensitivity, Anti-EMA IgA, Anti-TTG2 IgG, Anti-DGP IgG, and Anti-Gluten were not found to be associated with schizophrenia. Not all serum biomarkers of gluten sensitivity are elevated in patients with schizophrenia. However, the specific immune response to gluten in this population differs from that found in patients with Celiac disease. Copyright © 2013 Elsevier B.V. All rights reserved.

Depression Case Finding in Individuals with Dementia: A Systematic Review and Meta-Analysis.

PubMed

Goodarzi, Zahra S; Mele, Bria S; Roberts, Derek J; Holroyd-Leduc, Jayna

2017-05-01

To compare the diagnostic accuracy of depression case finding tools with a criterion standard in the outpatient setting among adults with dementia. Systematic review and meta-analysis. Studies of older outpatients with dementia. Elderly outpatients (clinic and long-term care) with dementia (N = 3,035). Prevalence of major depression and diagnostic accuracy measures including sensitivity, specificity, and likelihood ratios. From the 11,539 citations, 20 studies were included for qualitative synthesis and 15 for a meta-analysis. Tools included were the Montgomery Åsberg Depression Rating Scale, Cornell Scale for Depression in Dementia (CSDD), Geriatric Depression Scale (GDS), Center for Epidemiologic Studies Depression Scale (CES-D), Hamilton Depression Rating Scale (HDRS), Single Question, Nijmegen Observer-Rated Depression Scale, and Even Briefer Assessment Scale-Depression. The pooled prevalence of depression in individuals with dementia was 30.3% (95% CI = 22.1-38.5). The average age was 75.2 (95% CI = 71.7-78.7), and mean Mini-Mental State Examination scores ranged from 11.2 to 24. The diagnostic accuracy of the individual tools was pooled for the best-reported cutoffs and for each cutoff, if available. The CSDD had a sensitivity of 0.84 (95% CI = 0.73-0.91) and a specificity of 0.80 (95% CI = 0.65-0.90), the 30-item GDS (GDS-30) had a sensitivity of 0.62 (95% CI = 0.45-0.76) and a specificity 0.81 (95% CI = 0.75-0.85), and the HDRS had a sensitivity of 0.86 (95% CI = 0.63-0.96) and a specificity of 0.84 (95% CI = 0.76-0.90). Summary statistics for all tools across best-reported cutoffs had significant heterogeneity. There are many validated tools for the detection of depression in individuals with dementia. Tools that incorporate a physician interview with patient and collateral histories, the CSDD and HDRS, have higher sensitivities, which would ensure fewer false-negatives. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.

Accuracy of mucocutaneous leishmaniasis diagnosis using polymerase chain reaction: systematic literature review and meta-analysis

PubMed Central

Gomes, Ciro Martins; Mazin, Suleimy Cristina; dos Santos, Elisa Raphael; Cesetti, Mariana Vicente; Bächtold, Guilherme Albergaria Brízida; Cordeiro, João Henrique de Freitas; Theodoro, Fabrício Claudino Estrela Terra; Damasco, Fabiana dos Santos; Carranza, Sebastián Andrés Vernal; Santos, Adriana de Oliveira; Roselino, Ana Maria; Sampaio, Raimunda Nonata Ribeiro

2015-01-01

The diagnosis of mucocutaneous leishmaniasis (MCL) is hampered by the absence of a gold standard. An accurate diagnosis is essential because of the high toxicity of the medications for the disease. This study aimed to assess the ability of polymerase chain reaction (PCR) to identify MCL and to compare these results with clinical research recently published by the authors. A systematic literature review based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses: the PRISMA Statement was performed using comprehensive search criteria and communication with the authors. A meta-analysis considering the estimates of the univariate and bivariate models was performed. Specificity near 100% was common among the papers. The primary reason for accuracy differences was sensitivity. The meta-analysis, which was only possible for PCR samples of lesion fragments, revealed a sensitivity of 71% [95% confidence interval (CI) = 0.59; 0.81] and a specificity of 93% (95% CI = 0.83; 0.98) in the bivariate model. The search for measures that could increase the sensitivity of PCR should be encouraged. The quality of the collected material and the optimisation of the amplification of genetic material should be prioritised. PMID:25946238

The glucose oxidase-peroxidase assay for glucose

USDA-ARS?s Scientific Manuscript database

The glucose oxidase-peroxidase assay for glucose has served as a very specific, sensitive, and repeatable assay for detection of glucose in biological samples. It has been used successfully for analysis of glucose in samples from blood and urine, to analysis of glucose released from starch or glycog...

Diagnostic accuracy of spot urinary protein and albumin to creatinine ratios for detection of significant proteinuria or adverse pregnancy outcome in patients with suspected pre-eclampsia: systematic review and meta-analysis

PubMed Central

Morris, R K; Riley, R D; Doug, M; Deeks, J J

2012-01-01

Objective To determine the diagnostic accuracy of two “spot urine” tests for significant proteinuria or adverse pregnancy outcome in pregnant women with suspected pre-eclampsia. Design Systematic review and meta-analysis. Data sources Searches of electronic databases 1980 to January 2011, reference list checking, hand searching of journals, and contact with experts. Inclusion criteria Diagnostic studies, in pregnant women with hypertension, that compared the urinary spot protein to creatinine ratio or albumin to creatinine ratio with urinary protein excretion over 24 hours or adverse pregnancy outcome. Study characteristics, design, and methodological and reporting quality were objectively assessed. Data extraction Study results relating to diagnostic accuracy were extracted and synthesised using multivariate random effects meta-analysis methods. Results Twenty studies, testing 2978 women (pregnancies), were included. Thirteen studies examining protein to creatinine ratio for the detection of significant proteinuria were included in the multivariate analysis. Threshold values for protein to creatinine ratio ranged between 0.13 and 0.5, with estimates of sensitivity ranging from 0.65 to 0.89 and estimates of specificity from 0.63 to 0.87; the area under the summary receiver operating characteristics curve was 0.69. On average, across all studies, the optimum threshold (that optimises sensitivity and specificity combined) seems to be between 0.30 and 0.35 inclusive. However, no threshold gave a summary estimate above 80% for both sensitivity and specificity, and considerable heterogeneity existed in diagnostic accuracy across studies at most thresholds. No studies looked at protein to creatinine ratio and adverse pregnancy outcome. For albumin to creatinine ratio, meta-analysis was not possible. Results from a single study suggested that the most predictive result, for significant proteinuria, was with the DCA 2000 quantitative analyser (>2 mg/mmol) with a summary sensitivity of 0.94 (95% confidence interval 0.86 to 0.98) and a specificity of 0.94 (0.87 to 0.98). In a single study of adverse pregnancy outcome, results for perinatal death were a sensitivity of 0.82 (0.48 to 0.98) and a specificity of 0.59 (0.51 to 0.67). Conclusion The maternal “spot urine” estimate of protein to creatinine ratio shows promising diagnostic value for significant proteinuria in suspected pre-eclampsia. The existing evidence is not, however, sufficient to determine how protein to creatinine ratio should be used in clinical practice, owing to the heterogeneity in test accuracy and prevalence across studies. Insufficient evidence is available on the use of albumin to creatinine ratio in this area. Insufficient evidence exists for either test to predict adverse pregnancy outcome. PMID:22777026

Cross-well slug testing in unconfined aquifers: A case study from the Sleepers River Watershed, Vermont

USGS Publications Warehouse

Belitz, K.; Dripps, W.

1999-01-01

Normally, slug test measurements are limited to the well in which the water level is perturbed. Consequently, it is often difficult to obtain reliable estimates of hydraulic properties, particularly if the aquifer is anisotropic or if there is a wellbore skin. In this investigation, we use partially penetrating stress and observation wells to evaluate specific storage, radial hydraulic conductivity and anisotropy of the aquifer, and the hydraulic conductivity of the borehole skin. The study site is located in the W9 subbasin of the Sleepers River Research Watershed, Vermont. At the site, ~3 m of saturated till are partially penetrated by a stress well located in the center of the unconfined aquifer and six observation wells located above, below, and at the depth of the stress well at radial distances of 1.2 and 2.4 m. The observation wells were shut in with inflatable packers. The semianalytical solution of Butler (1995) was used to conduct a sensitivity analysis and to interpret slug test results. The sensitivity analysis indicates that the response of the stress well is primarily sensitive to radial hydraulic conductivity, less sensitive to anisotropy and the conductivity of the borehole skin, and nearly insensitive to specific storage. In contrast, the responses of the observation wells are sensitive to all four parameters. Interpretation of the field data was facilitated by generating type curves in a manner analogous to the method of Cooper et al. (1967). Because the value of radial hydraulic conductivity is obtained from a match point, the number of unknowns is reduced to three. The estimated values of radial hydraulic conductivity and specific storage are comparable to those derived from the methods of Bouwer and Rice (1976) and Cooper et al. (1967). The values and skin conductivity, however, could not have been obtained without the use of observation wells.Normally, slug test measurements are limited to the well in which the water level is perturbed. Consequently, it is often difficult to obtain reliable estimates of hydraulic properties, particularly if the aquifer is anisotropic or if there is a wellbore skin. In this investigation, we use partially penetrating stress and observation wells to evaluate specific storage, radial hydraulic conductivity and anisotropy of the aquifer, and the hydraulic conductivity of the borehole skin. The study site is located in the W9 subbasin of the Sleepers River Research Watershed, Vermont. At the site, approximately 3 m of saturated till are partially penetrated by a stress well located in the center of the unconfined aquifer and six observation wells located above, below, and at the depth of the stress well at radial distances of 1.2 and 2.4 m. The observation wells were shut in with inflatable packers. The semianalytical solution of Buffer (1995) was used to conduct a sensitivity analysis and to interpret slug test results. The sensitivity analysis indicates that the response of the stress well is primarily sensitive to radial hydraulic conductivity, less sensitive to anisotropy and the conductivity of the borehole skin, and nearly insensitive to specific storage. In contrast, the responses of the observation wells are sensitive to all four parameters. Interpretation of the field data was facilitated by generating type curves in a manner analogous to the method of Cooper et al. (1967). Because the value of radial hydraulic conductivity is obtained from a match point, the number of unknowns is reduced to three. The estimated values of radial hydraulic conductivity and specific storage are comparable to those derived from the methods of Bouwer and Rice (1976) and Cooper et al. (1967). The values and skin conductivity, however, could not have been obtained without the use of observation wells.

Comparative Genomic Analysis of Haemophilus haemolyticus and Nontypeable Haemophilus influenzae and a New Testing Scheme for Their Discrimination.

PubMed

Hu, Fang; Rishishwar, Lavanya; Sivadas, Ambily; Mitchell, Gabriel J; Jordan, I King; Murphy, Timothy F; Gilsdorf, Janet R; Mayer, Leonard W; Wang, Xin

2016-12-01

Haemophilus haemolyticus has been recently discovered to have the potential to cause invasive disease. It is closely related to nontypeable Haemophilus influenzae (NT H. influenzae). NT H. influenzae and H. haemolyticus are often misidentified because none of the existing tests targeting the known phenotypes of H. haemolyticus are able to specifically identify H. haemolyticus Through comparative genomic analysis of H. haemolyticus and NT H. influenzae, we identified genes unique to H. haemolyticus that can be used as targets for the identification of H. haemolyticus A real-time PCR targeting purT (encoding phosphoribosylglycinamide formyltransferase 2 in the purine synthesis pathway) was developed and evaluated. The lower limit of detection was 40 genomes/PCR; the sensitivity and specificity in detecting H. haemolyticus were 98.9% and 97%, respectively. To improve the discrimination of H. haemolyticus and NT H. influenzae, a testing scheme combining two targets (H. haemolyticus purT and H. influenzae hpd, encoding protein D lipoprotein) was also evaluated and showed 96.7% sensitivity and 98.2% specificity for the identification of H. haemolyticus and 92.8% sensitivity and 100% specificity for the identification of H. influenzae, respectively. The dual-target testing scheme can be used for the diagnosis and surveillance of infection and disease caused by H. haemolyticus and NT H. influenzae. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Comparison of DWI and PET/CT in evaluation of lymph node metastasis in uterine cancer

PubMed Central

Kitajima, Kazuhiro; Yamasaki, Erena; Kaji, Yasushi; Murakami, Koji; Sugimura, Kazuro

2012-01-01

AIM: To investigate diffusion-weighted imaging (DWI) and positron emission tomography and computed tomography (PET/CT) with IV contrast for the preoperative evaluation of pelvic lymph node (LN) metastasis in uterine cancer. METHODS: Twenty-five patients with endometrial or cervical cancer who underwent both DWI and PET/CT before pelvic lymphadenectomy were included in this study. For area specific analysis, LNs were divided into eight regions: both common iliac, external iliac, internal iliac areas, and obturator areas. The classification for malignancy on DWI was a focally abnormal signal intensity in a location that corresponded to the LN chains on the T1WI and T2WI. The criterion for malignancy on PET/CT images was increased tracer uptake by the LN. RESULTS: A total of 36 pathologically positive LN areas were found in 9 patients. With DWI, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy for detecting metastatic LNs on an LN area-by-area analysis were 83.3%, 51.2%, 27.3%, 93.3% and 57.0%, respectively, while the corresponding values for PET/CT were 38.9%, 96.3%, 70.0%, 87.8% and 86.0%. Differences in sensitivity, specificity and accuracy were significant (P < 0.0005). CONCLUSION: DWI showed higher sensitivity and lower specificity than PET/CT. Neither DWI nor PET/CT were sufficiently accurate to replace lymphadenectomy. PMID:22761980

Comparative Genomic Analysis of Haemophilus haemolyticus and Nontypeable Haemophilus influenzae and a New Testing Scheme for Their Discrimination

PubMed Central

Hu, Fang; Rishishwar, Lavanya; Sivadas, Ambily; Mitchell, Gabriel J.; Jordan, I. King; Murphy, Timothy F.; Gilsdorf, Janet R.; Mayer, Leonard W.

2016-01-01

Haemophilus haemolyticus has been recently discovered to have the potential to cause invasive disease. It is closely related to nontypeable Haemophilus influenzae (NT H. influenzae). NT H. influenzae and H. haemolyticus are often misidentified because none of the existing tests targeting the known phenotypes of H. haemolyticus are able to specifically identify H. haemolyticus. Through comparative genomic analysis of H. haemolyticus and NT H. influenzae, we identified genes unique to H. haemolyticus that can be used as targets for the identification of H. haemolyticus. A real-time PCR targeting purT (encoding phosphoribosylglycinamide formyltransferase 2 in the purine synthesis pathway) was developed and evaluated. The lower limit of detection was 40 genomes/PCR; the sensitivity and specificity in detecting H. haemolyticus were 98.9% and 97%, respectively. To improve the discrimination of H. haemolyticus and NT H. influenzae, a testing scheme combining two targets (H. haemolyticus purT and H. influenzae hpd, encoding protein D lipoprotein) was also evaluated and showed 96.7% sensitivity and 98.2% specificity for the identification of H. haemolyticus and 92.8% sensitivity and 100% specificity for the identification of H. influenzae, respectively. The dual-target testing scheme can be used for the diagnosis and surveillance of infection and disease caused by H. haemolyticus and NT H. influenzae. PMID:27707939

Evaluation of erythrocyte dysmorphism by light microscopy with lowering of the condenser lens: A simple and efficient method.

PubMed

Barros Silva, Gyl Eanes; Costa, Roberto Silva; Ravinal, Roberto Cuan; Saraiva e Silva, Jucélia; Dantas, Marcio; Coimbra, Terezila Machado

2010-03-01

To demonstrate that the evaluation of erythrocyte dysmorphism by light microscopy with lowering of the condenser lens (LMLC) is useful to identify patients with a haematuria of glomerular or non-glomerular origin. A comparative double-blind study between phase contrast microscopy (PCM) and LMLC is reported to evaluate the efficacy of these techniques. Urine samples of 39 patients followed up for 9 months were analyzed, and classified as glomerular and non-glomerular haematuria. The different microscopic techniques were compared using receiver-operator curve (ROC) analysis and area under curve (AUC). Reproducibility was assessed by coefficient of variation (CV). Specific cut-offs were set for each method according to their best rate of specificity and sensitivity as follows: 30% for phase contrast microscopy and 40% for standard LMLC, reaching in the first method the rate of 95% and 100% of sensitivity and specificity, respectively, and in the second method the rate of 90% and 100% of sensitivity and specificity, respectively. In ROC analysis, AUC for PCM was 0.99 and AUC for LMLC was 0.96. The CV was very similar in glomerular haematuria group for PCM (35%) and LMLC (35.3%). LMLC proved to be effective in contributing to the direction of investigation of haematuria, toward the nephrological or urological side. This method can substitute PCM when this equipment is not available.

Improving guideline sensitivity and specificity for the identification of proactive gastrostomy placement in patients with head and neck cancer.

PubMed

Brown, Teresa E; Crombie, Jane; Spurgin, Ann-Louise; Tripcony, Lee; Keller, Jacqui; Hughes, Brett G M; Dickie, Graeme; Kenny, Lizbeth Moira; Hodge, Robert A

2016-04-01

Swallowing and nutrition guidelines for patients with head and neck cancer are available for identification of proactive gastrostomy placement in patients with high nutritional risk. The purpose of this study was to investigate improvements to the validity of these guidelines. A multivariate analysis was fitted to the original dataset (n = 501) to examine the variables that may predict gastrostomy placement (eg, tumor site, treatment, sex, and age). Using these factors, the high risk category was modified and retrospectively validated in the same cohort to provide new measures of sensitivity and specificity. The following were positive predictors of gastrostomy placement: T3 (p = .01), T4 (p < .001), and chemoradiotherapy (p < .001). Laryngeal (p = .02) and skin cancer (p < .001) were negative predictors. Modification of the high risk definition improved sensitivity to 58% and maintained specificity at 92%. Minor modifications to the high risk definition in the guidelines have improved the guideline sensitivity for future use. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1163-E1171, 2016. © 2015 Wiley Periodicals, Inc.

Diagnostic Value of Cerebrospinal Fluid T-SPOT.TB for Tuberculousis Meningitis in China.

PubMed

Li, Xue Lian; Xie, Na; Wang, Song Wang; Wu, Qian Hong; Ma, Yan; Shu, Wei; Chen, Hong Mei; Zhang, Li Qun; Wu, Xiao Guang; Ma, Li Ping; Che, Nan Ying; Gao, Meng Qiu

2017-09-01

The aim of this study was to evaluate the diagnostic value of the cerebrospinal fluid (CSF) T-SPOT.TB test for the diagnosis of TB meningitis (TBM). A retrospective analysis of 96 patients with manifested meningitis was conducted; T-SPOT.TB test was performed for diagnosing TBM to determine the diagnostic sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). A receiver operating characteristic (ROC) curve was also drawn to assess the diagnostic accuracy. The sensitivity, specificity, PPV, and NPV of CSF T-SPOT.TB test were 97.8%, 78.0%, 80.3%, and 97.5%, respectively, for 52 patients (54.2%) of the 96 enrolled patients. The area under the curve (AUC) was 0.910, and the sensitivities of CSF T-SPOT.TB for patients with stages I, II, and III of TBM were 96.7%, 97.2%, and 98.9%, respectively. CSF T-SPOT.TB test is a rapid and accurate diagnostic method with higher sensitivity and specificity for diagnosing TBM. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Antibody against mutated citrullinated vimentin: a new sensitive marker in the diagnosis of rheumatoid arthritis.

PubMed

Wagner, Ernst; Skoumal, M; Bayer, P M; Klaushofer, K

2009-09-01

The aim of this study was to determine the performance of antibodies against mutated citrullinated vimentin (anti-MCV) in comparison with antibodies to cyclic citrullinated peptides (anti-CCP) in patients with rheumatoid arthritis (RA). Serum levels of anti-MCV and anti-CCP were determined in 193 patients with RA and 332 controls, and sensitivity and specificity were calculated. In a separate analysis of 86 patients, the anti-MCV levels were compared to disease activity. Sensitivity of anti-MCV versus anti-CCP was 71.5 and 69.4%, specificity was 81.3 and 97.6%, respectively. The ROC curves showed higher specificity and an advantage of anti-CCP. In seronegative RA patients the sensitivity of anti-MCV was superior over anti-CCP. Anti-MCV positivities also occurred in systemic lupus erythematosus and Sjoegren's syndrome. In a subgroup of 86 RA patients we found a significant correlation between anti-MCV and disease activity. Anti-MCV appears to be an important marker for the diagnosis of RA, and correlates also with disease activity.

Computed Tomography-Derived Fractional Flow Reserve in the Detection of Lesion-Specific Ischemia: An Integrated Analysis of 3 Pivotal Trials.

PubMed

Xu, Rende; Li, Chenguang; Qian, Juying; Ge, Junbo

2015-11-01

Invasive fractional flow reserve (FFR) is the gold standard for the determination of physiologic stenosis severity and the need for revascularization. FFR computed from standard acquired coronary computed tomographic angiography datasets (FFRCT) is an emerging technology which allows calculation of FFR using resting image data from coronary computed tomographic angiography (CCTA). However, the diagnostic accuracy of FFRCT in the evaluation of lesion-specific myocardial ischemia remains to be confirmed, especially in patients with intermediate coronary stenosis. We performed an integrated analysis of data from 3 prospective, international, and multicenter trials, which assessed the diagnostic performance of FFRCT using invasive FFR as a reference standard. Three studies evaluating 609 patients and 1050 vessels were included. The total calculated sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of FFRCT were 82.8%, 77.7%, 60.8%, 91.6%, and 79.2%, respectively, for the per-vessel analysis, and 89.4%, 70.5%, 69.7%, 89.7%, and 78.7%, respectively, for the per-patient analysis. Compared with CCTA alone, FFRCT demonstrated significantly improved accuracy (P < 0.001) in detecting lesion-specific ischemia. In patients with intermediate coronary stenosis, FFRCT remained both highly sensitive and specific with respect to the diagnosis of ischemia. In conclusion, FFRCT appears to be a reliable noninvasive alternative to invasive FFR, as it demonstrates high accuracy in the determination of anatomy and lesion-specific ischemia, which justifies the performance of additional randomized controlled trials to evaluate both the clinical benefits and the cost-effectiveness of FFRCT-guided coronary revascularization.

Sensitivity and Specificity of Biochemical Tests for Diagnosis of Intrahepatic Cholestasis of Pregnancy.

PubMed

Jurate, Kondrackiene; Rimantas, Zalinkevicius; Jolanta, Sumskiene; Vladas, Gintautas; Limas, Kupcinskas

2017-01-01

Intrahepatic cholestasis of pregnancy (ICP) is linked with increased risk of fetal complications. An accurate diagnostic test is needed to diagnose this disorder on time. We aimed to assess sensitivity and specificity of laboratory tests used for diagnosis of intrahepatic cholestasis of pregnancy and determine more reliable cut-off values of transaminases. Sixty one symptomatic patients with ICP and 29 healthy pregnant women were included in the retrospective analysis. ICP patients had higher total bile acids (TBA) levels than healthy women (32 vs. 6; P < 0.0001) due to increase in cholic acid (CA) and chenodeoxycholic acid (CDCA). CA/CDCA ratio was significantly higher in ICP patients compared to healthy pregnant women (1.13 vs. 0.68; P < 0.00002). TBA, CA, CDCA and CA/CDCA ratio demonstrate the following sensitivity (94%, 96%, 89%, 71.9%) and specificity (63%, 63%, 59%, 79.3%, respectively) for ICP diagnosis. Lowering cut-off values for ALT (31 U/L) and AST (30 U/L) resulted only in minimal increase of sensitivity to 92.2% vs. 90.1% for ALT and to 92.2%, vs. 90.6% for AST. The present study did not reveal any single specific and sensitive marker for reliable diagnosis of ICP. Establishment of lower cut-off values for transaminases activity might only minimally increase the accuracy of diagnosing ICP.

Is High Resolution Melting Analysis (HRMA) Accurate for Detection of Human Disease-Associated Mutations? A Meta Analysis

PubMed Central

Ma, Feng-Li; Jiang, Bo; Song, Xiao-Xiao; Xu, An-Gao

2011-01-01

Background High Resolution Melting Analysis (HRMA) is becoming the preferred method for mutation detection. However, its accuracy in the individual clinical diagnostic setting is variable. To assess the diagnostic accuracy of HRMA for human mutations in comparison to DNA sequencing in different routine clinical settings, we have conducted a meta-analysis of published reports. Methodology/Principal Findings Out of 195 publications obtained from the initial search criteria, thirty-four studies assessing the accuracy of HRMA were included in the meta-analysis. We found that HRMA was a highly sensitive test for detecting disease-associated mutations in humans. Overall, the summary sensitivity was 97.5% (95% confidence interval (CI): 96.8–98.5; I2 = 27.0%). Subgroup analysis showed even higher sensitivity for non-HR-1 instruments (sensitivity 98.7% (95%CI: 97.7–99.3; I2 = 0.0%)) and an eligible sample size subgroup (sensitivity 99.3% (95%CI: 98.1–99.8; I2 = 0.0%)). HRMA specificity showed considerable heterogeneity between studies. Sensitivity of the techniques was influenced by sample size and instrument type but by not sample source or dye type. Conclusions/Significance These findings show that HRMA is a highly sensitive, simple and low-cost test to detect human disease-associated mutations, especially for samples with mutations of low incidence. The burden on DNA sequencing could be significantly reduced by the implementation of HRMA, but it should be recognized that its sensitivity varies according to the number of samples with/without mutations, and positive results require DNA sequencing for confirmation. PMID:22194806

Pain sensitivity profiles in patients with advanced knee osteoarthritis

PubMed Central

Frey-Law, Laura A.; Bohr, Nicole L.; Sluka, Kathleen A.; Herr, Keela; Clark, Charles R.; Noiseux, Nicolas O.; Callaghan, John J; Zimmerman, M Bridget; Rakel, Barbara A.

2016-01-01

The development of patient profiles to subgroup individuals on a variety of variables has gained attention as a potential means to better inform clinical decision-making. Patterns of pain sensitivity response specific to quantitative sensory testing (QST) modality have been demonstrated in healthy subjects. It has not been determined if these patterns persist in a knee osteoarthritis population. In a sample of 218 participants, 19 QST measures along with pain, psychological factors, self-reported function, and quality of life were assessed prior to total knee arthroplasty. Component analysis was used to identify commonalities across the 19 QST assessments to produce standardized pain sensitivity factors. Cluster analysis then grouped individuals that exhibited similar patterns of standardized pain sensitivity component scores. The QST resulted in four pain sensitivity components: heat, punctate, temporal summation, and pressure. Cluster analysis resulted in five pain sensitivity profiles: a “low pressure pain” group, an “average pain” group, and three “high pain” sensitivity groups who were sensitive to different modalities (punctate, heat, and temporal summation). Pain and function differed between pain sensitivity profiles, along with sex distribution; however no differences in OA grade, medication use, or psychological traits were found. Residualizing QST data by age and sex resulted in similar components and pain sensitivity profiles. Further, these profiles are surprisingly similar to those reported in healthy populations suggesting that individual differences in pain sensitivity are a robust finding even in an older population with significant disease. PMID:27152688

PAX1 and SOX1 methylation as an initial screening method for cervical cancer: a meta-analysis of individual studies in Asians

PubMed Central

Cui, Zhaolei; Xiao, Zhenzhou; Hu, Minhua; Jiang, Chuanhui; Lin, Yingying; Chen, Yansong

2016-01-01

Background Epigenetic alterations of gene or DNA methylation have been highlighted as promising biomarkers for early cervical cancer screening. Herein, we evaluated the diagnostic performance of paired boxed gene 1 (PAX1) and sex determining region Y-box 1 (SOX1) methylation for cervical cancer detection. Methods Eligible studies were retrieved by searching the electronic databases. Study quality was assessed according to the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) checklist. The bivariate meta-analysis model was employed to plot the summary receiver operator characteristic (SROC) curve using Stata 12.0 software. Results The pooled sensitivity of PAX1 methylation was estimated to be 0.73 [95% confidence interval (CI): 0.70–0.75] in differentiating patients with HSIL (high-grade squamous intraepithelial lesion) or CIN3+ (cervical intraepithelial neoplasia type III/worse) or cervical cancer from normal individuals, corresponding to a specificity of 0.87 (95% CI: 0.85–0.89) and area under the curve (AUC) of 0.91. The SOX1 methylation test yielded an AUC of 0.82, under which, the pooled sensitivity was 0.71 (95% CI: 0.67–0.74) and specificity was 0.64 (95% CI: 0.61–0.67). Notably, the stratified analysis suggested that combing parallel testing of PAX1 methylation and human papillomavirus (HPV) DNA (AUC, sensitivity, and specificity of 0.89, 0.75, and 0.81, respectively) achieved higher accuracy than single HPV DNA testing (AUC, sensitivity, and specificity of 0.77, 0.81, and 0.70, respectively). Conclusions PAX1 or SOX1 methylation has a prospect to be an auxiliary biomarker for cervical cancer screening, and parallel testing of PAX1 methylation and HPV DNA in cervical swabs confers an improved diagnostic accuracy than single HPV DNA testing. PMID:27826568

Standard echocardiography versus handheld echocardiography for the detection of subclinical rheumatic heart disease: protocol for a systematic review

PubMed Central

Telford, Lisa H; Abdullahi, Leila H; Ochodo, Eleanor A; Engel, Mark E

2018-01-01

Introduction Rheumatic heart disease (RHD) is a preventable and treatable chronic condition which persists in many developing countries largely affecting impoverished populations. Handheld echocardiography presents an opportunity to address the need for more cost-effective methods of diagnosing RHD in developing countries, where the disease continues to carry high rates of morbidity and mortality. Preliminary studies have demonstrated moderate sensitivity as well as high specificity and diagnostic odds for detecting RHD in asymptomatic patients. We describe a protocol for a systematic review on the diagnostic performance of handheld echocardiography compared to standard echocardiography using the 2012 World Heart Federation criteria for diagnosing subclinical RHD. Methods and analysis Electronic databases including PubMed, Scopus, Web of Science and EBSCOhost as well as reference lists and citations of relevant articles will be searched from 2012 to date using a predefined strategy incorporating a combination of Medical Subject Heading terms and keywords. The methodological validity and quality of studies deemed eligible for inclusion will be assessed against review specific Quality Assessment of Diagnostic Accuracy Studies 2 criteria and information on metrics of diagnostic accuracy and demographics extracted. Forest plots of sensitivity and specificity as well as scatter plots in receiver operating characteristic (ROC) space will be used to investigate heterogeneity. If possible, a meta-analysis will be conducted to produce summary results of sensitivity and specificity using the Hierarchical Summary ROC method. In addition, a sensitivity analysis will be conducted to investigate the effect of studies with a high risk of bias. Ethics and dissemination Ethics approval is not required for this systematic review of previously published literature. The planned review will provide a summary of the diagnostic accuracy of handheld echocardiography. Results may feed into evidence-based guidelines and should the findings of this review warrant a change in clinical practice, a summary report will be disseminated among leading clinicians and healthcare professionals in the field. PROSPERO registration number CRD42016051261. PMID:29440164

Sensitivity and specificity of eustachian tube function tests in adults.

PubMed

Doyle, William J; Swarts, J Douglas; Banks, Julianne; Casselbrant, Margaretha L; Mandel, Ellen M; Alper, Cuneyt M

2013-07-01

The study demonstrates the utility of eustachian tube (ET) function (ETF) test results for accurately assigning ears to disease state. To determine if ETF tests can identify ears with physician-diagnosed ET dysfunction (ETD) in a mixed population at high sensitivity and specificity and to define the interrelatedness of ETF test parameters. Through use of the forced-response, inflation-deflation, Valsalva, and sniffing tests, ETF was evaluated in 15 control ears of adult subjects after unilateral myringotomy (group 1) and in 23 ears of 19 adult subjects with ventilation tubes inserted for ETD (group 2). Data were analyzed using logistic regression including each parameter independently and then a step-down discriminant analysis including all ETF test parameters to predict group assignment. Factor analysis operating over all parameters was used to explore relatedness. ETF testing. ETF parameters for the forced response, inflation-deflation, Valsalva, and sniffing tests measured in 15 control ears of adult subjects after unilateral myringotomy (group 1) and in 23 ears of 19 adult subjects with ventilation tubes inserted for ETD (group 2). The discriminant analysis identified 4 ETF test parameters (Valsalva, ET opening pressure, dilatory efficiency, and percentage of positive pressure equilibrated) that together correctly assigned ears to group 2 at a sensitivity of 95% and a specificity of 83%. Individual parameters representing the efficiency of ET opening during swallowing showed moderately accurate assignments of ears to their respective groups. Three factors captured approximately 98% of the variance among parameters: the first had negative loadings of the ETF structural parameters; the second had positive loadings of the muscle-assisted ET opening parameters; and the third had negative loadings of the muscle-assisted ET opening parameters and positive loadings of the structural parameters. These results show that ETF tests can correctly assign individual ears to physician-diagnosed ETD with high sensitivity and specificity and that ETF test parameters can be grouped into structural-functional categories.

Prospective evaluation of free-breathing diffusion-weighted imaging for the detection of inflammatory bowel disease with MR enterography in childhood population

PubMed Central

Dubron, Céline; Avni, Freddy; Boutry, Nathalie; Turck, Dominique; Duhamel, Alain

2016-01-01

Objective: To evaluate prospectively the performance of diffusion-weighted imaging (DWI) for the detection of active lesions on MR enterography (MRE) in children with inflammatory bowel disease (IBD). Methods: MRE of 48 children (mean age 13 years) with suspected or known IBD were blindly analysed by 2 independent readers for the presence of active lesions. Two sets of imaging including DWI and gadolinium-enhanced imaging (GEI) were reviewed. A reader consensus was obtained. The gold standard was histopathological findings. In patient-level analysis and segment-level analysis, sensitivity and specificity were calculated for DWI and GEI and compared using McNemar's test or logistic random-effects models. Results: At least 1 active lesion was confirmed in 42 (87.5%) children. Sensitivity and specificity for the detection of at least one lesion were 88.1% (95% CI, 74.3–96.1) and 83.3% (95% CI, 35.9–99.6), respectively, for DWI and 66.7% (95% CI, 50.4–80.4) and 83.3% (95% CI, 35.9–99.6), respectively, for GEI. In segment-level analysis, sensitivity and specificity for the detection of specific segment lesions were 62.5% (95% CI, 48.1–75) and 97.1% (95% CI, 93.5–98.7), respectively, for DWI and 45.7% (95% CI, 30.8–61.3) and 98.2% (95% CI, 95.3–99.4), respectively, for GEI. The sensitivity of DWI was significantly better than that of GEI per patient (p = 0.004) and per segment (p = 0.028). Conclusion: DWI demonstrates better performance than GEI for the detection of active lesions in children with IBD. Advances in knowledge: Examination with no intravenous injection–DWI can replace T1 weighted images when paediatric patients are screened with MRE for IBD. Examination performed in free breathing is better tolerated by children. PMID:26838954

Prospective evaluation of free-breathing diffusion-weighted imaging for the detection of inflammatory bowel disease with MR enterography in childhood population.

PubMed

Dubron, Céline; Avni, Freddy; Boutry, Nathalie; Turck, Dominique; Duhamel, Alain; Amzallag-Bellenger, Elisa

2016-01-01

To evaluate prospectively the performance of diffusion-weighted imaging (DWI) for the detection of active lesions on MR enterography (MRE) in children with inflammatory bowel disease (IBD). MRE of 48 children (mean age 13 years) with suspected or known IBD were blindly analysed by 2 independent readers for the presence of active lesions. Two sets of imaging including DWI and gadolinium-enhanced imaging (GEI) were reviewed. A reader consensus was obtained. The gold standard was histopathological findings. In patient-level analysis and segment-level analysis, sensitivity and specificity were calculated for DWI and GEI and compared using McNemar's test or logistic random-effects models. At least 1 active lesion was confirmed in 42 (87.5%) children. Sensitivity and specificity for the detection of at least one lesion were 88.1% (95% CI, 74.3-96.1) and 83.3% (95% CI, 35.9-99.6), respectively, for DWI and 66.7% (95% CI, 50.4-80.4) and 83.3% (95% CI, 35.9-99.6), respectively, for GEI. In segment-level analysis, sensitivity and specificity for the detection of specific segment lesions were 62.5% (95% CI, 48.1-75) and 97.1% (95% CI, 93.5-98.7), respectively, for DWI and 45.7% (95% CI, 30.8-61.3) and 98.2% (95% CI, 95.3-99.4), respectively, for GEI. The sensitivity of DWI was significantly better than that of GEI per patient (p = 0.004) and per segment (p = 0.028). DWI demonstrates better performance than GEI for the detection of active lesions in children with IBD. Examination with no intravenous injection-DWI can replace T1 weighted images when paediatric patients are screened with MRE for IBD. Examination performed in free breathing is better tolerated by children.

Predicting Fluid Responsiveness by Passive Leg Raising: A Systematic Review and Meta-Analysis of 23 Clinical Trials.

PubMed

Cherpanath, Thomas G V; Hirsch, Alexander; Geerts, Bart F; Lagrand, Wim K; Leeflang, Mariska M; Schultz, Marcus J; Groeneveld, A B Johan

2016-05-01

Passive leg raising creates a reversible increase in venous return allowing for the prediction of fluid responsiveness. However, the amount of venous return may vary in various clinical settings potentially affecting the diagnostic performance of passive leg raising. Therefore we performed a systematic meta-analysis determining the diagnostic performance of passive leg raising in different clinical settings with exploration of patient characteristics, measurement techniques, and outcome variables. PubMed, EMBASE, the Cochrane Database of Systematic Reviews, and citation tracking of relevant articles. Clinical trials were selected when passive leg raising was performed in combination with a fluid challenge as gold standard to define fluid responders and non-responders. Trials were included if data were reported allowing the extraction of sensitivity, specificity, and area under the receiver operating characteristic curve. Twenty-three studies with a total of 1,013 patients and 1,034 fluid challenges were included. The analysis demonstrated a pooled sensitivity of 86% (95% CI, 79-92), pooled specificity of 92% (95% CI, 88-96), and a summary area under the receiver operating characteristic curve of 0.95 (95% CI, 0.92-0.98). Mode of ventilation, type of fluid used, passive leg raising starting position, and measurement technique did not affect the diagnostic performance of passive leg raising. The use of changes in pulse pressure on passive leg raising showed a lower diagnostic performance when compared with passive leg raising-induced changes in flow variables, such as cardiac output or its direct derivatives (sensitivity of 58% [95% CI, 44-70] and specificity of 83% [95% CI, 68-92] vs sensitivity of 85% [95% CI, 78-90] and specificity of 92% [95% CI, 87-94], respectively; p < 0.001). Passive leg raising retains a high diagnostic performance in various clinical settings and patient groups. The predictive value of a change in pulse pressure on passive leg raising is inferior to a passive leg raising-induced change in a flow variable.

The Diagnostic Value of Capillary Refill Time for Detecting Serious Illness in Children: A Systematic Review and Meta-Analysis

PubMed Central

Fleming, Susannah; Gill, Peter; Jones, Caroline; Taylor, James A.; Van den Bruel, Ann; Heneghan, Carl; Roberts, Nia; Thompson, Matthew

2015-01-01

Importance Capillary refill time (CRT) is widely recommended as part of the routine assessment of unwell children. Objective To determine the diagnostic value of capillary refill time for a range of serious outcomes in children. Methods We searched Medline, Embase and CINAHL from inception to June 2014. We included studies that measured both capillary refill time and a relevant clinical outcome such as mortality, dehydration, meningitis, or other serious illnesses in children aged up to 18 years of age. We screened 1,265 references, of which 24 papers were included in this review. Where sufficient studies were available, we conducted meta-analysis and constructed hierarchical summary ROC curves. Results Meta-analysis on the relationship between capillary refill time and mortality resulted in sensitivity of 34.6% (95% CI 23.9 to 47.1%), specificity 92.3% (88.6 to 94.8%), positive likelihood ratio 4.49 (3.06 to 6.57), and negative likelihood ratio 0.71 (0.60 to 0.84). Studies of children attending Emergency Departments with vomiting and diarrhea showed that capillary refill time had specificity of 89 to 94% for identifying 5% dehydration, but sensitivity ranged from 0 to 94%. This level of heterogeneity precluded formal meta-analysis of this outcome. Meta-analysis was not possible for other outcomes due to insufficient data, but we found consistently high specificity for a range of outcomes including meningitis, sepsis, admission to hospital, hypoxia, severity of illness and dengue. Conclusions Our results show that capillary refill time is a specific sign, indicating that it can be used as a “red-flag”: children with prolonged capillary refill time have a four-fold risk of dying compared to children with normal capillary refill time. The low sensitivity means that a normal capillary refill time should not reassure clinicians. PMID:26375953

Immunotoxicological Analysis of the Immune Adjuvant Effects of Source Specific Diesel and Environmental Ambient Particulate Matter in a Murine Sensitization And Challenge Model.

EPA Science Inventory

Rationale: Acute exposure to ambient particulate matter (APM) provokes oxidative and inflammatory lung activation in vivo. Here, we test the hypothesis that environmental diesel exhaust particles (eDEP), emission source-specific DEP (cDEP) and APM differentially provoke an allerg...

Development and application of a PCR assay to detect chicken and turkey parvoviruses in commercial poultry flocks in the United States.

USDA-ARS?s Scientific Manuscript database

Comparative sequence analysis of six independent chicken and turkey parvovirus nonstructural (NS) genes revealed specific genomic regions with 100% nucleotide sequence identity. A PCR assay with primers targeting these conserved genome sequences proved to be highly specific and sensitive to detect p...

Clinical evaluation and validation of laboratory methods for the diagnosis of Bordetella pertussis infection: Culture, polymerase chain reaction (PCR) and anti-pertussis toxin IgG serology (IgG-PT).

PubMed

Lee, Adria D; Cassiday, Pamela K; Pawloski, Lucia C; Tatti, Kathleen M; Martin, Monte D; Briere, Elizabeth C; Tondella, M Lucia; Martin, Stacey W

2018-01-01

The appropriate use of clinically accurate diagnostic tests is essential for the detection of pertussis, a poorly controlled vaccine-preventable disease. The purpose of this study was to estimate the sensitivity and specificity of different diagnostic criteria including culture, multi-target polymerase chain reaction (PCR), anti-pertussis toxin IgG (IgG-PT) serology, and the use of a clinical case definition. An additional objective was to describe the optimal timing of specimen collection for the various tests. Clinical specimens were collected from patients with cough illness at seven locations across the United States between 2007 and 2011. Nasopharyngeal and blood specimens were collected from each patient during the enrollment visit. Patients who had been coughing for ≤ 2 weeks were asked to return in 2-4 weeks for collection of a second, convalescent blood specimen. Sensitivity and specificity of each diagnostic test were estimated using three methods-pertussis culture as the "gold standard," composite reference standard analysis (CRS), and latent class analysis (LCA). Overall, 868 patients were enrolled and 13.6% were B. pertussis positive by at least one diagnostic test. In a sample of 545 participants with non-missing data on all four diagnostic criteria, culture was 64.0% sensitive, PCR was 90.6% sensitive, and both were 100% specific by LCA. CRS and LCA methods increased the sensitivity estimates for convalescent serology and the clinical case definition over the culture-based estimates. Culture and PCR were most sensitive when performed during the first two weeks of cough; serology was optimally sensitive after the second week of cough. Timing of specimen collection in relation to onset of illness should be considered when ordering diagnostic tests for pertussis. Consideration should be given to including IgG-PT serology as a confirmatory test in the Council of State and Territorial Epidemiologists (CSTE) case definition for pertussis.

Critical comparison of diffuse reflectance spectroscopy and colorimetry as dermatological diagnostic tools for acanthosis nigricans: a chemometric approach

PubMed Central

Devpura, Suneetha; Pattamadilok, Bensachee; Syed, Zain U.; Vemulapalli, Pranita; Henderson, Marsha; Rehse, Steven J.; Hamzavi, Iltefat; Lim, Henry W.; Naik, Ratna

2011-01-01

Quantification of skin changes due to acanthosis nigricans (AN), a disorder common among insulin-resistant diabetic and obese individuals, was investigated using two optical techniques: diffuse reflectance spectroscopy (DRS) and colorimetry. Measurements were obtained from AN lesions on the neck and two control sites of eight AN patients. A principal component/discriminant function analysis successfully differentiated between AN lesion and normal skin with 87.7% sensitivity and 94.8% specificity in DRS measurements and 97.2% sensitivity and 96.4% specificity in colorimetry measurements. PMID:21698027

Wavelet analysis enables system-independent texture analysis of optical coherence tomography images.

PubMed

Lingley-Papadopoulos, Colleen A; Loew, Murray H; Zara, Jason M

2009-01-01

Texture analysis for tissue characterization is a current area of optical coherence tomography (OCT) research. We discuss some of the differences between OCT systems and the effects those differences have on the resulting images and subsequent image analysis. In addition, as an example, two algorithms for the automatic recognition of bladder cancer are compared: one that was developed on a single system with no consideration for system differences, and one that was developed to address the issues associated with system differences. The first algorithm had a sensitivity of 73% and specificity of 69% when tested using leave-one-out cross-validation on data taken from a single system. When tested on images from another system with a different central wavelength, however, the method classified all images as cancerous regardless of the true pathology. By contrast, with the use of wavelet analysis and the removal of system-dependent features, the second algorithm reported sensitivity and specificity values of 87 and 58%, respectively, when trained on images taken with one imaging system and tested on images taken with another.

Wavelet analysis enables system-independent texture analysis of optical coherence tomography images

NASA Astrophysics Data System (ADS)

Lingley-Papadopoulos, Colleen A.; Loew, Murray H.; Zara, Jason M.

2009-07-01

Texture analysis for tissue characterization is a current area of optical coherence tomography (OCT) research. We discuss some of the differences between OCT systems and the effects those differences have on the resulting images and subsequent image analysis. In addition, as an example, two algorithms for the automatic recognition of bladder cancer are compared: one that was developed on a single system with no consideration for system differences, and one that was developed to address the issues associated with system differences. The first algorithm had a sensitivity of 73% and specificity of 69% when tested using leave-one-out cross-validation on data taken from a single system. When tested on images from another system with a different central wavelength, however, the method classified all images as cancerous regardless of the true pathology. By contrast, with the use of wavelet analysis and the removal of system-dependent features, the second algorithm reported sensitivity and specificity values of 87 and 58%, respectively, when trained on images taken with one imaging system and tested on images taken with another.

Probabilistic Sensitivity Analysis for Launch Vehicles with Varying Payloads and Adapters for Structural Dynamics and Loads

NASA Technical Reports Server (NTRS)

McGhee, David S.; Peck, Jeff A.; McDonald, Emmett J.

2012-01-01

This paper examines Probabilistic Sensitivity Analysis (PSA) methods and tools in an effort to understand their utility in vehicle loads and dynamic analysis. Specifically, this study addresses how these methods may be used to establish limits on payload mass and cg location and requirements on adaptor stiffnesses while maintaining vehicle loads and frequencies within established bounds. To this end, PSA methods and tools are applied to a realistic, but manageable, integrated launch vehicle analysis where payload and payload adaptor parameters are modeled as random variables. This analysis is used to study both Regional Response PSA (RRPSA) and Global Response PSA (GRPSA) methods, with a primary focus on sampling based techniques. For contrast, some MPP based approaches are also examined.

Automatic classification of small bowel mucosa alterations in celiac disease for confocal laser endomicroscopy

NASA Astrophysics Data System (ADS)

Boschetto, Davide; Di Claudio, Gianluca; Mirzaei, Hadis; Leong, Rupert; Grisan, Enrico

2016-03-01

Celiac disease (CD) is an immune-mediated enteropathy triggered by exposure to gluten and similar proteins, affecting genetically susceptible persons, increasing their risk of different complications. Small bowels mucosa damage due to CD involves various degrees of endoscopically relevant lesions, which are not easily recognized: their overall sensitivity and positive predictive values are poor even when zoom-endoscopy is used. Confocal Laser Endomicroscopy (CLE) allows skilled and trained experts to qualitative evaluate mucosa alteration such as a decrease in goblet cells density, presence of villous atrophy or crypt hypertrophy. We present a method for automatically classifying CLE images into three different classes: normal regions, villous atrophy and crypt hypertrophy. This classification is performed after a features selection process, in which four features are extracted from each image, through the application of homomorphic filtering and border identification through Canny and Sobel operators. Three different classifiers have been tested on a dataset of 67 different images labeled by experts in three classes (normal, VA and CH): linear approach, Naive-Bayes quadratic approach and a standard quadratic analysis, all validated with a ten-fold cross validation. Linear classification achieves 82.09% accuracy (class accuracies: 90.32% for normal villi, 82.35% for VA and 68.42% for CH, sensitivity: 0.68, specificity 1.00), Naive Bayes analysis returns 83.58% accuracy (90.32% for normal villi, 70.59% for VA and 84.21% for CH, sensitivity: 0.84 specificity: 0.92), while the quadratic analysis achieves a final accuracy of 94.03% (96.77% accuracy for normal villi, 94.12% for VA and 89.47% for CH, sensitivity: 0.89, specificity: 0.98).

[Assessment of the validity and utility of the Beijing questionnaire as atool to evaluate for obstructive sleep apnea hypopnea syndrome].

PubMed

Wang, X T; Gao, L M; Xu, W; Ding, X

2016-10-20

Objective: To test the Beijing questionnaire as a means of identifying patients with obstructive sleep apnea hypopnea syndrome（OSAHS）. Method: The Beijing questionnaire is designed as an explorative tool consist of 11 questions for patients with obstructive sleep apnea hypopnea, and is targeted toward key symptoms include snoring, apneas, daytime sleepiness, hypertension and overweight. 1 336 female participants living in communities of age≥40 years and 198 male adult subjects visting clinics were given questionnaires. Finally, 59 female and 198 male subjects underwent sleep studies after factor analysis,reliability check,internal consistency study. The correlation analysis was performed between the scores from the Beijing questionnaire and the apnea-hypopnea index from inlaboratory polysomnography.Receiver operating characteristics were constructed to determine optimal sensitivity and specificity. Twenty-four male subjects were recorded in the sleep laberatory again after operative. Result: Factor analysis reduced 11 questions of scale to four common factors as we have designed: snoring,apneas,other symptoms,risk factors. Cronbach's α coefficient of scale reached 0.7.There were an acceptable level of testretest reliability(r=0.619, P <0.01).The apnea hypopnea indices were significantly correlated with their Beijing questionnaire scores( P <0.01).For wemen,an Beijing questionnaire scroe of 19.5 provided a sensitivity of 74.3% and a specificity of 62.5%.For men,an Beijing questionnaire scroe of 22.5 provided a sensitivity of 90.9% and a specificity of 54.5%. And the postoperative Beijing questionnaire scroes changed with the apnea hypopnea indices. Conclusion: This questionnaire has a good validity and reliability and appears to be valid and sensitive to clinical change. Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.

Quantitative molecular analysis in mantle cell lymphoma.

PubMed

Brízová, H; Hilská, I; Mrhalová, M; Kodet, R

2011-07-01

A molecular analysis has three major roles in modern oncopathology--as an aid in the differential diagnosis, in molecular monitoring of diseases, and in estimation of the potential prognosis. In this report we review the application of the molecular analysis in a group of patients with mantle cell lymphoma (MCL). We demonstrate that detection of the cyclin D1 mRNA level is a molecular marker in 98% of patients with MCL. Cyclin D1 quantitative monitoring is specific and sensitive for the differential diagnosis and for the molecular monitoring of the disease in the bone marrow. Moreover, the dynamics of cyclin D1 in bone marrow reflects the disease development and it predicts the clinical course. We employed the molecular analysis for a precise quantitative detection of proliferation markers, Ki-67, topoisomerase IIalpha, and TPX2, that are described as effective prognostic factors. Using the molecular approach it is possible to measure the proliferation rate in a reproducible, standard way which is an essential prerequisite for using the proliferation activity as a routine clinical tool. Comparing with immunophenotyping we may conclude that the quantitative PCR-based analysis is a useful, reliable, rapid, reproducible, sensitive and specific method broadening our diagnostic tools in hematopathology. In comparison to interphase FISH in paraffin sections quantitative PCR is less technically demanding and less time-consuming and furthermore it is more sensitive in detecting small changes in the mRNA level. Moreover, quantitative PCR is the only technology which provides precise and reproducible quantitative information about the expression level. Therefore it may be used to demonstrate the decrease or increase of a tumor-specific marker in bone marrow in comparison with a previously aspirated specimen. Thus, it has a powerful potential to monitor the course of the disease in correlation with clinical data.

The reliability and validity of video analysis for the assessment of the clinical signs of concussion in Australian football.

PubMed

Makdissi, Michael; Davis, Gavin

2016-10-01

The objective of this study was to determine the reliability and validity of identifying clinical signs of concussion using video analysis in Australian football. Prospective cohort study. All impacts and collisions potentially resulting in a concussion were identified during 2012 and 2013 Australian Football League seasons. Consensus definitions were developed for clinical signs associated with concussion. For intra- and inter-rater reliability analysis, two experienced clinicians independently assessed 102 randomly selected videos on two occasions. Sensitivity, specificity, positive and negative predictive values were calculated based on the diagnosis provided by team medical staff. 212 incidents resulting in possible concussion were identified in 414 Australian Football League games. The intra-rater reliability of the video-based identification of signs associated with concussion was good to excellent. Inter-rater reliability was good to excellent for impact seizure, slow to get up, motor incoordination, ragdoll appearance (2 of 4 analyses), clutching at head and facial injury. Inter-rater reliability for loss of responsiveness and blank and vacant look was only fair and did not reach statistical significance. The feature with the highest sensitivity was slow to get up (87%), but this sign had a low specificity (19%). Other video signs had a high specificity but low sensitivity. Blank and vacant look (100%) and motor incoordination (81%) had the highest positive predictive value. Video analysis may be a useful adjunct to the side-line assessment of a possible concussion. Video analysis however should not replace the need for a thorough multimodal clinical assessment. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Local connected fractal dimension analysis in gill of fish experimentally exposed to toxicants.

PubMed

Manera, Maurizio; Giari, Luisa; De Pasquale, Joseph A; Sayyaf Dezfuli, Bahram

2016-06-01

An operator-neutral method was implemented to objectively assess European seabass, Dicentrarchus labrax (Linnaeus, 1758) gill pathology after experimental exposure to cadmium (Cd) and terbuthylazine (TBA) for 24 and 48h. An algorithm-derived local connected fractal dimension (LCFD) frequency measure was used in this comparative analysis. Canonical variates (CVA) and linear discriminant analysis (LDA) were used to evaluate the discrimination power of the method among exposure classes (unexposed, Cd exposed, TBA exposed). Misclassification, sensitivity and specificity, both with original and cross-validated cases, were determined. LCFDs frequencies enhanced the differences among classes which were visually selected after their means, respective variances and the differences between Cd and TBA exposed means, with respect to unexposed mean, were analyzed by scatter plots. Selected frequencies were then scanned by means of LDA, stepwise analysis, and Mahalanobis distance to detect the most discriminative frequencies out of ten originally selected. Discrimination resulted in 91.7% of cross-validated cases correctly classified (22 out of 24 total cases), with sensitivity and specificity, respectively, of 95.5% (1 false negative with respect to 21 really positive cases) and 75% (1 false positive with respect to 3 really negative cases). CVA with convex hull polygons ensured prompt, visually intuitive discrimination among exposure classes and graphically supported the false positive case. The combined use of semithin sections, which enhanced the visual evaluation of the overall lamellar structure; of LCFD analysis, which objectively detected local variation in complexity, without the possible bias connected to human personnel; and of CVA/LDA, could be an objective, sensitive and specific approach to study fish gill lamellar pathology. Furthermore this approach enabled discrimination with sufficient confidence between exposure classes or pathological states and avoided misdiagnosis. Copyright © 2016 Elsevier B.V. All rights reserved.

Acoustic Radiation Force Impulse Imaging for the Differentiation of Benign and Malignant Lymph Nodes: A Systematic Review and Meta-Analysis.

PubMed

Zhang, Peige; Zhang, Li; Zheng, Shaoping; Yu, Cheng; Xie, Mingxing; Lv, Qing

2016-01-01

To evaluate the overall performance of acoustic radiation force impulse imaging (ARFI) in differentiating between benign and malignant lymph nodes (LNs) by conducting a meta-analysis. PubMed, Embase, Web of Science, the Cochrane Library and the China National Knowledge Infrastructure were comprehensively searched for potential studies through August 13th, 2016. Studies that investigated the diagnostic power of ARFI for the differential diagnosis of benign and malignant LNs by using virtual touch tissue quantification (VTQ) or virtual touch tissue imaging quantification (VTIQ) were collected. The included articles were published in English or Chinese. Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) was used to evaluate the methodological quality. The pooled sensitivity, specificity, and the area under the summary receiver operating characteristic (SROC) curve (AUC) were calculated by means of a bivariate mixed-effects regression model. Meta-regression analysis was performed to identify the potential sources of between study heterogeneity. Fagan plot analysis was used to explore the clinical utilities. Publication bias was assessed using Deek's funnel plot. Nine studies involving 1084 LNs from 929 patients were identified to analyze in the meta-analysis. The summary sensitivity and specificity of ARFI in detecting malignant LNs were 0.87 (95% confidence interval [CI], 0.83-0.91) and 0.88 (95% CI, 0.82-0.92), respectively. The AUC was 0.93 (95% CI, 0.90-0.95). The pooled DOR was 49.59 (95% CI, 26.11-94.15). Deek's funnel plot revealed no significant publication bias. ARFI is a promising tool for the differentiation of benign and malignant LNs with high sensitivity and specificity.

Acoustic Radiation Force Impulse Imaging for the Differentiation of Benign and Malignant Lymph Nodes: A Systematic Review and Meta-Analysis

PubMed Central

Yu, Cheng; Xie, Mingxing; Lv, Qing

2016-01-01

Objective To evaluate the overall performance of acoustic radiation force impulse imaging (ARFI) in differentiating between benign and malignant lymph nodes (LNs) by conducting a meta-analysis. Methods PubMed, Embase, Web of Science, the Cochrane Library and the China National Knowledge Infrastructure were comprehensively searched for potential studies through August 13th, 2016. Studies that investigated the diagnostic power of ARFI for the differential diagnosis of benign and malignant LNs by using virtual touch tissue quantification (VTQ) or virtual touch tissue imaging quantification (VTIQ) were collected. The included articles were published in English or Chinese. Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) was used to evaluate the methodological quality. The pooled sensitivity, specificity, and the area under the summary receiver operating characteristic (SROC) curve (AUC) were calculated by means of a bivariate mixed-effects regression model. Meta-regression analysis was performed to identify the potential sources of between study heterogeneity. Fagan plot analysis was used to explore the clinical utilities. Publication bias was assessed using Deek’s funnel plot. Results Nine studies involving 1084 LNs from 929 patients were identified to analyze in the meta-analysis. The summary sensitivity and specificity of ARFI in detecting malignant LNs were 0.87 (95% confidence interval [CI], 0.83–0.91) and 0.88 (95% CI, 0.82–0.92), respectively. The AUC was 0.93 (95% CI, 0.90–0.95). The pooled DOR was 49.59 (95% CI, 26.11–94.15). Deek’s funnel plot revealed no significant publication bias. Conclusion ARFI is a promising tool for the differentiation of benign and malignant LNs with high sensitivity and specificity. PMID:27855188

Optical Coherence Tomography Minimum Intensity as an Objective Measure for the Detection of Hydroxychloroquine Toxicity.

PubMed

Allahdina, Ali M; Stetson, Paul F; Vitale, Susan; Wong, Wai T; Chew, Emily Y; Ferris, Fredrick L; Sieving, Paul A; Cukras, Catherine

2018-04-01

As optical coherence tomography (OCT) minimum intensity (MI) analysis provides a quantitative assessment of changes in the outer nuclear layer (ONL), we evaluated the ability of OCT-MI analysis to detect hydroxychloroquine toxicity. Fifty-seven predominantly female participants (91.2% female; mean age, 55.7 ± 10.4 years; mean time on hydroxychloroquine, 15.0 ± 7.5 years) were enrolled in a case-control study and categorized into affected (i.e., with toxicity, n = 19) and unaffected (n = 38) groups using objective multifocal electroretinographic (mfERG) criteria. Spectral-domain OCT scans of the macula were analyzed and OCT-MI values quantitated for each subfield of the Early Treatment Diabetic Retinopathy Study (ETDRS) grid. A two-sample U-test and a cross-validation approach were used to assess the sensitivity and specificity of toxicity detection according to OCT-MI criteria. The medians of the OCT-MI values in all nine of the ETDRS subfields were significantly elevated in the affected group relative to the unaffected group (P < 0.005 for all comparisons), with the largest difference found for the inner inferior subfield (P < 0.0001). The receiver operating characteristic analysis of median MI values of the inner inferior subfields showed high sensitivity and high specificity in the detection of toxicity with area under the curve = 0.99. Retinal changes secondary to hydroxychloroquine toxicity result in increased OCT reflectivity in the ONL that can be detected and quantitated using OCT-MI analysis. Analysis of OCT-MI values demonstrates high sensitivity and specificity for detecting the presence of hydroxychloroquine toxicity in this cohort and may contribute additionally to current screening practices.

Optical Coherence Tomography Minimum Intensity as an Objective Measure for the Detection of Hydroxychloroquine Toxicity

PubMed Central

Allahdina, Ali M.; Stetson, Paul F.; Vitale, Susan; Wong, Wai T.; Chew, Emily Y.; Ferris, Fredrick L.; Sieving, Paul A.

2018-01-01

Purpose As optical coherence tomography (OCT) minimum intensity (MI) analysis provides a quantitative assessment of changes in the outer nuclear layer (ONL), we evaluated the ability of OCT-MI analysis to detect hydroxychloroquine toxicity. Methods Fifty-seven predominantly female participants (91.2% female; mean age, 55.7 ± 10.4 years; mean time on hydroxychloroquine, 15.0 ± 7.5 years) were enrolled in a case-control study and categorized into affected (i.e., with toxicity, n = 19) and unaffected (n = 38) groups using objective multifocal electroretinographic (mfERG) criteria. Spectral-domain OCT scans of the macula were analyzed and OCT-MI values quantitated for each subfield of the Early Treatment Diabetic Retinopathy Study (ETDRS) grid. A two-sample U-test and a cross-validation approach were used to assess the sensitivity and specificity of toxicity detection according to OCT-MI criteria. Results The medians of the OCT-MI values in all nine of the ETDRS subfields were significantly elevated in the affected group relative to the unaffected group (P < 0.005 for all comparisons), with the largest difference found for the inner inferior subfield (P < 0.0001). The receiver operating characteristic analysis of median MI values of the inner inferior subfields showed high sensitivity and high specificity in the detection of toxicity with area under the curve = 0.99. Conclusions Retinal changes secondary to hydroxychloroquine toxicity result in increased OCT reflectivity in the ONL that can be detected and quantitated using OCT-MI analysis. Analysis of OCT-MI values demonstrates high sensitivity and specificity for detecting the presence of hydroxychloroquine toxicity in this cohort and may contribute additionally to current screening practices. PMID:29677357

The diagnostic performance of perfusion MRI for differentiating glioma recurrence from pseudoprogression: A meta-analysis.

PubMed

Wan, Bing; Wang, Siqi; Tu, Mengqi; Wu, Bo; Han, Ping; Xu, Haibo

2017-03-01

The purpose of this meta-analysis was to evaluate the diagnostic accuracy of perfusion magnetic resonance imaging (MRI) as a method for differentiating glioma recurrence from pseudoprogression. The PubMed, Embase, Cochrane Library, and Chinese Biomedical databases were searched comprehensively for relevant studies up to August 3, 2016 according to specific inclusion and exclusion criteria. The quality of the included studies was assessed according to the quality assessment of diagnostic accuracy studies (QUADAS-2). After performing heterogeneity and threshold effect tests, pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were calculated. Publication bias was evaluated visually by a funnel plot and quantitatively using Deek funnel plot asymmetry test. The area under the summary receiver operating characteristic curve was calculated to demonstrate the diagnostic performance of perfusion MRI. Eleven studies covering 416 patients and 418 lesions were included in this meta-analysis. The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 0.88 (95% confidence interval [CI] 0.84-0.92), 0.77 (95% CI 0.69-0.84), 3.93 (95% CI 2.83-5.46), 0.16 (95% CI 0.11-0.22), and 27.17 (95% CI 14.96-49.35), respectively. The area under the summary receiver operating characteristic curve was 0.8899. There was no notable publication bias. Sensitivity analysis showed that the meta-analysis results were stable and credible. While perfusion MRI is not the ideal diagnostic method for differentiating glioma recurrence from pseudoprogression, it could improve diagnostic accuracy. Therefore, further research on combining perfusion MRI with other imaging modalities is warranted.

Ultrasound for Distal Forearm Fracture: A Systematic Review and Diagnostic Meta-Analysis

PubMed Central

Douma-den Hamer, Djoke; Blanker, Marco H.; Edens, Mireille A.; Buijteweg, Lonneke N.; Boomsma, Martijn F.; van Helden, Sven H.; Mauritz, Gert-Jan

2016-01-01

Study Objective To determine the diagnostic accuracy of ultrasound for detecting distal forearm fractures. Methods A systematic review and diagnostic meta-analysis was performed according to the PRISMA statement. We searched MEDLINE, Web of Science and the Cochrane Library from inception to September 2015. All prospective studies of the diagnostic accuracy of ultrasound versus radiography as the reference standard were included. We excluded studies with a retrospective design and those with evidence of verification bias. We assessed the methodological quality of the included studies with the QUADAS-2 tool. We performed a meta-analysis of studies evaluating ultrasound to calculate the pooled sensitivity and specificity with 95% confidence intervals (CI95%) using a bivariate model with random effects. Subgroup and sensitivity analysis were used to examine the effect of methodological differences and other study characteristics. Results Out of 867 publications we included 16 studies with 1,204 patients and 641 fractures. The pooled test characteristics for ultrasound were: sensitivity 97% (CI95% 93–99%), specificity 95% (CI95% 89–98%), positive likelihood ratio (LR) 20.0 (8.5–47.2) and negative LR 0.03 (0.01–0.08). The corresponding pooled diagnostic odds ratio (DOR) was 667 (142–3,133). Apparent differences were shown for method of viewing, with the 6-view method showing higher specificity, positive LR, and DOR, compared to the 4-view method. Conclusion The present meta-analysis showed that ultrasound has a high accuracy for the diagnosis of distal forearm fractures in children when used by proper viewing method. Based on this, ultrasound should be considered a reliable alternative, which has the advantages of being radiation free. PMID:27196439

Falls Risk Prediction for Older Inpatients in Acute Care Medical Wards: Is There an Interest to Combine an Early Nurse Assessment and the Artificial Neural Network Analysis?

PubMed

Beauchet, O; Noublanche, F; Simon, R; Sekhon, H; Chabot, J; Levinoff, E J; Kabeshova, A; Launay, C P

2018-01-01

Identification of the risk of falls is important among older inpatients. This study aims to examine performance criteria (i.e.; sensitivity, specificity, positive predictive value, negative predictive value and accuracy) for fall prediction resulting from a nurse assessment and an artificial neural networks (ANNs) analysis in older inpatients hospitalized in acute care medical wards. A total of 848 older inpatients (mean age, 83.0±7.2 years; 41.8% female) admitted to acute care medical wards in Angers University hospital (France) were included in this study using an observational prospective cohort design. Within 24 hours after admission of older inpatients, nurses performed a bedside clinical assessment. Participants were separated into non-fallers and fallers (i.e.; ≥1 fall during hospitalization stay). The analysis was conducted using three feed forward ANNs (multilayer perceptron [MLP], averaged neural network, and neuroevolution of augmenting topologies [NEAT]). Seventy-three (8.6%) participants fell at least once during their hospital stay. ANNs showed a high specificity, regardless of which ANN was used, and the highest value reported was with MLP (99.8%). In contrast, sensitivity was lower, with values ranging between 98.4 to 14.8%. MLP had the highest accuracy (99.7). Performance criteria for fall prediction resulting from a bedside nursing assessment and an ANNs analysis was associated with a high specificity but a low sensitivity, suggesting that this combined approach should be used more as a diagnostic test than a screening test when considering older inpatients in acute care medical ward.

Can time-averaged flow boundary conditions be used to meet the clinical timeline for Fontan surgical planning?

PubMed

Wei, Zhenglun Alan; Trusty, Phillip M; Tree, Mike; Haggerty, Christopher M; Tang, Elaine; Fogel, Mark; Yoganathan, Ajit P

2017-01-04

Cardiovascular simulations have great potential as a clinical tool for planning and evaluating patient-specific treatment strategies for those suffering from congenital heart diseases, specifically Fontan patients. However, several bottlenecks have delayed wider deployment of the simulations for clinical use; the main obstacle is simulation cost. Currently, time-averaged clinical flow measurements are utilized as numerical boundary conditions (BCs) in order to reduce the computational power and time needed to offer surgical planning within a clinical time frame. Nevertheless, pulsatile blood flow is observed in vivo, and its significant impact on numerical simulations has been demonstrated. Therefore, it is imperative to carry out a comprehensive study analyzing the sensitivity of using time-averaged BCs. In this study, sensitivity is evaluated based on the discrepancies between hemodynamic metrics calculated using time-averaged and pulsatile BCs; smaller discrepancies indicate less sensitivity. The current study incorporates a comparison between 3D patient-specific CFD simulations using both the time-averaged and pulsatile BCs for 101 Fontan patients. The sensitivity analysis involves two clinically important hemodynamic metrics: hepatic flow distribution (HFD) and indexed power loss (iPL). Paired demographic group comparisons revealed that HFD sensitivity is significantly different between single and bilateral superior vena cava cohorts but no other demographic discrepancies were observed for HFD or iPL. Multivariate regression analyses show that the best predictors for sensitivity involve flow pulsatilities, time-averaged flow rates, and geometric characteristics of the Fontan connection. These predictors provide patient-specific guidelines to determine the effectiveness of analyzing patient-specific surgical options with time-averaged BCs within a clinical time frame. Copyright © 2016 Elsevier Ltd. All rights reserved.

Skeletal Mechanism Generation of Surrogate Jet Fuels for Aeropropulsion Modeling

NASA Astrophysics Data System (ADS)

Sung, Chih-Jen; Niemeyer, Kyle E.

2010-05-01

A novel implementation for the skeletal reduction of large detailed reaction mechanisms using the directed relation graph with error propagation and sensitivity analysis (DRGEPSA) is developed and presented with skeletal reductions of two important hydrocarbon components, n-heptane and n-decane, relevant to surrogate jet fuel development. DRGEPSA integrates two previously developed methods, directed relation graph-aided sensitivity analysis (DRGASA) and directed relation graph with error propagation (DRGEP), by first applying DRGEP to efficiently remove many unimportant species prior to sensitivity analysis to further remove unimportant species, producing an optimally small skeletal mechanism for a given error limit. It is illustrated that the combination of the DRGEP and DRGASA methods allows the DRGEPSA approach to overcome the weaknesses of each previous method, specifically that DRGEP cannot identify all unimportant species and that DRGASA shields unimportant species from removal.

DOD Product Support Business Case Analysis Guidebook

DTIC Science & Technology

2011-04-01

Mitigation Plans ................................................................................................ 30 4.8 Sensitivity Analysis...Product Support BCA concludes with a recommendation and associated specific actions and an implementation plan to achieve stated organizational...primary executer of the actions and recommendations derived out of the BCA. Within the program office, the PSM has the responsibility to plan

Ultrasonography for endoleak detection after endoluminal abdominal aortic aneurysm repair.

PubMed

Abraha, Iosief; Luchetta, Maria Laura; De Florio, Rita; Cozzolino, Francesco; Casazza, Giovanni; Duca, Piergiorgio; Parente, Basso; Orso, Massimiliano; Germani, Antonella; Eusebi, Paolo; Montedori, Alessandro

2017-06-09

People with abdominal aortic aneurysm who receive endovascular aneurysm repair (EVAR) need lifetime surveillance to detect potential endoleaks. Endoleak is defined as persistent blood flow within the aneurysm sac following EVAR. Computed tomography (CT) angiography is considered the reference standard for endoleak surveillance. Colour duplex ultrasound (CDUS) and contrast-enhanced CDUS (CE-CDUS) are less invasive but considered less accurate than CT. To determine the diagnostic accuracy of colour duplex ultrasound (CDUS) and contrast-enhanced-colour duplex ultrasound (CE-CDUS) in terms of sensitivity and specificity for endoleak detection after endoluminal abdominal aortic aneurysm repair (EVAR). We searched MEDLINE, Embase, LILACS, ISI Conference Proceedings, Zetoc, and trial registries in June 2016 without language restrictions and without use of filters to maximize sensitivity. Any cross-sectional diagnostic study evaluating participants who received EVAR by both ultrasound (with or without contrast) and CT scan assessed at regular intervals. Two pairs of review authors independently extracted data and assessed quality of included studies using the QUADAS 1 tool. A third review author resolved discrepancies. The unit of analysis was number of participants for the primary analysis and number of scans performed for the secondary analysis. We carried out a meta-analysis to estimate sensitivity and specificity of CDUS or CE-CDUS using a bivariate model. We analysed each index test separately. As potential sources of heterogeneity, we explored year of publication, characteristics of included participants (age and gender), direction of the study (retrospective, prospective), country of origin, number of CDUS operators, and ultrasound manufacturer. We identified 42 primary studies with 4220 participants. Twenty studies provided accuracy data based on the number of individual participants (seven of which provided data with and without the use of contrast). Sixteen of these studies evaluated the accuracy of CDUS. These studies were generally of moderate to low quality: only three studies fulfilled all the QUADAS items; in six (40%) of the studies, the delay between the tests was unclear or longer than four weeks; in eight (50%), the blinding of either the index test or the reference standard was not clearly reported or was not performed; and in two studies (12%), the interpretation of the reference standard was not clearly reported. Eleven studies evaluated the accuracy of CE-CDUS. These studies were of better quality than the CDUS studies: five (45%) studies fulfilled all the QUADAS items; four (36%) did not report clearly the blinding interpretation of the reference standard; and two (18%) did not clearly report the delay between the two tests.Based on the bivariate model, the summary estimates for CDUS were 0.82 (95% confidence interval (CI) 0.66 to 0.91) for sensitivity and 0.93 (95% CI 0.87 to 0.96) for specificity whereas for CE-CDUS the estimates were 0.94 (95% CI 0.85 to 0.98) for sensitivity and 0.95 (95% CI 0.90 to 0.98) for specificity. Regression analysis showed that CE-CDUS was superior to CDUS in terms of sensitivity (LR Chi 2 = 5.08, 1 degree of freedom (df); P = 0.0242 for model improvement).Seven studies provided estimates before and after administration of contrast. Sensitivity before contrast was 0.67 (95% CI 0.47 to 0.83) and after contrast was 0.97 (95% CI 0.92 to 0.99). The improvement in sensitivity with of contrast use was statistically significant (LR Chi 2 = 13.47, 1 df; P = 0.0002 for model improvement).Regression testing showed evidence of statistically significant effect bias related to year of publication and study quality within individual participants based CDUS studies. Sensitivity estimates were higher in the studies published before 2006 than the estimates obtained from studies published in 2006 or later (P < 0.001); and studies judged as low/unclear quality provided higher estimates in sensitivity. When regression testing was applied to the individual based CE-CDUS studies, none of the items, namely direction of the study design, quality, and age, were identified as a source of heterogeneity.Twenty-two studies provided accuracy data based on number of scans performed (of which four provided data with and without the use of contrast). Analysis of the studies that provided scan based data showed similar results. Summary estimates for CDUS (18 studies) showed 0.72 (95% CI 0.55 to 0.85) for sensitivity and 0.95 (95% CI 0.90 to 0.96) for specificity whereas summary estimates for CE-CDUS (eight studies) were 0.91 (95% CI 0.68 to 0.98) for sensitivity and 0.89 (95% CI 0.71 to 0.96) for specificity. This review demonstrates that both ultrasound modalities (with or without contrast) showed high specificity. For ruling in endoleaks, CE-CDUS appears superior to CDUS. In an endoleak surveillance programme CE-CDUS can be introduced as a routine diagnostic modality followed by CT scan only when the ultrasound is positive to establish the type of endoleak and the subsequent therapeutic management.

Improvement of the cost-benefit analysis algorithm for high-rise construction projects

NASA Astrophysics Data System (ADS)

Gafurov, Andrey; Skotarenko, Oksana; Plotnikov, Vladimir

2018-03-01

The specific nature of high-rise investment projects entailing long-term construction, high risks, etc. implies a need to improve the standard algorithm of cost-benefit analysis. An improved algorithm is described in the article. For development of the improved algorithm of cost-benefit analysis for high-rise construction projects, the following methods were used: weighted average cost of capital, dynamic cost-benefit analysis of investment projects, risk mapping, scenario analysis, sensitivity analysis of critical ratios, etc. This comprehensive approach helped to adapt the original algorithm to feasibility objectives in high-rise construction. The authors put together the algorithm of cost-benefit analysis for high-rise construction projects on the basis of risk mapping and sensitivity analysis of critical ratios. The suggested project risk management algorithms greatly expand the standard algorithm of cost-benefit analysis in investment projects, namely: the "Project analysis scenario" flowchart, improving quality and reliability of forecasting reports in investment projects; the main stages of cash flow adjustment based on risk mapping for better cost-benefit project analysis provided the broad range of risks in high-rise construction; analysis of dynamic cost-benefit values considering project sensitivity to crucial variables, improving flexibility in implementation of high-rise projects.

Physical examination tests of the shoulder: a systematic review and meta-analysis of diagnostic test performance.

PubMed

Gismervik, Sigmund Ø; Drogset, Jon O; Granviken, Fredrik; Rø, Magne; Leivseth, Gunnar

2017-01-25

Physical examination tests of the shoulder (PETS) are clinical examination maneuvers designed to aid the assessment of shoulder complaints. Despite more than 180 PETS described in the literature, evidence of their validity and usefulness in diagnosing the shoulder is questioned. This meta-analysis aims to use diagnostic odds ratio (DOR) to evaluate how much PETS shift overall probability and to rank the test performance of single PETS in order to aid the clinician's choice of which tests to use. This study adheres to the principles outlined in the Cochrane guidelines and the PRISMA statement. A fixed effect model was used to assess the overall diagnostic validity of PETS by pooling DOR for different PETS with similar biomechanical rationale when possible. Single PETS were assessed and ranked by DOR. Clinical performance was assessed by sensitivity, specificity, accuracy and likelihood ratio. Six thousand nine-hundred abstracts and 202 full-text articles were assessed for eligibility; 20 articles were eligible and data from 11 articles could be included in the meta-analysis. All PETS for SLAP (superior labral anterior posterior) lesions pooled gave a DOR of 1.38 [1.13, 1.69]. The Supraspinatus test for any full thickness rotator cuff tear obtained the highest DOR of 9.24 (sensitivity was 0.74, specificity 0.77). Compression-Rotation test obtained the highest DOR (6.36) among single PETS for SLAP lesions (sensitivity 0.43, specificity 0.89) and Hawkins test obtained the highest DOR (2.86) for impingement syndrome (sensitivity 0.58, specificity 0.67). No single PETS showed superior clinical test performance. The clinical performance of single PETS is limited. However, when the different PETS for SLAP lesions were pooled, we found a statistical significant change in post-test probability indicating an overall statistical validity. We suggest that clinicians choose their PETS among those with the highest pooled DOR and to assess validity to their own specific clinical settings, review the inclusion criteria of the included primary studies. We further propose that future studies on the validity of PETS use randomized research designs rather than the accuracy design relying less on well-established gold standard reference tests and efficient treatment options.

Assessment of insulin sensitivity from measurements in fasting state and during an oral glucose tolerance test in obese children.

PubMed

Atabek, Mehmet Emre; Pirgon, Ozgur

2007-02-01

Few previous studies have examined the validity of the fasting glucose-to-insulin ratio (FGIR), homeostasis model assessment of insulin resistance (HOMA-IR) and quantitative insulin-sensitivity check index (QUICKI) in pediatric populations. To compare simple indices of insulin resistance calculated from fasting glucose and insulin levels with insulin sensitivity indices (area under the response curve [AUCinsulin], insulin sensitivity index [ISI-compositeL) determined by oral glucose tolerance testing (OGTT) in obese children. One hundred and forty-eight obese children and adolescents (86 girls and 62 boys, mean age: 10.86 +/- 3.08 years, mean body mass index (BMI): 27.7 +/- 4.2) participated in the study. OGTT was performed in all participants. After glucose and insulin measurements from OGTT, the children were divided into two groups according to the presence or absence of insulin resistance. Insulin sensitivity indices obtained from the OGTT were compared between the groups. The total plasma glucose response and insulin secretion were evaluated from the AUC estimated by the trapezoid rule. Cut-off points, and sensitivity and specificity calculations were based on insulin resistance with receiver operating characteristic curve (ROC) analysis. The prevalence of insulin resistance, glucose intolerance and dyslipidemia was 37.1%, 24.3% and 54% in obese children, respectively. The groups consisted of 93 children without insulin resistance (54 girls and 39 boys; mean age: 10.5 +/- 3.3 years; mean BMI: 27.0 +/- 4.2) and 55 children with insulin resistance (32 girls and 23 boys; mean age: 11.4 +/- 2.5 years; mean BMI: 27.9 +/- 3.9). There were significant differences in mean FGIR (10.0 +/- 7.2 vs 5.6 +/- 2.8, p < 0.001), HOMA-IR (3.2 +/- 2.3 vs 4.9 +/- 2.3, p < 0.001) and QUICKI (0.33 +/- 0.03 vs 0.30 +/- 0.02, p < 0.001) between the groups. The cut-off points for diagnosis of insulin resistance were < 5.6 for FGIR (sensitivity 61.8, specificity 76.3), > 2.7 for HOMA-IR (sensitivity 80, specificity 59.1), and < 0.328 for QUICKI (sensitivity 80, specificity 60.2). Indices derived from fasting samples for diagnosis of insulin sensitivity are reliable criteria in obese children and adolescents. HOMA-IR and QUICKI appeared to have similar sensitivity and specificity and to have higher sensitivity than FGIR.

Sensitivity Analysis and Requirements for Temporally and Spatially Resolved Thermometry Using Neutron Resonance Spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernandez, Juan Carlos; Barnes, Cris William; Mocko, Michael Jeffrey

This report is intended to examine the use of neutron resonance spectroscopy (NRS) to make time- dependent and spatially-resolved temperature measurements of materials in extreme conditions. Specifically, the sensitivities of the temperature estimate on neutron-beam and diagnostic parameters is examined. Based on that examination, requirements are set on a pulsed neutron-source and diagnostics to make a meaningful measurement.

Studentized continuous wavelet transform (t-CWT) in the analysis of individual ERPs: real and simulated EEG data

PubMed Central

Real, Ruben G. L.; Kotchoubey, Boris; Kübler, Andrea

2014-01-01

This study aimed at evaluating the performance of the Studentized Continuous Wavelet Transform (t-CWT) as a method for the extraction and assessment of event-related brain potentials (ERP) in data from a single subject. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) of the t-CWT were assessed and compared to a variety of competing procedures using simulated EEG data at six low signal-to-noise ratios. Results show that the t-CWT combines high sensitivity and specificity with favorable PPV and NPV. Applying the t-CWT to authentic EEG data obtained from 14 healthy participants confirmed its high sensitivity. The t-CWT may thus be well suited for the assessment of weak ERPs in single-subject settings. PMID:25309308

Studentized continuous wavelet transform (t-CWT) in the analysis of individual ERPs: real and simulated EEG data.

PubMed

Real, Ruben G L; Kotchoubey, Boris; Kübler, Andrea

2014-01-01

This study aimed at evaluating the performance of the Studentized Continuous Wavelet Transform (t-CWT) as a method for the extraction and assessment of event-related brain potentials (ERP) in data from a single subject. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) of the t-CWT were assessed and compared to a variety of competing procedures using simulated EEG data at six low signal-to-noise ratios. Results show that the t-CWT combines high sensitivity and specificity with favorable PPV and NPV. Applying the t-CWT to authentic EEG data obtained from 14 healthy participants confirmed its high sensitivity. The t-CWT may thus be well suited for the assessment of weak ERPs in single-subject settings.

Serum biomarkers as predictors of long-term outcome in severe traumatic brain injury: analysis from a randomized placebo-controlled Phase II clinical trial.

PubMed

Raheja, Amol; Sinha, Sumit; Samson, Neha; Bhoi, Sanjeev; Subramanian, Arulselvi; Sharma, Pushpa; Sharma, Bhawani Shankar

2016-09-01

OBJECTIVE There has been increased interest in the potential importance of biochemical parameters as predictors of outcome in severe traumatic brain injury (sTBI). METHODS Of 107 patients with sTBI (age 18-65 years with a Glasgow Coma Scale score of 4-8 presenting within 8 hours after injury) who were randomized for a placebo-controlled Phase II trial of progesterone with or without hypothermia, the authors serially analyzed serum biomarkers (S100-B, glial fibrillary acidic protein [GFAP], neuron-specific enolase [NSE], tumor necrosis factor-α, interleukin-6 [IL-6], estrogen [Eg], and progesterone [Pg]). This analysis was performed using the sandwich enzyme-linked immunosorbent assay technique at admission and 7 days later for 86 patients, irrespective of assigned group. The long-term predictive values of serum biomarkers for dichotomized Glasgow Outcome Scale (GOS) score, functional independence measure, and survival status at 6 and 12 months were analyzed using an adjusted binary logistic regression model and receiver operating characteristic curve. RESULTS A favorable GOS score (4-5) at 1 year was predicted by higher admission IL-6 (above 108.36 pg/ml; area under the curve [AUC] 0.69, sensitivity 52%, and specificity 78.6%) and Day 7 Pg levels (above 3.15 ng/ml; AUC 0.79, sensitivity 70%, and specificity 92.9%). An unfavorable GOS score (1-3) at 1 year was predicted by higher Day 7 GFAP levels (above 9.50 ng/ml; AUC 0.82, sensitivity 78.6%, and specificity 82.4%). Survivors at 1 year had significantly higher Day 7 Pg levels (above 3.15 ng/ml; AUC 0.78, sensitivity 66.7%, and specificity 90.9%). Nonsurvivors at 1 year had significantly higher Day 7 GFAP serum levels (above 11.14 ng/ml; AUC 0.81, sensitivity 81.8%, and specificity 88.9%) and Day 7 IL-6 serum levels (above 71.26 pg/ml; AUC 0.87, sensitivity 81.8%, and specificity 87%). In multivariate logistic regression analysis, independent predictors of outcome at 1 year were serum levels of Day 7 Pg (favorable GOS-OR 3.24, CI 1.5-7, p = 0.003; and favorable survival-OR 2, CI 1.2-3.5, p = 0.01); admission IL-6 (favorable GOS-OR 1.04, CI 1.00-1.08, p = 0.04); and Day 7 GFAP (unfavorable GOS-OR 0.79, CI 0.65-0.95, p = 0.01; and unfavorable survival-OR 0.80, CI 0.66-0.96, p = 0.01). CONCLUSIONS Serial Pg, GFAP, and IL-6 monitoring could aid in prognosticating outcomes in patients with acute sTBI. A cause and effect relationship or a mere association of these biomarkers to outcome needs to be further studied for better understanding of the pathophysiology of sTBI and for choosing potential therapeutic targets. Clinical trial registration no.: CTRI/2009/091/000893 ( http://www.ctri.nic.in ).

Sensitive and specific detection of early gastric cancer with DNA methylation analysis of gastric washes.

PubMed

Watanabe, Yoshiyuki; Kim, Hyun Soo; Castoro, Ryan J; Chung, Woonbok; Estecio, Marcos R H; Kondo, Kimie; Guo, Yi; Ahmed, Saira S; Toyota, Minoru; Itoh, Fumio; Suk, Ki Tae; Cho, Mee-Yon; Shen, Lanlan; Jelinek, Jaroslav; Issa, Jean-Pierre J

2009-06-01

Aberrant DNA methylation is an early and frequent process in gastric carcinogenesis and could be useful for detection of gastric neoplasia. We hypothesized that methylation analysis of DNA recovered from gastric washes could be used to detect gastric cancer. We studied 51 candidate genes in 7 gastric cancer cell lines and 24 samples (training set) and identified 6 for further studies. We examined the methylation status of these genes in a test set consisting of 131 gastric neoplasias at various stages. Finally, we validated the 6 candidate genes in a different population of 40 primary gastric cancer samples and 113 nonneoplastic gastric mucosa samples. Six genes (MINT25, RORA, GDNF, ADAM23, PRDM5, MLF1) showed frequent differential methylation between gastric cancer and normal mucosa in the training, test, and validation sets. GDNF and MINT25 were most sensitive molecular markers of early stage gastric cancer, whereas PRDM5 and MLF1 were markers of a field defect. There was a close correlation (r = 0.5-0.9, P = .03-.001) between methylation levels in tumor biopsy and gastric washes. MINT25 methylation had the best sensitivity (90%), specificity (96%), and area under the receiver operating characteristic curve (0.961) in terms of tumor detection in gastric washes. These findings suggest MINT25 is a sensitive and specific marker for screening in gastric cancer. Additionally, we have developed a new method for gastric cancer detection by DNA methylation in gastric washes.

Low sensitivity of implant sonication when screening for infection in revision surgery

PubMed Central

Van Diek, Floor M; Albers, Christiaan G M; Van Hooff, Miranda L; Meis, Jacques F; Goosen, Jon H M

2017-01-01

Background and purpose Prosthetic-joint infection (PJI) is the most serious complication of arthroplasty, and accurate identification of a potentially responsible microorganism is essential for successful antibiotic treatment. We therefore determined the diagnostic accuracy of sonication and compared it with tissue culture as a screening tool in detecting prosthetic joint infection in revision arthroplasty. Patients and methods 252 consecutive revision arthroplasty cases were enrolled. These cases were determined as being suspected or unsuspected of having infection according to standard criteria. Perioperatively, 6 periprosthetic interface tissue biopsies were obtained from each patient and the implants removed were sonicated. The sensitivity and specificity of periprosthetic tissue culture and sonication fluid cultures were determined. Results Preoperatively, 75 revision cases were classified as having PJI (33 early and 42 late) and 177 were unsuspected of having infection. Compared with tissue culture, the sensitivity of the sonication fluid analysis was low: 0.47 (95% CI: 0.35–0.59) for sonication as compared to 0.68 (95% CI: 0.56–0.78) for tissue culture. The specificity of the sonication fluid analysis was higher than that for tissue culture: 0.99 (95% CI: 0.96–1.0) as compared to 0.80 (95% CI: 0.74–0.86). Interpretation Sonication is a highly specific test for diagnosis of PJI. However, due to the low sensitivity, a negative sonication result does not rule out the presence of PJI. Thus, sonication is not of value for screening of microorganisms during revision surgery. PMID:28287012

Species-specific diagnostic assays for Bonamia ostreae and B. exitiosa in European flat oyster Ostrea edulis: conventional, real-time and multiplex PCR.

PubMed

Ramilo, Andrea; Navas, J Ignacio; Villalba, Antonio; Abollo, Elvira

2013-05-27

Bonamia ostreae and B. exitiosa have caused mass mortalities of various oyster species around the world and co-occur in some European areas. The World Organisation for Animal Health (OIE) has included infections with both species in the list of notifiable diseases. However, official methods for species-specific diagnosis of either parasite have certain limitations. In this study, new species-specific conventional PCR (cPCR) and real-time PCR techniques were developed to diagnose each parasite species. Moreover, a multiplex PCR method was designed to detect both parasites in a single assay. The analytical sensitivity and specificity of each new method were evaluated. These new procedures were compared with 2 OIE-recommended methods, viz. standard histology and PCR-RFLP. The new procedures showed higher sensitivity than the OIE recommended ones for the diagnosis of both species. The sensitivity of tests with the new primers was higher using oyster gills and gonad tissue, rather than gills alone. The lack of a 'gold standard' prevented accurate estimation of sensitivity and specificity of the new methods. The implementation of statistical tools (maximum likelihood method) for the comparison of the diagnostic tests showed the possibility of false positives with the new procedures, although the absence of a gold standard precluded certainty. Nevertheless, all procedures showed negative results when used for the analysis of oysters from a Bonamia-free area.

Evaluation of clinical methods for diagnosing bacterial vaginosis.

PubMed

Gutman, Robert E; Peipert, Jeffrey F; Weitzen, Sherry; Blume, Jeffrey

2005-03-01

To determine whether the current clinical criteria for diagnosing bacterial vaginosis can be simplified by using 2 clinical criteria rather than the standard 3 of 4 criteria (Amsel's criteria). This was a prospective observational study of 269 women undergoing a vaginal examination in the Women's Primary Care Center, Division of Research, or Colposcopy Clinic at Women & Infants Hospital. All 4 clinical criteria for diagnosing bacterial vaginosis were collected, and Gram stain was used as the gold standard. Sensitivity and specificity were calculated for each individual criterion, combinations of criteria, and a colorimetric pH and amine card. Receiver operating characteristic curve was generated to estimate the preferred pH and percentage of clue cells for diagnosing bacterial vaginosis. The prevalence of bacterial vaginosis in our study population was 38.7%. Vaginal pH was the most sensitive of all the criteria, at 89%, and a positive amine odor was the individual criteria with the highest specificity, at 93%. Similar specificity was seen with combinations of 2 criteria and Amsel's criteria. Receiver operating characteristic curve analysis yielded a preferred pH and percentage of clue cells of 5.0 and 20%, respectively. However, a pH of 4.5 or greater improves sensitivity with minimal loss of specificity. The clinical criteria for diagnosing bacterial vaginosis can be simplified to 2 clinical criteria without loss of sensitivity and specificity.

Processing postmortem specimens with C18-carboxypropylbetaine and analysis by PCR to develop an antemortem test for Mycobacterium avium infections in ducks.

PubMed

Thornton, C G; Cranfield, M R; MacLellan, K M; Brink, T L; Strandberg, J D; Carlin, E A; Torrelles, J B; Maslow, J N; Hasson, J L; Heyl, D M; Sarro, S J; Chatterjee, D; Passen, S

1999-03-01

Mycobacterium avium is the causative agent of the avian mycobacteriosis commonly known as avian tuberculosis (ATB). This infection causes disseminated disease, is difficult to diagnose, and is of serious concern because it causes significant mortality in birds. A new method was developed for processing specimens for an antemortem screening test for ATB. This novel method uses the zwitterionic detergent C18-carboxypropylbetaine (CB-18). Blood, bone marrow, bursa, and fecal specimens from 28 ducks and swabs of 20 lesions were processed with CB-18 for analysis by smear, culture, and polymerase chain reaction (PCR). Postmortem examination confirmed nine of these birds as either positive or highly suspect for disseminated disease. The sensitivities of smear, culture, and PCR, relative to postmortem analysis and independent of specimen type, were 44.4%, 88.9%, and 100%, respectively, and the specificities were 84.2%, 57.9%, and 15.8%, respectively. Reductions in specificity were due primarily to results among fecal specimens. However, these results were clustered among a subset of birds, suggesting that these tests actually identified birds in early stages of the disease. Restriction fragment length polymorphism mapping identified one strain of M. avium (serotype 1) that was isolated from lesions, bursa, bone marrow, blood, and feces of all but three of the culture-positive birds. In birds with confirmed disease, blood had the lowest sensitivity and the highest specificity by all diagnostic methods. Swabs of lesions provided the highest sensitivity by smear and culture (33.3% and 77.8%, respectively), whereas fecal specimens had the highest sensitivity by PCR (77.8%). The results of this study indicate that processing fecal specimens with CB-18, followed by PCR analysis, may provide a valuable first step for monitoring the presence of ATB in birds.

Accuracy of urinary human papillomavirus testing for presence of cervical HPV: systematic review and meta-analysis

PubMed Central

Pathak, Neha; Dodds, Julie; Khan, Khalid

2014-01-01

Objective To determine the accuracy of testing for human papillomavirus (HPV) DNA in urine in detecting cervical HPV in sexually active women. Design Systematic review and meta-analysis. Data sources Searches of electronic databases from inception until December 2013, checks of reference lists, manual searches of recent issues of relevant journals, and contact with experts. Eligibility criteria Test accuracy studies in sexually active women that compared detection of urine HPV DNA with detection of cervical HPV DNA. Data extraction and synthesis Data relating to patient characteristics, study context, risk of bias, and test accuracy. 2×2 tables were constructed and synthesised by bivariate mixed effects meta-analysis. Results 16 articles reporting on 14 studies (1443 women) were eligible for meta-analysis. Most used commercial polymerase chain reaction methods on first void urine samples. Urine detection of any HPV had a pooled sensitivity of 87% (95% confidence interval 78% to 92%) and specificity of 94% (95% confidence interval 82% to 98%). Urine detection of high risk HPV had a pooled sensitivity of 77% (68% to 84%) and specificity of 88% (58% to 97%). Urine detection of HPV 16 and 18 had a pooled sensitivity of 73% (56% to 86%) and specificity of 98% (91% to 100%). Metaregression revealed an increase in sensitivity when urine samples were collected as first void compared with random or midstream (P=0.004). Limitations The major limitations of this review are the lack of a strictly uniform method for the detection of HPV in urine and the variation in accuracy between individual studies. Conclusions Testing urine for HPV seems to have good accuracy for the detection of cervical HPV, and testing first void urine samples is more accurate than random or midstream sampling. When cervical HPV detection is considered difficult in particular subgroups, urine testing should be regarded as an acceptable alternative. PMID:25232064

Quantitative relationship between the local lymph node assay and human skin sensitization assays.

PubMed

Schneider, K; Akkan, Z

2004-06-01

The local lymph node assay (LLNA) is a new test method which allows for the quantitative assessment of sensitizing potency in the mouse. Here, we investigate the quantitative correlation between results from the LLNA and two human sensitization tests--specifically, human repeat insult patch tests (HRIPTs) and human maximization tests (HMTs). Data for 57 substances were evaluated, of which 46 showed skin sensitizing properties in human tests, whereas 11 yielded negative results in humans. For better comparability data from mouse and human tests were transformed to applied doses per skin area, which ranged over four orders of magnitude for the substances considered. Regression analysis for the 46 human sensitizing substances revealed a significant positive correlation between the LLNA and human tests. The correlation was better between LLNA and HRIPT data (n=23; r=0.77) than between LLNA and HMT data (n=38; r=0.65). The observed scattering of data points is related to various uncertainties, in part associated with insufficiencies of data from older HMT studies. Predominantly negative results in the LLNA for another 11 substances which showed no skin sensitizing activity in human maximization tests further corroborate the correspondence between LLNA and human tests. Based on this analysis, the LLNA can be considered a reliable basis for relative potency assessments for skin sensitizers. Proposals are made for the regulatory exploitation of the LLNA: four potency groups can be established, and assignment of substances to these groups according to the outcome of the LLNA can be used to characterize skin sensitizing potency in substance-specific assessments. Moreover, based on these potency groups, a more adequate consideration of sensitizing substances in preparations becomes possible. It is proposed to replace the current single concentration limit for skin sensitizers in preparations, which leads to an all or nothing classification of a preparation as sensitizing to skin ("R43") in the European Union, by differentiated concentration limits derived from the limits for the four potency groups.

Prevalence of and risk factors for latex sensitization in patients with spina bifida.

PubMed

Bernardini, R; Novembre, E; Lombardi, E; Mezzetti, P; Cianferoni, A; Danti, A D; Mercurella, A; Vierucci, A

1998-11-01

We determined the prevalence of and risk factors for latex sensitization in patients with spina bifida. A total of 59 consecutive subjects 2 to 40 years old with spina bifida answered a questionnaire, and underwent a latex skin prick test and determination of serum IgE specific for latex by RAST CAP radioimmunoassay. We also noted the relationships of total serum IgE skin prick tests to common air and food allergens. In addition, skin prick plus prick tests were also done with fresh foods, including kiwi, pear, orange, almond, pineapple, apple, tomato and banana. Latex sensitization was present in 15 patients (25%) according to the presence of IgE specific to latex, as detected by a skin prick test in 9 and/or RAST CAP in 13. Five latex sensitized patients (33.3%) had clinical manifestations, such as urticaria, conjuctivitis, angioedema, rhinitis and bronchial asthma, while using a latex glove and inflating a latex balloon. Atopy was present in 21 patients (35.6%). In 14 patients (23%) 1 or more skin tests were positive for fresh foods using a prick plus prick technique. Tomato, kiwi, and pear were the most common skin test positive foods. Univariate analysis revealed that a history of 5 or more operations, atopy and positive prick plus prick tests results for pear and kiwi were significantly associated with latex sensitization. Multivariate analysis demonstrated that only atopy and a history of 5 or more operations were significantly and independently associated with latex sensitization. A fourth of the patients with spina bifida were sensitized to latex. Atopy and an elevated number of operations were significant and independent predictors of latex sensitization in these cases.

Loop-mediated isothermal amplification for detection of Staphylococcus aureus in dairy cow suffering from mastitis.

PubMed

Tie, Zhang; Chunguang, Wang; Xiaoyuan, Wei; Xinghua, Zhao; Xiuhui, Zhong

2012-01-01

To develop a rapid detection method of Staphylococcus aureus using loop-mediated isothermal amplification (LAMP), four specific primers were designed according to six distinct sequences of the nuc gene. In addition, the specificity and sensitivity of LAMP were verified and compared with those of PCR. Results showed that the LAMP reaction was completed within 45 min at 62.5°C, and ladder bands were appeared in LAMP products analyzed by gel electrophoresis. After adding 1x SYBR Green l, the positive reaction tube showed green color and the negative reaction tube remained orange, indicating that the LAMP has high specificity. The minimal detectable concentration of LAMP was 1 × 10² CFU/mL and that of PCR was 1 × 10⁴ CFU/mL, indicating that the LAMP was 100 times more sensitive than the PCR. The LAMP method for detection of Staphylococcus aureus has many advantages, such as simple operation, high sensitivity, high specificity, and rapid analysis. Therefore, this method is more suitable for the rapid on-site detection of Staphylococcus aureus.

Tests for Serum Transglutaminase and Endomysial Antibodies Do Not Detect Most Patients With Celiac Disease and Persistent Villous Atrophy on Gluten-free Diets: a Meta-analysis.

PubMed

Silvester, Jocelyn A; Kurada, Satya; Szwajcer, Andrea; Kelly, Ciarán P; Leffler, Daniel A; Duerksen, Donald R

2017-09-01

Tests to measure serum endomysial antibodies (EMA) and antibodies to tissue transglutaminase (tTG) were developed to screen for celiac disease in patients consuming gluten. However, they are commonly used to monitor patients on a gluten-free diet (GFD). We conducted a meta-analysis to assess the sensitivity and specificity of tTG IgA and EMA IgA assays in identifying patients with celiac disease who have persistent villous atrophy despite a GFD. We searched PUBMED, EMBASE, BIOSIS, SCOPUS, clinicaltrials.gov, Science Citation Index, and Cochrane Library databases through November 2016. Inclusion criteria were studies of subjects with biopsy-confirmed celiac disease, follow-up biopsies, and measurement of serum antibodies on a GFD, biopsy performed on subjects regardless of symptoms, or antibody test results. Our analysis excluded subjects with refractory celiac disease, undergoing gluten challenge, or consuming a prescribed oats-containing GFD. Tests were considered to have positive or negative findings based on manufacturer cut-off values. Villous atrophy was defined as a Marsh 3 lesion or villous height:crypt depth ratio below 3.0. We constructed forest plots to determine the sensitivity and specificity of detection for individual studies. For the meta-analysis, a bivariate random effects model was used to jointly model sensitivity and specificity. Our search identified 5408 unique citations. Following review of abstracts, 442 articles were reviewed in detail. Only 26 studies (6 of tTG assays, 15 of EMA assays, and 5 of tTG and EMA assays) met our inclusion criteria. The most common reason studies were excluded from our analysis was inability to cross-tabulate histologic and serologic findings. The serum assays identified patients with persistent villous atrophy with high levels of specificity: 0.83 for the tTG IgA assay (95% CI, 0.79-0.87) and 0.91 for the EMA IgA assay (95% CI, 0.87-0.94). However, they detected villous atrophy with low levels of sensitivity: 0.50 for the tTG IgA assay (95% CI, 0.41-0.60) and 0.45 for the EMA IgA assay (95% CI, 0.34-0.57). The tests had similar levels of performance in pediatric and adult patients. In a meta-analysis of patients with biopsy-confirmed celiac disease undergoing follow-up biopsy on a GFD, we found that tests for serum tTG IgA and EMA IgA levels had low sensitivity (below 50%) in detection of persistent villous atrophy. We need more-accurate non-invasive markers of mucosal damage in children and adults with celiac disease who are following a GFD. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

The CD63 basophil activation test in Hymenoptera venom allergy: a prospective study.

PubMed

Sturm, G J; Böhm, E; Trummer, M; Weiglhofer, I; Heinemann, A; Aberer, W

2004-10-01

The basophil activation test (BAT), which relies on flow cytometric quantitation of the allergen-induced up-regulation of the granule-associated marker CD63 in peripheral blood basophils, has been suggested to be a useful approach in detecting responsiveness to allergens. The purpose of this study was to establish the usefulness of the BAT with regard to the clinical history and current diagnostic tools in Hymenoptera venom allergy using a prospective study design. Fifty-seven consecutive patients allergic to Hymenoptera venom as defined by a systemic reaction after an insect sting, and 30 age- and sex-matched control subjects with a negative history were included. The degree and nature of sensitization was confirmed by skin testing, specific immunoglobulin E (IgE), serum tryptase levels and BAT. In the nonallergic control group only analysis of specific IgE and BAT were performed. Correlation of BAT, skin test and specific IgE, respectively, with the clinical history in the allergic group was termed as sensitivity and in the control group as specificity. Twenty one of 23 (91.3%) bee venom allergic patients and 29 of 34 (85.3%) patients allergic to wasp and hornet venom tested positive in BAT. The overall sensitivity of BAT, specific IgE and skin tests were 87.7, 91.2 and 93.0%, respectively. The overall specificities were 86.7% for BAT and 66.7% for specific IgE. No correlation between the severity of clinical symptoms and the magnitude of basophil activation was observed. The BAT seems to be an appropriate method to identify patients allergic to bee or wasp venom with a comparable sensitivity to standard diagnostic regimens. The higher specificity of BAT as compared with specific IgE makes this test a useful tool in the diagnosis of Hymenoptera venom allergy.

Performance of Ultrasound in the Diagnosis of Gout in a Multicenter Study: Comparison With Monosodium Urate Monohydrate Crystal Analysis as the Gold Standard.

PubMed

Ogdie, Alexis; Taylor, William J; Neogi, Tuhina; Fransen, Jaap; Jansen, Tim L; Schumacher, H Ralph; Louthrenoo, Worawit; Vazquez-Mellado, Janitzia; Eliseev, Maxim; McCarthy, Geraldine; Stamp, Lisa K; Perez-Ruiz, Fernando; Sivera, Francisca; Ea, Hang-Korng; Gerritsen, Martijn; Cagnotto, Giovanni; Cavagna, Lorenzo; Lin, Chingtsai; Chou, Yin-Yi; Tausche, Anne-Kathrin; Lima Gomes Ochtrop, Manuella; Janssen, Matthijs; Chen, Jiunn-Horng; Slot, Ole; Lazovskis, Juris; White, Douglas; Cimmino, Marco A; Uhlig, Till; Dalbeth, Nicola

2017-02-01

To examine the performance of ultrasound (US) for the diagnosis of gout using the presence of monosodium urate monohydrate (MSU) crystals as the gold standard. We analyzed data from the Study for Updated Gout Classification Criteria (SUGAR), a large, multicenter observational cross-sectional study of consecutive subjects with at least 1 swollen joint who conceivably may have gout. All subjects underwent arthrocentesis; cases were subjects with confirmed MSU crystals. Rheumatologists or radiologists who were blinded with regard to the results of the MSU crystal analysis performed US on 1 or more clinically affected joints. US findings of interest were double contour sign, tophus, and snowstorm appearance. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Multivariable logistic regression models were used to examine factors associated with positive US results among subjects with gout. US was performed in 824 subjects (416 cases and 408 controls). The sensitivity, specificity, PPV, and NPV for the presence of any 1 of the features were 76.9%, 84.3%, 83.3%, and 78.2%, respectively. Sensitivity was higher among subjects with a disease duration of ≥2 years and among subjects with subcutaneous nodules on examination (suspected tophus). Associations with a positive US finding included suspected clinical tophus (odds ratio [OR] 4.77 [95% confidence interval (95% CI) 2.23-10.21]), any abnormality on plain radiography (OR 4.68 [95% CI 2.68-8.17]), and serum urate level (OR 1.31 [95% CI 1.06-1.62]). US features of MSU crystal deposition had high specificity and high PPV but more limited sensitivity for early gout. The specificity remained high in subjects with early disease and without clinical signs of tophi. © 2016, American College of Rheumatology.

Classifying post-stroke fatigue: Optimal cut-off on the Fatigue Assessment Scale.

PubMed

Cumming, Toby B; Mead, Gillian

2017-12-01

Post-stroke fatigue is common and has debilitating effects on independence and quality of life. The Fatigue Assessment Scale (FAS) is a valid screening tool for fatigue after stroke, but there is no established cut-off. We sought to identify the optimal cut-off for classifying post-stroke fatigue on the FAS. In retrospective analysis of two independent datasets (the '2015' and '2007' studies), we evaluated the predictive validity of FAS score against a case definition of fatigue (the criterion standard). Area under the curve (AUC) and sensitivity and specificity at the optimal cut-off were established in the larger 2015 dataset (n=126), and then independently validated in the 2007 dataset (n=52). In the 2015 dataset, AUC was 0.78 (95% CI 0.70-0.86), with the optimal ≥24 cut-off giving a sensitivity of 0.82 and specificity of 0.66. The 2007 dataset had an AUC of 0.83 (95% CI 0.71-0.94), and applying the ≥24 cut-off gave a sensitivity of 0.84 and specificity of 0.67. Post-hoc analysis of the 2015 dataset revealed that using only the 3 most predictive FAS items together ('FAS-3') also yielded good validity: AUC 0.81 (95% CI 0.73-0.89), with sensitivity of 0.83 and specificity of 0.75 at the optimal ≥8 cut-off. We propose ≥24 as a cut-off for classifying post-stroke fatigue on the FAS. While further validation work is needed, this is a positive step towards a coherent approach to reporting fatigue prevalence using the FAS. Copyright © 2017 Elsevier Inc. All rights reserved.

Diagnostic performance of short portable mental status questionnaire for screening dementia among patients attending cognitive assessment clinics in Singapore.

PubMed

Malhotra, Chetna; Chan, Angelique; Matchar, David; Seow, Dennis; Chuo, Adeline; Do, Young Kyung

2013-07-01

The Short Portable Mental Status Questionnaire (SPMSQ) is a brief cognitive screening instrument, which is easy to use by a healthcare worker with little training. However, the validity of this instrument has not been established in Singapore. Thus, the primary aim of this study was to determine the diagnostic performance of SPMSQ for screening dementia among patients attending outpatient cognitive assessment clinics and to assess whether the appropriate cut-off score varies by patient's age and education. A secondary aim of the study was to map the SPMSQ scores with Mini-Mental State Examination (MMSE) scores. SPMSQ and MMSE were administered by a trained interviewer to 127 patients visiting outpatient cognitive assessment clinics at the Singapore General Hospital, Changi General Hospital and Tan Tock Seng Hospital. The geriatricians at these clinics then diagnosed these patients with dementia or no dementia (reference standard). Sensitivity and specificity of SPMSQ with different cut-off points (number of errors) were calculated and compared to the reference standard using the Receiver Operator Characteristic (ROC) analysis. Correlation coefficient was also calculated between MMSE and SPMSQ scores. Based on the ROC analysis and a balance of sensitivity and specificity, the appropriate cut-off for SPMSQ was found to be 5 or more errors (sensitivity 78%, specificity 75%). The cut-off varied by education, but not by patient's age. There was a high correlation between SPMSQ and MMSE scores (r = 0.814, P <0.0001). Despite the advantage of being a brief screening instrument for dementia, the use of SPMSQ is limited by its low sensitivity and specificity, especially among patients with less than 6 years of education.

Sensitivity and specificity of a hand-held milk electrical conductivity meter compared to the California mastitis test for mastitis in dairy cattle.

PubMed

Fosgate, G T; Petzer, I M; Karzis, J

2013-04-01

Screening tests for mastitis can play an important role in proactive mastitis control programs. The primary objective of this study was to compare the sensitivity and specificity of milk electrical conductivity (EC) to the California mastitis test (CMT) in commercial dairy cattle in South Africa using Bayesian methods without a perfect reference test. A total of 1848 quarter milk specimens were collected from 173 cows sampled during six sequential farm visits. Of these samples, 25.8% yielded pathogenic bacterial isolates. The most frequently isolated species were coagulase negative Staphylococci (n=346), Streptococcus agalactiae (n=54), and Staphylococcus aureus (n=42). The overall cow-level prevalence of mastitis was 54% based on the Bayesian latent class (BLC) analysis. The CMT was more accurate than EC for classification of cows having somatic cell counts >200,000/mL and for isolation of a bacterial pathogen. BLC analysis also suggested an overall benefit of CMT over EC but the statistical evidence was not strong (P=0.257). The Bayesian model estimated the sensitivity and specificity of EC (measured via resistance) at a cut-point of >25 mΩ/cm to be 89.9% and 86.8%, respectively. The CMT had a sensitivity and specificity of 94.5% and 77.7%, respectively, when evaluated at the weak positive cut-point. EC was useful for identifying milk specimens harbouring pathogens but was not able to differentiate among evaluated bacterial isolates. Screening tests can be used to improve udder health as part of a proactive management plan. Copyright © 2012 Elsevier Ltd. All rights reserved.

Performance of Ultrasound in the Diagnosis of Gout in a Multi-Center Study: Comparison with Monosodium Urate Crystal Analysis as the Gold Standard

PubMed Central

Ogdie, Alexis; Taylor, William J; Neogi, Tuhina; Fransen, Jaap; Jansen, Tim L; Schumacher, H. Ralph; Louthrenoo, Worawit; Vazquez-Mellado, Janitzia; Eliseev, Maxim; McCarthy, Geraldine; Stamp, Lisa K.; Perez-Ruiz, Fernando; Sivera, Francisca; Ea, Hang-Korng; Gerritsen, Martijn; Cagnotto, Giovanni; Cavagna, Lorenzo; Lin, Chingtsai; Chou, Yin-Yi; Tausche, Anne-Kathrin; Ochtrop, Manuella Lima Gomes; Janssen, Matthijs; Chen, Jiunn-Horng; Slot, Ole; Lazovskis, Juris; White, Douglas; Cimmino, Marco A.; Uhlig, Till; Dalbeth, Nicola

2017-01-01

Objectives To examine the performance of ultrasound for the diagnosis of gout using presence of monosodium urate (MSU) crystals as the gold standard. Methods We analyzed data from the Study for Updated Gout Classification Criteria (SUGAR), a large, multi-center observational cross-sectional study of consecutive subjects with at least one swollen joint who conceivably may have gout. All subjects underwent arthrocentesis; cases were subjects with MSU crystal confirmation. Rheumatologists or radiologists, blinded to the results of the MSU crystal analysis, performed ultrasound on one or more clinically affected joints. Ultrasound findings of interest were: double contour sign (DCS), tophus, and ‘snowstorm’ appearance. Sensitivity, specificity, positive and negative predictive values (PPV and NPV) were calculated. Multivariable logistic regression models were used to examine factors associated with positive ultrasound results among subjects with gout. Results Ultrasound was performed in 824 subjects (416 cases and 408 controls). The sensitivity, specificity, PPV and NPV for the presence of any one of the features were 76.9%, 84.3%, 83.3% and 78.1% respectively. Sensitivity was higher among subjects with disease ≥2 years duration and among subjects with subcutaneous nodules on exam (suspected tophus). Associations with a positive ultrasound finding included suspected clinical tophus (odds ratio 4.77; 95% CI 2.23–10.21), any abnormal plain film radiograph (4.68; 2.68–8.17) and serum urate (1.31; 1.06–1.62). Conclusions Ultrasound features of MSU crystal deposition had high specificity and high positive predictive value but more limited sensitivity for early gout. The specificity remained high in subjects with early disease and without clinical signs of tophi. PMID:27748084

Comparison of Abbott RealTime High-Risk HPV and Hybrid Capture 2 Assays for Detection of HPV Infection.

PubMed

Ko, Kiwoong; Yu, Shinae; Lee, Eun Hee; Park, Hyosoon; Woo, Hee-Yeon; Kwon, Min-Jung

2016-09-01

Various assays for detecting high-risk human papillomavirus (HR HPV) have been introduced recently, including the Abbott RealTime High-Risk HPV assay. We sought to compare the performance of Abbott PCR to Hybrid Capture 2 for the detection of HR HPV. A total of 941 cervical swab specimens were obtained. We submitted all specimens for HR HPV detection with HC2 and Abbott PCR, and then additionally analyzed discordant and concordant positive results using restriction fragment mass polymorphism (RFMP) genotyping analysis. HC2 detected one of 13 HR HPV types in 12.3% (116/941) of cases, while Abbott PCR detected one of 14 detectable HR HPV types in 12.9% (121/941) of cases. The overall agreement rate was 97.3% with a kappa coefficient of 0.879. Discordant results between these two assays were observed in 25 cases. HC2 showed a sensitivity of 90.0% and specificity of 95.9%, while Abbott PCR showed a sensitivity of 98.0% and specificity of 96.8% when using RFMP results as the gold standard. For HPV 16/18 detection, Abbott PCR showed 95.8%/88.9% sensitivity and 99.2%/99.8% specificity, respectively. The overall coinfection rate between HPV 16, 18 and non-16/18 was 9.9% (12/121) in Abbott PCR analysis. Considering its high agreement rate with HC2, higher sensitivity/specificity compared to HC2, and ability to differentiate HPV 16/18 from other HPV types, Abbott PCR could be a reliable laboratory testing method for the screening of HPV infections. © 2016 by the Association of Clinical Scientists, Inc.

Accuracy of software-assisted detection of tumour feeders in transcatheter hepatic chemoembolization using three target definition protocols.

PubMed

Iwazawa, J; Ohue, S; Hashimoto, N; Mitani, T

2014-02-01

To compare the accuracy of computer software analysis using three different target-definition protocols to detect tumour feeder vessels for transarterial chemoembolization of hepatocellular carcinoma. C-arm computed tomography (CT) data were analysed for 81 tumours from 57 patients who had undergone chemoembolization using software-assisted detection of tumour feeders. Small, medium, and large-sized targets were manually defined for each tumour. The tumour feeder was verified when the target tumour was enhanced on selective C-arm CT of the investigated vessel during chemoembolization. The sensitivity, specificity, and accuracy of the three protocols were evaluated and compared. One hundred and eight feeder vessels supplying 81 lesions were detected. The sensitivity of the small, medium, and large target protocols was 79.8%, 91.7%, and 96.3%, respectively; specificity was 95%, 88%, and 50%, respectively; and accuracy was 87.5%, 89.9%, and 74%, respectively. The sensitivity was significantly higher for the medium (p = 0.003) and large (p < 0.001) target protocols than for the small target protocol. The specificity and accuracy were higher for the small (p < 0.001 and p < 0.001, respectively) and medium (p < 0.001 and p < 0.001, respectively) target protocols than for the large target protocol. The overall accuracy of software-assisted automated feeder analysis in transarterial chemoembolization for hepatocellular carcinoma is affected by the target definition size. A large target definition increases sensitivity and decreases specificity in detecting tumour feeders. A target size equivalent to the tumour size most accurately predicts tumour feeders. Copyright © 2013 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Quantitative Shear Wave Velocity Measurement on Acoustic Radiation Force Impulse Elastography for Differential Diagnosis between Benign and Malignant Thyroid Nodules: A Meta-analysis.

PubMed

Liu, Bo-Ji; Li, Dan-Dan; Xu, Hui-Xiong; Guo, Le-Hang; Zhang, Yi-Feng; Xu, Jun-Mei; Liu, Chang; Liu, Lin-Na; Li, Xiao-Long; Xu, Xiao-Hong; Qu, Shen; Xing, Mingzhao

2015-12-01

The aim of this study was to evaluate the diagnostic performance of quantitative shear wave velocity (SWV) measurement on acoustic radiation force impulse (ARFI) elastography for differentiation between benign and malignant thyroid nodules using meta-analysis. The databases of PubMed and the Web of Science were searched. Studies published in English on assessment of the sensitivity and specificity of ARFI elastography for the differentiation of thyroid nodules were collected. The quantitative measurement of ARFI elastography was evaluated by SWV (m/s). Meta-Disc Version 1.4 software was used to describe and calculate the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio and summary receiver operating characteristic curves. We analyzed a total of 13 studies, which included 1,854 thyroid nodules (including 1,339 benign nodules and 515 malignant nodules) from 1,641 patients. The summary sensitivity and specificity for differential diagnosis between benign and malignant thyroid nodules by SWV were 0.81 (95% confidence interval [CI]: 0.77-0.84) and 0.84 (95% CI: 0.81-0.86), respectively. The pooled positive and negative likelihood ratios were 5.21 (95% CI: 3.56-7.62) and 0.23 (95% CI: 0.17-0.32), respectively. The pooled diagnostic odds ratio was 27.53 (95% CI: 14.58-52.01), and the area under the summary receiver operating characteristic curve was 0.91 (Q* = 0.84). In conclusion, SWV measurement on ARFI elastography has high sensitivity and specificity for differential diagnosis between benign and malignant thyroid nodules and can be used in combination with conventional ultrasound. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

The diagnostic test accuracy of magnetic resonance imaging, magnetic resonance arthrography and computer tomography in the detection of chondral lesions of the hip.

PubMed

Smith, Toby O; Simpson, Michael; Ejindu, Vivian; Hing, Caroline B

2013-04-01

The purpose of this study was to assess the diagnostic test accuracy of magnetic resonance imaging (MRI), magnetic resonance arthrography (MRA) and multidetector arrays in CT arthrography (MDCT) for assessing chondral lesions in the hip joint. A review of the published and unpublished literature databases was performed to identify all studies reporting the diagnostic test accuracy (sensitivity/specificity) of MRI, MRA or MDCT for the assessment of adults with chondral (cartilage) lesions of the hip with surgical comparison (arthroscopic or open) as the reference test. All included studies were reviewed using the quality assessment of diagnostic accuracy studies appraisal tool. Pooled sensitivity, specificity, likelihood ratios and diagnostic odds ratios were calculated with 95 % confidence intervals using a random-effects meta-analysis for MRI, MRA and MDCT imaging. Eighteen studies satisfied the eligibility criteria. These included 648 hips from 637 patients. MRI indicated a pooled sensitivity of 0.59 (95 % CI: 0.49-0.70) and specificity of 0.94 (95 % CI: 0.90-0.97), and MRA sensitivity and specificity values were 0.62 (95 % CI: 0.57-0.66) and 0.86 (95 % CI: 0.83-0.89), respectively. The diagnostic test accuracy for the detection of hip joint cartilage lesions is currently superior for MRI compared with MRA. There were insufficient data to perform meta-analysis for MDCT or CTA protocols. Based on the current limited diagnostic test accuracy of the use of magnetic resonance or CT, arthroscopy remains the most accurate method of assessing chondral lesions in the hip joint.

Apparent diffusion coefficient on magnetic resonance imaging (MRI) in bladder cancer: relations with recurrence/progression risk

PubMed Central

Kikuchi, Ken; Shigihara, Takeshi; Hashimoto, Yuko; Miyajima, Masayuki; Haga, Nobuhiro; Kojima, Yoshiyuki; Shishido, Fumio

2017-01-01

Abstract AIMS: To evaluate the relationship between the apparent diffusion coefficient (ADC) value for bladder cancer and the recurrence/progression risk of post-transurethral resection (TUR). METHODS: Forty-one patients with initial and non-muscle-invasive bladder cancer underwent MRI from 2009 to 2012. Two radiologists measured ADC values. A pathologist calculated the recurrence/progression scores, and risk was classified based on the scores. Pearson’s correlation was used to analyze the correlations of ADC value with each score and with each risk group, and the optimal cut-off value was established based on receiver operating characteristic (ROC) curve analysis. Furthermore, the relationship between actual recurrence / progression of cases and ADC values was examined by Unpaird U test. RESULTS: There were significant correlations between ADC value and the recurrence score as well as the progression score (P<0.01, P<0.01, respectively). There were also significant correlations between ADC value and the recurrence risk group as well as progression risk group (P=0.042, P<0.01, respectively). The ADC cut-off value on ROC analysis was 1.365 (sensitivity 100%; specificity 97.4%) for the low and intermediate recurrence risk groups, 1.024 (sensitivity 47.4%; specificity 100%) for the intermediate and high recurrence risk groups, 1.252 (sensitivity 83.3%; specificity 81.3%) for the low and intermediate progression risk groups, and 0.955 (sensitivity 87.5%; specificity 63.2%) between the intermediate and high progression risk groups. The difference between the ADC values of the recurrence and nonrecurrence group in Unpaired t test was significant (P<0.05). CONCLUSION: ADC on MRI in bladder cancer could potentially be useful, non-invasive measurement for estimating the risks of recurrence and progression. PMID:28680010

Accuracy of early detection of colorectal tumours by stool methylation markers: A meta-analysis

PubMed Central

Zhang, Hu; Qi, Jian; Wu, Ya-Qiong; Zhang, Ping; Jiang, Jun; Wang, Qi-Xian; Zhu, You-Qing

2014-01-01

AIM: To evaluate the accuracy of methylation of genes in stool samples for diagnosing colorectal tumours. METHODS: Electronic databases including PubMed, Web of Science, Chinese Journals Full-Text Database and Wanfang Journals Full-Text Database were searched to find relevant original articles about methylated genes to be used in diagnosing colorectal tumours. A quality assessment of diagnostic accuracy studies tool (QADAS) was used to evaluate the quality of the included articles, and the Meta-disc 1.4 and SPSS 13.0 software programs were used for data analysis. RESULTS: Thirty-seven articles met the inclusion criteria, and 4484 patients were included. The sensitivity and specificity for the detection of colorectal cancer (CRC) were 73% (95%CI: 71%-75%) and 92% (95%CI: 90%-93%), respectively. For adenoma, the sensitivity and specificity were 51% (95%CI: 47%-54%) and 92% (95%CI: 90%-93%), respectively. Pooled diagnostic performance of SFRP2 methylation for CRC provided the following results: the sensitivity was 79% (95%CI: 75%-82%), the specificity was 93% (95%CI: 90%-96%), the diagnostic OR was 47.57 (95%CI: 20.08-112.72), the area under the curve was 0.9565. Additionally, the results of accuracy of SFRP2 methylation for detecting colorectal adenomas were as follows: sensitivity was 43% (95%CI: 38%-49%), specificity was 94% (95%CI: 91%-97%), the diagnostic OR was 11.06 (95%CI: 5.77-21.18), and the area under the curve was 0.9563. CONCLUSION: Stool-based DNA testing may be useful for noninvasively diagnosing colorectal tumours and SFRP2 methylation is a promising marker that has great potential in early CRC diagnosis. PMID:25320544

The utility of a classificatory decision tree approach to assist clinical differentiation of melancholic and non-melancholic depression.

PubMed

Parker, G; McCraw, S; Hadzi-Pavlovic, D

2015-07-15

Studies suggest that differentiating melancholic from non-melancholic depressive disorders is advanced by use of illness course as well as symptom variables but, in practice, potentially differentiating variables are generally positioned as having equal value. Judging that differentiating features are more likely to vary in their signal intensity, we sought to determine the number of features required to effect differentiation and their hierarchical order. The 24-item clinician-rated Sydney Melancholia Prototype Index (SMPI-CR) was completed for 364 unipolar depressed patients. The sample was divided into two cohorts according to the recruitment period. An RPART classification tree analysis identified the most discriminating SMPI items in the development sample of 197 patients, and examined the sensitivity and specificity of the diagnostic decisions, then sought to replicate findings in a validation sample of 169 patients. Independent analyses of putative SMPI items identified only seven items as required to discriminate those with clinically-diagnosed melancholic or non-melancholic depression when the conditions were examined separately. An RPART analysis considering differentiation of melancholic and non-melancholic depression in the total samples retained five of those items in the classification tree, three of which were non-symptom items, and with 92% sensitivity and 80% specificity in the development sample. This reduced item set showed 93% sensitivity and 82% specificity in the validation sample. Our clinical judgment of melancholic or non-melancholic depression may not correspond with the clinical logic employed by other clinicians. Only five SMPI items were required to derive a succinct and efficient decision tree, comprising high sensitivity and specificity in differentiating melancholic and non-melancholic depression. Current study findings provide an empirical model that could enrich clinicians׳ approach to differentiating melancholic and non-melancholic depression. Copyright © 2015 Elsevier B.V. All rights reserved.

Diagnostic algorithm for detection of targetable driver mutations in lung adenocarcinomas: Comprehensive analyses of 205 cases with immunohistochemistry, real-time PCR and fluorescence in situ hybridization methods.

PubMed

Kao, Hua-Lin; Yeh, Yi-Chen; Lin, Chin-Hsuan; Hsu, Wei-Fang; Hsieh, Wen-Yu; Ho, Hsiang-Ling; Chou, Teh-Ying

2016-11-01

Analysis of the targetable driver mutations is now recommended in all patients with advanced lung adenocarcinoma. Molecular-based methods are usually adopted, however, along with the implementation of highly sensitive and/or mutation-specific antibodies, immunohistochemistry (IHC) has been considered an alternative method for identifying driver mutations in lung adenocarcinomas. A total of 205 lung adenocarcinomas were examined for EGFR mutations and ALK and ROS1 rearrangements using real-time PCR, fluorescence in situ hybridization (FISH) and IHC in parallel. The performance of different commercially available IHC antibody clones toward targetable driver mutations was evaluated. The association between these driver mutations and clinicopathological characteristics was also analyzed. In 205 cases we studied, 58.5% were found to harbor EGFR mutations, 6.3% ALK rearrangements and 1.0% ROS1 rearrangements. Compared to molecular-based methods, IHC of EGFR mutations showed an excellent specificity but the sensitivity is suboptimal, while IHC of ALK and ROS1 rearrangements demonstrated high sensitivity and specificity. No significant difference regarding the performance of different antibody clones toward these driver mutations was observed, except that clone SP125 showed a higher sensitivity than 43B2 in the detection of p.L858R of EGFR. In circumstances such as poor quality of nucleic acids or low content of tumor cells, IHC of EGFR mutation-specific antibodies could be used as an alternative method. Patients negative for EGFR mutations are subjected to further analysis on ALK and ROS1 rearrangements using IHC methods. Herein, we proposed a lung adenocarcinoma testing algorithm for the application of IHC in therapeutic diagnosis. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Accuracy of early detection of colorectal tumours by stool methylation markers: a meta-analysis.

PubMed

Zhang, Hu; Qi, Jian; Wu, Ya-Qiong; Zhang, Ping; Jiang, Jun; Wang, Qi-Xian; Zhu, You-Qing

2014-10-14

To evaluate the accuracy of methylation of genes in stool samples for diagnosing colorectal tumours. Electronic databases including PubMed, Web of Science, Chinese Journals Full-Text Database and Wanfang Journals Full-Text Database were searched to find relevant original articles about methylated genes to be used in diagnosing colorectal tumours. A quality assessment of diagnostic accuracy studies tool (QADAS) was used to evaluate the quality of the included articles, and the Meta-disc 1.4 and SPSS 13.0 software programs were used for data analysis. Thirty-seven articles met the inclusion criteria, and 4484 patients were included. The sensitivity and specificity for the detection of colorectal cancer (CRC) were 73% (95%CI: 71%-75%) and 92% (95%CI: 90%-93%), respectively. For adenoma, the sensitivity and specificity were 51% (95%CI: 47%-54%) and 92% (95%CI: 90%-93%), respectively. Pooled diagnostic performance of SFRP2 methylation for CRC provided the following results: the sensitivity was 79% (95%CI: 75%-82%), the specificity was 93% (95%CI: 90%-96%), the diagnostic OR was 47.57 (95%CI: 20.08-112.72), the area under the curve was 0.9565. Additionally, the results of accuracy of SFRP2 methylation for detecting colorectal adenomas were as follows: sensitivity was 43% (95%CI: 38%-49%), specificity was 94% (95%CI: 91%-97%), the diagnostic OR was 11.06 (95%CI: 5.77-21.18), and the area under the curve was 0.9563. Stool-based DNA testing may be useful for noninvasively diagnosing colorectal tumours and SFRP2 methylation is a promising marker that has great potential in early CRC diagnosis.

The Accuracy of Integrated [18F] Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography in Detection of Pelvic and Para-aortic Nodal Metastasis in Patients with High Risk Endometrial Cancer

PubMed Central

Gholkar, Nikhil Shirish; Saha, Subhas Chandra; Prasad, GRV; Bhattacharya, Anish; Srinivasan, Radhika; Suri, Vanita

2014-01-01

Lymph nodal (LN) metastasis is the most important prognostic factor in high-risk endometrial cancer. However, the benefit of routine lymphadenectomy in endometrial cancer is controversial. This study was conducted to assess the accuracy of [18F] fluorodeoxyglucose-positron emission tomography/computed tomography ([18F] FDG-PET/CT) in detection of pelvic and para-aortic nodal metastases in high-risk endometrial cancer. 20 patients with high-risk endometrial carcinoma underwent [18F] FDG-PET/CT followed by total abdominal hysterectomy, bilateral salpingo-oophorectomy and systematic pelvic lymphadenectomy with or without para-aortic lymphadenectomy. The findings on histopathology were compared with [18F] FDG-PET/CT findings to calculate the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of [18F] FDG-PET/CT. The pelvic nodal findings were analyzed on a patient and nodal chain based criteria. The para-aortic nodal findings were reported separately. Histopathology documented nodal involvement in two patients (10%). For detection of pelvic nodes, on a patient based analysis, [18F] FDG-PET/CT had a sensitivity of 100%, specificity of 61.11%, PPV of 22.22%, NPV of 100% and accuracy of 65% and on a nodal chain based analysis, [18F] FDG-PET/CT had a sensitivity of 100%, specificity of 80%, PPV of 20%, NPV of 100%, and accuracy of 80.95%. For detection of para-aortic nodes, [18F] FDG-PET/CT had sensitivity of 100%, specificity of 66.67%, PPV of 20%, NPV of 100%, and accuracy of 69.23%. Although [18F] FDG-PET/CT has high sensitivity for detection of LN metastasis in endometrial carcinoma, it had moderate accuracy and high false positivity. However, the high NPV is important in selecting patients in whom lymphadenectomy may be omitted. PMID:25538488

Spectrophotometry or visual inspection to most reliably detect xanthochromia in subarachnoid hemorrhage: systematic review.

PubMed

Chu, Kevin; Hann, Angus; Greenslade, Jaimi; Williams, Julian; Brown, Anthony

2014-09-01

We assess the sensitivity and specificity of xanthochromia as adjudicated by visual inspection and spectrophotometry at predicting the presence of cerebral aneurysm in patients with suspected subarachnoid hemorrhage who have a normal computed tomography (CT) head scan result. A systematic review was performed. MEDLINE and EMBASE databases were searched. Relevant studies with clinical data on the diagnostic accuracy of visual inspection or spectrophotometry were considered. Patients who had a normal CT head scan result followed by a lumbar puncture were included in this review. Sensitivities, specificities, and heterogeneity (I(2)) were calculated. Subgroup analyses were performed to explore reasons for the heterogeneity. There were major methodological limitations in the studies found. Twenty-two relevant articles were heterogeneous in regard to time to lumbar puncture, spectrophotometry methods, and follow-up of patients not undergoing cerebral angiography. Twelve of the 22 studies selected patients on the basis of a cerebral aneurysm or subarachnoid hemorrhage on imaging, or a positive lumbar puncture result. These studies were excluded from our initial analysis, which included only patients with clinically suspected subarachnoid hemorrhage. In this initial analysis, pooled estimates of sensitivity and specificity for spectrophotometry were 87% (95% confidence interval [CI] 71% to 96%; I(2)=26%) and 86% (95% CI 84% to 88%; I(2)=96%), respectively. For visual inspection, pooled sensitivity and specificity were 83% (95% CI 59% to 96%; I(2)=52%) and 96% (95% CI 93% to 97%; I(2)=76%), respectively. Sensitivity estimates are difficult to interpret without knowing time to lumbar puncture. The heterogeneity in the underlying studies, combined with significant overlap in pooled confidence limits, makes it impossible to provide a definite conclusion about the diagnostic accuracy of spectrophotometry versus visual inspection. Copyright © 2014 American College of Emergency Physicians. Published by Mosby, Inc. All rights reserved.

Proteomic biomarkers apolipoprotein A1, truncated transthyretin and connective tissue activating protein III enhance the sensitivity of CA125 for detecting early stage epithelial ovarian cancer.

PubMed

Clarke, Charlotte H; Yip, Christine; Badgwell, Donna; Fung, Eric T; Coombes, Kevin R; Zhang, Zhen; Lu, Karen H; Bast, Robert C

2011-09-01

The low prevalence of ovarian cancer demands both high sensitivity (>75%) and specificity (99.6%) to achieve a positive predictive value of 10% for successful early detection. Utilizing a two stage strategy where serum marker(s) prompt the performance of transvaginal sonography (TVS) in a limited number (2%) of women could reduce the requisite specificity for serum markers to 98%. We have attempted to improve sensitivity by combining CA125 with proteomic markers. Sera from 41 patients with early stage (I/II) and 51 with late stage (III/IV) epithelial ovarian cancer, 40 with benign disease and 99 healthy individuals, were analyzed to measure 7 proteins [Apolipoprotein A1 (Apo-A1), truncated transthyretin (TT), transferrin, hepcidin, ß-2-microglobulin (ß2M), Connective Tissue Activating Protein III (CTAPIII), and Inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4)]. Statistical models were fit by logistic regression, followed by optimization of factors retained in the models determined by optimizing the Akaike Information Criterion. A validation set included 136 stage I ovarian cancers, 140 benign pelvic masses and 174 healthy controls. In a training set analysis, the 3 most effective biomarkers (Apo-A1, TT and CTAPIII) exhibited 54% sensitivity at 98% specificity, CA125 alone produced 68% sensitivity and the combination increased sensitivity to 88%. In a validation set, the marker panel plus CA125 produced a sensitivity of 84% at 98% specificity (P=0.015, McNemar's test). Combining a panel of proteomic markers with CA125 could provide a first step in a sequential two-stage strategy with TVS for early detection of ovarian cancer. Copyright © 2011. Published by Elsevier Inc.

Proteomic Biomarkers Apolipoprotein A1, Truncated Transthyretin and Connective Tissue Activating Protein III Enhance the Sensitivity of CA125 for Detecting Early Stage Epithelial Ovarian Cancer

PubMed Central

Clarke, Charlotte H.; Yip, Christine; Badgwell, Donna; Fung, Eric T.; Coombes, Kevin R.; Zhang, Zhen; Lu, Karen H.; Bast, Robert C.

2011-01-01

Objective The low prevalence of ovarian cancer demands both high sensitivity (>75%) and specificity (99.6%) to achieve a positive predictive value of 10% for successful early detection. Utilizing a two stage strategy where serum marker(s) prompt the performance of transvaginal sonography (TVS) in a limited number (2%) of women could reduce the requisite specificity for serum markers to 98%. We have attempted to improve sensitivity by combining CA125 with proteomic markers. Methods Sera from 41 patients with early stage (I/II) and 51 with late stage (III/IV) epithelial ovarian cancer, 40 with benign disease and 99 healthy individuals, were analyzed to measure 7 proteins [Apolipoprotein A1 (Apo-A1), truncated transthyretin (TT), transferrin, hepcidin, ß-2-microglobulin (ß2M), Connective Tissue Activating Protein III (CTAPIII), and Inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4)]. Statistical models were fit by logistic regression, followed by optimization of factors retained in the models determined by optimizing the Akaike Information Criterion. A validation set included 136 stage I ovarian cancers, 140 benign pelvic masses and 174 healthy controls. Results In a training set analysis, the 3 most effective biomarkers (Apo-A1, TT and CTAPIII) exhibited 54% sensitivity at 98% specificity, CA125 alone produced 68% sensitivity and the combination increased sensitivity to 88%. In a validation set, the marker panel plus CA125 produced a sensitivity of 84% at 98% specificity (P= 0.015, McNemar's test). Conclusion Combining a panel of proteomic markers with CA125 could provide a first step in a sequential two-stage strategy with TVS for early detection of ovarian cancer. PMID:21708402

Characterization and Comparison of Galactomannan Enzyme Immunoassay and Quantitative Real-Time PCR Assay for Detection of Aspergillus fumigatus in Bronchoalveolar Lavage Fluid from Experimental Invasive Pulmonary Aspergillosis

PubMed Central

Francesconi, Andrea; Kasai, Miki; Petraitiene, Ruta; Petraitis, Vidmantas; Kelaher, Amy M.; Schaufele, Robert; Hope, William W.; Shea, Yvonne R.; Bacher, John; Walsh, Thomas J.

2006-01-01

Bronchoalveolar lavage (BAL) is widely used for evaluation of patients with suspected invasive pulmonary aspergillosis (IPA). However, the diagnostic yield of BAL for detection of IPA by culture and direct examination is limited. Earlier diagnosis may be facilitated by assays that can detect Aspergillus galactomannan antigen or DNA in BAL fluid. We therefore characterized and compared the diagnostic yields of a galactomannan enzyme immunoassay (GM EIA), quantitative real-time PCR (qPCR), and quantitative cultures in experiments using BAL fluid from neutropenic rabbits with experimentally induced IPA defined as microbiologically and histologically evident invasion. The qPCR assay targeted the rRNA gene complex of Aspergillus fumigatus. The GM EIA and qPCR assay were characterized by receiver operator curve analysis. With an optimal cutoff of 0.75, the GM EIA had a sensitivity and specificity of 100% in untreated controls. A decline in sensitivity (92%) was observed when antifungal therapy (AFT) was administered. The optimal cutoff for qPCR was a crossover of 36 cycles, with sensitivity and specificity of 80% and 100%, respectively. The sensitivity of qPCR also decreased with AFT to 50%. Quantitative culture of BAL had a sensitivity of 46% and a specificity of 100%. The sensitivity of quantitative culture decreased with AFT to 16%. The GM EIA and qPCR assay had greater sensitivity than culture in detection of A. fumigatus in BAL fluid in experimentally induced IPA (P ± 0.04). Use of the GM EIA and qPCR assay in conjunction with culture-based diagnostic methods applied to BAL fluid could facilitate accurate diagnosis and more-timely initiation of specific therapy. PMID:16825367

Accuracy of Raman spectroscopy in differentiating brain tumor from normal brain tissue.

PubMed

Zhang, Jing; Fan, Yimeng; He, Min; Ma, Xuelei; Song, Yanlin; Liu, Ming; Xu, Jianguo

2017-05-30

Raman spectroscopy could be applied to distinguish tumor from normal tissues. This meta-analysis was conducted to assess the accuracy of Raman spectroscopy in differentiating brain tumor from normal brain tissue. PubMed and Embase were searched to identify suitable studies prior to Jan 1st, 2016. We estimated the pooled sensitivity, specificity, positive and negative likelihood ratios (LR), diagnostic odds ratio (DOR), and constructed summary receiver operating characteristics (SROC) curves to identity the accuracy of Raman spectroscopy in differentiating brain tumor from normal brain tissue. A total of six studies with 1951 spectra were included. For glioma, the pooled sensitivity and specificity of Raman spectroscopy were 0.96 (95% CI 0.94-0.97) and 0.99 (95% CI 0.98-0.99), respectively. The area under the curve (AUC) was 0.9831. For meningioma, the pooled sensitivity and specificity were 0.98 (95% CI 0.94-1.00) and 1.00 (95% CI 0.98-1.00), respectively. The AUC was 0.9955. This meta-analysis suggested that Raman spectroscopy could be an effective and accurate tool for differentiating glioma and meningioma from normal brain tissue, which would help us both avoid removal of normal tissue and minimize the volume of residual tumor.

The Diagnostic Value of Gastrin-17 Detection in Atrophic Gastritis

PubMed Central

Wang, Xu; Ling, Li; Li, Shanshan; Qin, Guiping; Cui, Wei; Li, Xiang; Ni, Hong

2016-01-01

Abstract A meta-analysis was performed to assess the diagnostic value of gastrin-17 (G-17) for the early detection of chronic atrophic gastritis (CAG). An extensive literature search was performed, with the aim of selecting publications that reported the accuracy of G-17 in predicting CAG, in the following databases: PubMed, Science Direct, Web of Science, Chinese Biological Medicine, Chinese National Knowledge Infrastructure, Wanfang, and VIP. To assess the diagnostic value of G-17, the following statistics were estimated and described: sensitivity, specificity, diagnostic odds ratios (DOR), summary receiver operating characteristic curves, area under the curve (AUC), and 95% confidence intervals (CIs). Thirteen studies that met the inclusion criteria were included in this meta-analysis, comprising 894 patients and 1950 controls. The pooled sensitivity and specificity of these studies were 0.48 (95% CI: 0.45–0.51) and 0.79 (95% CI: 0.77–0.81), respectively. The DOR was 5.93 (95% CI: 2.93–11.99), and the AUC was 0.82. G-17 may have potential diagnostic value because it has good specificity and a moderate DOR and AUC for CAG. However, more studies are needed to improve the sensitivity of this diagnostic tool in the future. PMID:27149493

Evaluation of end-tidal CO2 pressure at the anaerobic threshold for detecting and assessing pulmonary hypertension.

PubMed

Higashi, Akifumi; Dohi, Yoshihiro; Yamabe, Sayuri; Kinoshita, Hiroki; Sada, Yoshiharu; Kitagawa, Toshiro; Hidaka, Takayuki; Kurisu, Satoshi; Yamamoto, Hideya; Yasunobu, Yuji; Kihara, Yasuki

2017-11-01

Cardiopulmonary exercise testing (CPET) is useful for the evaluation of patients with suspected or confirmed pulmonary hypertension (PH). End-tidal carbon dioxide pressure (PETCO 2 ) during exercise is reduced with elevated pulmonary artery pressure. However, the utility of ventilatory parameters such as CPET for detecting PH remains unclear. We conducted a review in 155 patients who underwent right heart catheterization and CPET. Fifty-nine patients had PH [mean pulmonary arterial pressure (mPAP) ≥25 mmHg]. There was an inverse correlation between PETCO 2 at the anaerobic threshold (AT) and mPAP (r = -0.66; P < 0.01). Multiple regression analysis showed that PETCO 2 at the AT was independently associated with an elevated mPAP (P = 0.04). The sensitivity and specificity of CPET for PH were 80 and 86%, respectively, when the cut-off value identified by receiver operating characteristic curve analysis for PETCO 2 at the AT was ≤34.7 mmHg. A combination of echocardiography and CPET improved the sensitivity in detecting PH without markedly reducing specificity (sensitivity 87%, specificity 85%). Evaluation of PETCO 2 at the AT is useful for estimating pulmonary pressure. A combination of CPET and previous screening algorithms for PH may enhance the diagnostic ability of PH.

Diagnostic Accuracy of F-18 FDG PET/CT for Preoperative Lymph Node Staging in Newly Diagnosed Bladder Cancer Patients: A Systematic Review and Meta-Analysis.

PubMed

Ha, Hong Ku; Koo, Phillip J; Kim, Seong-Jang

2018-05-30

We aimed to assess the diagnostic accuracy of F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for preoperative lymph node (LN) staging in newly diagnosed bladder cancer (BC) patients through a systematic review and meta-analysis. MEDLINE, Embase, and the Cochrane Library database, from the earliest available date of indexing through June 30, 2017, were searched for studies evaluating the diagnostic performance of F-18 FDG PET/CT for preoperative LN staging in newly diagnosed BC. We determined the sensitivities and specificities across studies, calculated positive and negative likelihood ratios (LR+ and LR-), and constructed summary receiver operating characteristic curves. Across 14 studies (785 patients), the pooled sensitivity was 0.57 (95% CI: 0.49-0.64) and the pooled specificity was 0.92 (95% CI: 0.87-0.95). The LR syntheses gave an overall LR+ of 7.4 (95% CI: 4.4-12.3) and an LR- of 0.47 (95% CI: 0.39-0.56). The pooled diagnostic odds ratio was 16 (95% CI: 9-28). F-18 FDG PET/CT shows a low sensitivity and high specificity for the detection of metastatic LNs in patients with newly diagnosed BC. © 2018 S. Karger AG, Basel.

Mean cerebral blood volume is an effective diagnostic index of recurrent and radiation injury in glioma patients: A meta-analysis of diagnostic test.

PubMed

Li, Zhanzhan; Zhou, Qin; Li, Yanyan; Yan, Shipeng; Fu, Jun; Huang, Xinqiong; Shen, Liangfang

2017-02-28

We conducted a meta-analysis to evaluate the diagnostic values of mean cerebral blood volume for recurrent and radiation injury in glioma patients. We performed systematic electronic searches for eligible study up to August 8, 2016. Bivariate mixed effects models were used to estimate the combined sensitivity, specificity, positive likelihood ratios, negative likelihood ratios, diagnostic odds ratios and their 95% confidence intervals (CIs). Fifteen studies with a total number of 576 participants were enrolled. The pooled sensitivity and specificity of diagnostic were 0.88 (95%CI: 0.82-0.92) and 0.85 (95%CI: 0.68-0.93). The pooled positive likelihood ratio is 5.73 (95%CI: 2.56-12.81), negative likelihood ratio is 0.15 (95%CI: 0.10-0.22), and the diagnostic odds ratio is 39.34 (95%CI:13.96-110.84). The summary receiver operator characteristic is 0.91 (95%CI: 0.88-0.93). However, the Deek's plot suggested publication bias may exist (t=2.30, P=0.039). Mean cerebral blood volume measurement methods seems to be very sensitive and highly specific to differentiate recurrent and radiation injury in glioma patients. The results should be interpreted with caution because of the potential bias.

Identification of 11-Nor-delta9-tetrahydrocannabinol-9-carboxylic acid in urine by ion trap GC-MS-MS in the context of doping analysis.

PubMed

Caballero, Gerardo M; D'Angelo, Carlos; Fraguío, Mariá Sol; Centurión, Osvaldo Teme

2004-01-01

The purpose of this study is to develop a sensitive and specific alternative to current gas chromatography (GC)-mass spectrometry (MS) selected ion monitoring confirmation methods of 11-nor-delta9-tetrahydrocannabinol-9-carboxylic acid (cTHC) in human urine samples, in the context of doping analysis. An identification procedure based on the comparison, among suspicious and control samples, of the relative abundances of cTHC selected product ions obtained by GC-tandem MS in an ion trap is presented. The method complies with the identification criteria for qualitative assays established by sports authorities; the comparison procedure is precise, reproducible, specific, and sensitive, thus indicating that it is fit for the purpose of identification accordingly to World Antidoping Agency requirements.

FDG-PET/CT for treatment response assessment in head and neck squamous cell carcinoma: a systematic review and meta-analysis of diagnostic performance.

PubMed

Helsen, Nils; Van den Wyngaert, Tim; Carp, Laurens; Stroobants, Sigrid

2018-06-01

18-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) is increasingly used to evaluate treatment response in head and neck squamous cell carcinoma (HNSCC). This analysis assessed the diagnostic value of FDG-PET/CT in detecting nodal disease within 6 months after treatment, considering patient and disease characteristics. A systematic review was performed using the MEDLINE and Web of Knowledge databases. The results were pooled using a bivariate random effects model of the sensitivity and specificity. Out of 22 identified studies, a meta-analysis of 20 studies (1293 patients) was performed. The pooled estimates of sensitivity, specificity and diagnostic odds ratio (with 95% CI) were 85% (76-91%), 93% (89-96%) and 76 (35-165), respectively. With the prevalence set at 10%, the positive and negative predictive values were 58% and 98%. There was significant heterogeneity between the trials (p < 0.001). HPV positive tumors were associated with lower sensitivity (75% vs 89%; p = 0.01) and specificity (87% vs 95%; p < 0.005). FDG-PET/CT within 6 months after (chemo)radiotherapy in HNSCC patients is a reliable method for ruling out residual/recurrent nodal disease and obviates the need for therapeutic intervention. However, FDG-PET/CT may be less reliable in HPV positive tumors and the optimal surveillance strategy remains to be determined.

The receiver operational characteristic for binary classification with multiple indices and its application to the neuroimaging study of Alzheimer's disease.

PubMed

Wu, Xia; Li, Juan; Ayutyanont, Napatkamon; Protas, Hillary; Jagust, William; Fleisher, Adam; Reiman, Eric; Yao, Li; Chen, Kewei

2013-01-01

Given a single index, the receiver operational characteristic (ROC) curve analysis is routinely utilized for characterizing performances in distinguishing two conditions/groups in terms of sensitivity and specificity. Given the availability of multiple data sources (referred to as multi-indices), such as multimodal neuroimaging data sets, cognitive tests, and clinical ratings and genomic data in Alzheimer’s disease (AD) studies, the single-index-based ROC underutilizes all available information. For a long time, a number of algorithmic/analytic approaches combining multiple indices have been widely used to simultaneously incorporate multiple sources. In this study, we propose an alternative for combining multiple indices using logical operations, such as “AND,” “OR,” and “at least n” (where n is an integer), to construct multivariate ROC (multiV-ROC) and characterize the sensitivity and specificity statistically associated with the use of multiple indices. With and without the “leave-one-out” cross-validation, we used two data sets from AD studies to showcase the potentially increased sensitivity/specificity of the multiV-ROC in comparison to the single-index ROC and linear discriminant analysis (an analytic way of combining multi-indices). We conclude that, for the data sets we investigated, the proposed multiV-ROC approach is capable of providing a natural and practical alternative with improved classification accuracy as compared to univariate ROC and linear discriminant analysis.

The Receiver Operational Characteristic for Binary Classification with Multiple Indices and Its Application to the Neuroimaging Study of Alzheimer’s Disease

PubMed Central

Wu, Xia; Li, Juan; Ayutyanont, Napatkamon; Protas, Hillary; Jagust, William; Fleisher, Adam; Reiman, Eric; Yao, Li; Chen, Kewei

2014-01-01

Given a single index, the receiver operational characteristic (ROC) curve analysis is routinely utilized for characterizing performances in distinguishing two conditions/groups in terms of sensitivity and specificity. Given the availability of multiple data sources (referred to as multi-indices), such as multimodal neuroimaging data sets, cognitive tests, and clinical ratings and genomic data in Alzheimer’s disease (AD) studies, the single-index-based ROC underutilizes all available information. For a long time, a number of algorithmic/analytic approaches combining multiple indices have been widely used to simultaneously incorporate multiple sources. In this study, we propose an alternative for combining multiple indices using logical operations, such as “AND,” “OR,” and “at least n” (where n is an integer), to construct multivariate ROC (multiV-ROC) and characterize the sensitivity and specificity statistically associated with the use of multiple indices. With and without the “leave-one-out” cross-validation, we used two data sets from AD studies to showcase the potentially increased sensitivity/specificity of the multiV-ROC in comparison to the single-index ROC and linear discriminant analysis (an analytic way of combining multi-indices). We conclude that, for the data sets we investigated, the proposed multiV-ROC approach is capable of providing a natural and practical alternative with improved classification accuracy as compared to univariate ROC and linear discriminant analysis. PMID:23702553

Detection of Delta9-tetrahydrocannabinol and amphetamine-type stimulants in oral fluid using the Rapid Stat point-of-collection drug-testing device.

PubMed

Röhrich, J; Zörntlein, S; Becker, J; Urban, R

2010-04-01

The Rapid Stat assay, a point-of-collection drug-testing device for detection of amphetamines, cannabinoids, cocaine, opiates, methadone, and benzodiazepines in oral fluid, was evaluated for cannabis and amphetamine-type stimulants. The Rapid Stat tests (n = 134) were applied by police officers in routine traffic checks. Oral fluid and blood samples were analyzed using gas chromatography-mass spectrometry (GC-MS) for Delta(9)-tetrahydrocannabinol, amphetamine, methamphetamine, methylenedioxymethamphetamine, methylenedioxyethylamphetamine, and methylenedioxyamphetamine. The comparison of GC-MS analysis of oral fluid with the Rapid Stat results for cannabis showed a sensitivity of 85%, a specificity of 87%, and a total confirmation rate of 87%. When compared with serum, the sensitivity of the cannabis assay decreased to 71%, the specificity to 60%, and the total confirmation rate to 66%. These findings were possibly caused by an incorrect reading of the THC test results. Comparison of the Rapid Stat amphetamine assay with GC-MS in oral fluid showed a sensitivity of 94%, a specificity of 97%, and a total confirmation rate of 97%. Compared with serum, a sensitivity of 100%, a specificity of 90%, and a total confirmation rate of 92% was found. The amphetamine assay must, therefore, be regarded as satisfactory.

Effects of prevalence on visual search and decision making in fracture detection

NASA Astrophysics Data System (ADS)

Ethell, Susan C.; Manning, David

2001-06-01

Research concerning disease prevalence has inferred that indices of observer performance become, in part, a function of predetermined prevalence. The cause of this modified performance and decision-making is not fully understood, although the alteration of the criterion level of the observer may be a feature. Novice radiography students were randomly assigned to one of three digitised test banks of 72 wrist images. Test bank A, B and C represented a fracture prevalence of 50%, 83% and 22% respectively. Half of the observers from each group were made aware of the prevalence of their respective test bank. Observers recorded their decisions on an operator rating scale. Results showed significant differences in overall Az between the 50% and 83% prevalence sets (p equals 0.04) and the 50% and 22% prevalence sets (p equals 0.005). Knowledge of the prevalence influenced both sensitivity and specificity values at the 83% prevalence level (p equals 0.03 and 0.02) but not at the lower levels. For test bank A sensitivity was 87%; specificity 53%; Az 0.80, test bank B sensitivity 81%; specificity 48%; Az 0.71 and test bank C sensitivity 85%; specificity 43%; Az 0.68. Analysis of the eye movement patterns of observers under conditions of varying prevalence is in progress.

Molecular beacon probes-base multiplex NASBA Real-time for detection of HIV-1 and HCV.

PubMed

Mohammadi-Yeganeh, S; Paryan, M; Mirab Samiee, S; Kia, V; Rezvan, H

2012-06-01

Developed in 1991, nucleic acid sequence-based amplification (NASBA) has been introduced as a rapid molecular diagnostic technique, where it has been shown to give quicker results than PCR, and it can also be more sensitive. This paper describes the development of a molecular beacon-based multiplex NASBA assay for simultaneous detection of HIV-1 and HCV in plasma samples. A well-conserved region in the HIV-1 pol gene and 5'-NCR of HCV genome were used for primers and molecular beacon design. The performance features of HCV/HIV-1 multiplex NASBA assay including analytical sensitivity and specificity, clinical sensitivity and clinical specificity were evaluated. The analysis of scalar concentrations of the samples indicated that the limit of quantification of the assay was <1000 copies/ml for HIV-1 and <500 copies/ml for HCV with 95% confidence interval. Multiplex NASBA assay showed a 98% sensitivity and 100% specificity. The analytical specificity study with BLAST software demonstrated that the primers do not attach to any other sequences except for that of HIV-1 or HCV. The primers and molecular beacon probes detected all HCV genotypes and all major variants of HIV-1. This method may represent a relatively inexpensive isothermal method for detection of HIV-1/HCV co-infection in monitoring of patients.

The sensitivity and specificity of touch preparation for rapid diagnosis of invasive fungal sinusitis: A pilot study.

PubMed

Schuman, Theodore A; Nguyen, Josephine H; Yelverton, Joshua C; Almenara, Jorge A; Powers, Celeste N

2018-01-01

Invasive fungal sinusitis is a morbid pathology that typically affects immunocompromised patients and may quickly progress to fulminant disease. The purpose of this study was to measure the sensitivity and specificity of touch preparation of nasal debridement specimens as a rapid diagnostic tool for invasive fungal sinusitis. A retrospective chart review was performed of 22 patients undergoing nasal debridement due to suspicion for invasive fungal sinusitis over a 10-year period. Thirteen patients had touch preparation of nasal specimens followed by routine histologic processing; 2 of these patients underwent two and 1 patient had three separate debridements, for a total of 17 touch preparations performed. The sensitivity and specificity of touch preparation were calculated by correlating the initial results with the presence of fungal invasion on final pathologic analysis. The sensitivity of touch preparation was 56% (95% confidence interval [CI]: 0.23 to 0.85), specificity was 100% (95% CI: 0.60 to 1.00), positive predictive value was 100% (95% CI: 0.46 to 1.00), and negative predictive value was 67% (95% CI: 0.35 to 0.89). This procedure may be a useful adjunct in situations requiring rapid diagnosis of invasive fungal sinusitis but should not be used as the sole criterion for determining the need for surgical intervention.

Accelerometric gait analysis for use in hospital outpatients.

PubMed

Auvinet, B; Chaleil, D; Barrey, E

1999-01-01

To provide clinicians with a quantitative human gait analysis tool suitable for routine use. We evaluated the reproducibility, sensitivity, and specificity of gait analysis based on measurements of acceleration at a point near the center of gravity of the body. Two accelerometers held over the middle of the low back by a semi-elastic belt were used to record craniocaudal and side-to-side accelerations at a frequency of 50 Hz. Subjects were asked to walk at their normal speed to the end of a straight 40 meter-long hospital corridor and back. A 20-second period of stabilized walking was used to calculate cycle frequency, stride symmetry, and stride regularity. Symmetry and regularity were each derived from an auto-correlation coefficient; to convert their distribution from nonnormal to normal, Fisher's Z transformation was applied to the auto-coefficients for these two variables. Intraobserver reproducibility was evaluated by asking the same observer to test 16 controls on three separate occasions at two-day intervals and interobserver reproducibility by asking four different observers to each test four controls (Latin square). Specificity and sensitivity were determined by testing 139 controls and 63 patients. The 139 controls (70 women and 69 men) were divided into five age groups (third through seventh decades of life). The 63 patients had a noninflammatory musculoskeletal condition predominating on one side. ROC curves were used to determine the best cutoffs for separating normal from abnormal values. Neither intra- nor interobserver variability was significant (P > 0.05). Cycle frequency was significantly higher in female than in male controls (1.05 +/- 0.06 versus 0.98 +/- 0.05 cycles/s; P < 0.001). Neither symmetry nor regularity were influenced by gender in the controls; both variables were also unaffected by age, although nonsignificant decreases were found in the 61 to 70-year age group, which included only nine subjects. In the ROC curve analysis, the area under the curve was high for all three variables (frequency, 0.81 +/- 0.04; symmetry, 0.85 +/- 0.03; and regularity, 0.88 +/- 0.03), establishing that there was a good compromise between sensitivity and specificity. Our gait analysis method offers satisfactory reproducibility and is sufficiently sensitive and specific to be used by clinicians in the quantitative evaluation of gait abnormalities.

Clinical evaluation of a novel population-based regression analysis for detecting glaucomatous visual field progression.

PubMed

Kovalska, M P; Bürki, E; Schoetzau, A; Orguel, S F; Orguel, S; Grieshaber, M C

2011-04-01

The distinction of real progression from test variability in visual field (VF) series may be based on clinical judgment, on trend analysis based on follow-up of test parameters over time, or on identification of a significant change related to the mean of baseline exams (event analysis). The aim of this study was to compare a new population-based method (Octopus field analysis, OFA) with classic regression analyses and clinical judgment for detecting glaucomatous VF changes. 240 VF series of 240 patients with at least 9 consecutive examinations available were included into this study. They were independently classified by two experienced investigators. The results of such a classification served as a reference for comparison for the following statistical tests: (a) t-test global, (b) r-test global, (c) regression analysis of 10 VF clusters and (d) point-wise linear regression analysis. 32.5 % of the VF series were classified as progressive by the investigators. The sensitivity and specificity were 89.7 % and 92.0 % for r-test, and 73.1 % and 93.8 % for the t-test, respectively. In the point-wise linear regression analysis, the specificity was comparable (89.5 % versus 92 %), but the sensitivity was clearly lower than in the r-test (22.4 % versus 89.7 %) at a significance level of p = 0.01. A regression analysis for the 10 VF clusters showed a markedly higher sensitivity for the r-test (37.7 %) than the t-test (14.1 %) at a similar specificity (88.3 % versus 93.8 %) for a significant trend (p = 0.005). In regard to the cluster distribution, the paracentral clusters and the superior nasal hemifield progressed most frequently. The population-based regression analysis seems to be superior to the trend analysis in detecting VF progression in glaucoma, and may eliminate the drawbacks of the event analysis. Further, it may assist the clinician in the evaluation of VF series and may allow better visualization of the correlation between function and structure owing to VF clusters. © Georg Thieme Verlag KG Stuttgart · New York.

Comparison of Photo Optical Imaging with Musculoskeletal Ultrasound and Clinical Examination in the Assessment of Inflammatory Activity in Proximal Interphalangeal Joints in Rheumatoid Arthritis and Osteoarthritis.

PubMed

Amitai, Isabella; Werner, Stephanie; Schicke, Bernd; Burmester, Gerd-Rüdiger; Minet, Olaf; Zabaryło, Urszula; Backhaus, Marina; Ohrndorf, Sarah

2015-09-01

Lightscan is a novel, rapid, low-cost, easily operated and noninvasive imaging technology used to assess inflammatory activity in proximal interphalangeal (PIP) joints. The results are calculated automatically. To our knowledge, this is the first comparative study of photo optical imaging (POI), with clinical examination (CE), disease activity score at 28 joints (DAS28)-erythrocyte sedimentation rate (ESR), and musculoskeletal ultrasonography (US) in healthy subjects and patients with rheumatoid arthritis (RA) or osteoarthritis (OA). There were 688 PIP joints of both hands examined in 87 subjects (38 RA, 21 OA, 28 healthy) by Lightscan and compared with CE for clinically swollen and tender joints, DAS28-ESR (only RA), and US. With US as reference, POI had a sensitivity of 74% and a specificity of 93%. In the receiver-operating curve (ROC) analysis, the Lightscan showed a higher sensitivity and specificity [area under the curve (AUC) 0.879] for the distinction of healthy subjects versus patients (OA, RA) than US in greyscale (GSUS; AUC 0.797) and power Doppler (PDUS; AUC 0.67). POI correlated significantly with GSUS (r 0.473, p < 0.01) and PDUS (r 0.486, p < 0.01). The agreement rates between POI and GSUS were up to 79%, between POI and PDUS up to 92%, and between POI and CE up to 66%. POI did not correlate with DAS28-ESR. The Lightscan is a new technology offering sensitive imaging detection of inflammatory changes in subjects with RA and OA with PIP arthritis. POI was more sensitive than CE and correlated significantly to GSUS and PDUS, while presenting a higher sensitivity and specificity for the detection of healthy subjects versus patients (RA, OA) based on the ROC analysis.

CSF lactate alone is not a reliable indicator of bacterial ventriculitis in patients with ventriculostomies.

PubMed

Hill, Emily; Bleck, Thomas P; Singh, Kamaljit; Ouyang, Bichun; Busl, Katharina M

2017-06-01

In a febrile patient with a ventriculostomy, diagnosing or excluding bacterial or microbial ventriculitis is difficult, as conventional markers in analysis of cerebrospinal fluid (CSF) are not applicable due to presence of blood and inflammation. CSF lactate has been shown to be a useful indicator of bacterial meningitis in CSF obtained via lumbar puncture, but little and heterogenous data exist on patients with ventriculostomies. We reviewed all CSF analyses obtained via ventriculostomy in patients admitted to our tertiary medical center between 2008 and 2013, and constructed receiver operating characteristic (ROC) curves to evaluate the accuracy of CSF lactate concentration in discriminating a positive CSF culture from a negative one in setting of ventriculostomy and prophylactic antibiosis. Among 467 CSF lactate values, there were 22 corresponding CSF cultures with bacterial growth. Sensitivities and specificities for CSF lactate at threshold values 3, 4, 5 and 6mmol/L showed sensitivity and specificity greater than 70% for CSF lactate threshold 4mmol/L. The lowest threshold value of 3mmol/L resulted in higher sensitivity of 81.8%, and the highest chosen threshold value resulted in high specificity of 94.2%, but these values had poor corresponding specificity and sensitivity, respectively. The area under the curve was 0.82 (95% CI 0.72, 0.91). Our data from a large sample of CSF studies in patients with ventriculostomy indicate that no single value of CSF lactate provided both sensitivity and specificity high enough to be regarded as reliable test. Copyright © 2017 Elsevier B.V. All rights reserved.

Analysis of the Sensitivity and Specificity of Noninvasive Imaging Tests for the Diagnosis of Renal Artery Stenosis

PubMed Central

Borelli, Flavio Antonio de Oliveira; Pinto, Ibraim M. F.; Amodeo, Celso; Smanio, Paola E. P.; Kambara, Antonio M.; Petisco, Ana Claudia G.; Moreira, Samuel M.; Paiva, Ricardo Calil; Lopes, Hugo Belotti; Sousa, Amanda G. M. R.

2013-01-01

Background Aging and atherosclerosis are related to renovascular hypertension in elderly individuals. Regardless of comorbidities, renal artery stenosis is itself an important cause of cardiovascular morbidity and mortality. Objective To define the sensitivity, specificity, positive predictive value, and negative predictive value of noninvasive imaging tests used in the diagnosis of renal artery stenosis. Methods In a group of 61 patients recruited, 122 arteries were analized, thus permitting the definition of sensitivity, specificity, and the relative contribution of each imaging study performed (Doppler, scintigraphy and computed tomographic angiography in comparison to renal arteriography). Results The mean age was 65.43 years (standard deviation: 8.7). Of the variables related to the study population that were compared to arteriography, two correlated with renal artery stenosis, renal dysfunction and triglycerides. The median glomerular filtration rate was 52.8 mL/min/m2. Doppler showed sensitivity of 82.90%, specificity of 70%, a positive predictive value of 85% and negative predictive value of 66.70%. For tomography, sensitivity was 66.70%, specificity 80%, positive predictive value 87.50% and negative predictive value 55.20%. With these findings, we could identify the imaging tests that best detected stenosis. Conclusion Tomography and Doppler showed good quality and efficacy in the diagnosis of renal artery stenosis, with Doppler having the advantage of not requiring the use of contrast medium for the assessment of a disease that is common in diabetics and is associated with renal dysfunction and severe left ventricular dysfunction. PMID:24061685

Digital Rectal Examination and Balloon Expulsion Test in the Study of Defecatory Disorders: Are They Suitable as Screening or Excluding Tests?

PubMed

Caetano, Ana C; Santa-Cruz, André; Rolanda, Carla

2016-01-01

Background . Rome III criteria add physiological criteria to symptom-based criteria of chronic constipation (CC) for the diagnosis of defecatory disorders (DD). However, a gold-standard test is still lacking and physiological examination is expensive and time-consuming. Aim . Evaluate the usefulness of two low-cost tests-digital rectal examination (DRE) and balloon expulsion test (BET)-as screening or excluding tests of DD. Methods . We performed a systematic search in PUBMED and MEDLINE. We selected studies where constipated patients were evaluated by DRE or BET. Heterogeneity was assessed and random effect models were used to calculate the sensitivity, specificity, and negative predictive value (NPV) of the DRE and the BET. Results . Thirteen studies evaluating BET and four studies evaluating DRE (2329 patients) were selected. High heterogeneity ( I 2 > 80%) among studies was demonstrated. The studies evaluating the BET showed a sensitivity and specificity of 67% and 80%, respectively. Regarding the DRE, a sensitivity of 80% and specificity of 84% were calculated. NPV of 72% for the BET and NPV of 64% for the DRE were estimated. The sensitivity and specificity were similar when we restrict the analysis to studies using Rome criteria to define CC. The BET seems to perform better when a cut-off time of 2 minutes is used and when it is compared with a combination of physiological tests. Considering the DRE, strict criteria seem to improve the sensitivity but not the specificity of the test. Conclusion . Neither of the low-cost tests seems suitable for screening or excluding DD.

Sensitivity of subject-specific models to errors in musculo-skeletal geometry.

PubMed

Carbone, V; van der Krogt, M M; Koopman, H F J M; Verdonschot, N

2012-09-21

Subject-specific musculo-skeletal models of the lower extremity are an important tool for investigating various biomechanical problems, for instance the results of surgery such as joint replacements and tendon transfers. The aim of this study was to assess the potential effects of errors in musculo-skeletal geometry on subject-specific model results. We performed an extensive sensitivity analysis to quantify the effect of the perturbation of origin, insertion and via points of each of the 56 musculo-tendon parts contained in the model. We used two metrics, namely a Local Sensitivity Index (LSI) and an Overall Sensitivity Index (OSI), to distinguish the effect of the perturbation on the predicted force produced by only the perturbed musculo-tendon parts and by all the remaining musculo-tendon parts, respectively, during a simulated gait cycle. Results indicated that, for each musculo-tendon part, only two points show a significant sensitivity: its origin, or pseudo-origin, point and its insertion, or pseudo-insertion, point. The most sensitive points belong to those musculo-tendon parts that act as prime movers in the walking movement (insertion point of the Achilles Tendon: LSI=15.56%, OSI=7.17%; origin points of the Rectus Femoris: LSI=13.89%, OSI=2.44%) and as hip stabilizers (insertion points of the Gluteus Medius Anterior: LSI=17.92%, OSI=2.79%; insertion point of the Gluteus Minimus: LSI=21.71%, OSI=2.41%). The proposed priority list provides quantitative information to improve the predictive accuracy of subject-specific musculo-skeletal models. Copyright © 2012 Elsevier Ltd. All rights reserved.

Diagnostic value of urinary tissue inhibitor of metalloproteinase-2 and insulin-like growth factor binding protein 7 for acute kidney injury: a meta-analysis.

PubMed

Jia, Hui-Miao; Huang, Li-Feng; Zheng, Yue; Li, Wen-Xiong

2017-03-25

Tissue inhibitor of metalloproteinase-2 (TIMP-2) and insulin-like growth factor binding protein 7 (IGFBP7), inducers of G 1 cell cycle arrest, are two recently discovered good biomarkers for early diagnosis of acute kidney injury (AKI). To obtain a more robust performance measurement, the present meta-analysis was performed, pooling existing studies. Literature in the MEDLINE (via PubMed), Ovid, Embase, and Cochrane Library databases was systematically searched from inception to 12 October 2016. Studies that met the set inclusion and exclusion criteria were identified by two independent investigators. The diagnostic value of urinary [TIMP-2] × [IGFBP7] for AKI was evaluated by pooled sensitivity, specificity, likelihood ratio (LR), diagnostic odds ratio (DOR), and summary receiver operating characteristic (SROC) curve analyses. The causes of heterogeneity were explored by sensitivity and subgroup analyses. A total of nine published and eligible studies assessing 1886 cases were included in this meta-analysis. Early diagnostic value of urinary [TIMP-2] × [IGFBP7] for AKI was assessed using a random-effects model. Pooled sensitivity and specificity with corresponding 95% CIs were 0.83 (95% CI 0.79-0.87, heterogeneity I 2  = 68.8%) and 0.55 (95% CI 0.52-0.57, I 2  = 92.9%), respectively. Pooled positive LR, negative LR, and DOR were 2.37 (95% CI 1.87-2.99, I 2  = 82.6%), 0.30 (95% CI 0.21-0.41, I 2  = 43.4%), and 9.92 (95% CI 6.09-16.18, I 2  = 38.5%), respectively. The AUC estimated by SROC was 0.846 (SE 0.027) with a Q* value of 0.777 (SE 0.026). Sensitivity analysis indicated that one study significantly affected the stability of pooled results. Subgroup analysis showed that population setting and AKI threshold were the key factors causing heterogeneity in pooled sensitivity and specificity. On the basis of recent evidence, urinary [TIMP-2] × [IGFBP7] is an effective predictive factor of AKI. PROSPERO registration number: CRD42016051186 . Registered on 10 November 2016.

Modeling screening, prevention, and delaying of Alzheimer's disease: an early-stage decision analytic model

PubMed Central

2010-01-01

Background Alzheimer's Disease (AD) affects a growing proportion of the population each year. Novel therapies on the horizon may slow the progress of AD symptoms and avoid cases altogether. Initiating treatment for the underlying pathology of AD would ideally be based on biomarker screening tools identifying pre-symptomatic individuals. Early-stage modeling provides estimates of potential outcomes and informs policy development. Methods A time-to-event (TTE) simulation provided estimates of screening asymptomatic patients in the general population age ≥55 and treatment impact on the number of patients reaching AD. Patients were followed from AD screen until all-cause death. Baseline sensitivity and specificity were 0.87 and 0.78, with treatment on positive screen. Treatment slowed progression by 50%. Events were scheduled using literature-based age-dependent incidences of AD and death. Results The base case results indicated increased AD free years (AD-FYs) through delays in onset and a reduction of 20 AD cases per 1000 screened individuals. Patients completely avoiding AD accounted for 61% of the incremental AD-FYs gained. Total years of treatment per 1000 screened patients was 2,611. The number-needed-to-screen was 51 and the number-needed-to-treat was 12 to avoid one case of AD. One-way sensitivity analysis indicated that duration of screening sensitivity and rescreen interval impact AD-FYs the most. A two-way sensitivity analysis found that for a test with an extended duration of sensitivity (15 years) the number of AD cases avoided was 6,000-7,000 cases for a test with higher sensitivity and specificity (0.90,0.90). Conclusions This study yielded valuable parameter range estimates at an early stage in the study of screening for AD. Analysis identified duration of screening sensitivity as a key variable that may be unavailable from clinical trials. PMID:20433705

Modeling screening, prevention, and delaying of Alzheimer's disease: an early-stage decision analytic model.

PubMed

Furiak, Nicolas M; Klein, Robert W; Kahle-Wrobleski, Kristin; Siemers, Eric R; Sarpong, Eric; Klein, Timothy M

2010-04-30

Alzheimer's Disease (AD) affects a growing proportion of the population each year. Novel therapies on the horizon may slow the progress of AD symptoms and avoid cases altogether. Initiating treatment for the underlying pathology of AD would ideally be based on biomarker screening tools identifying pre-symptomatic individuals. Early-stage modeling provides estimates of potential outcomes and informs policy development. A time-to-event (TTE) simulation provided estimates of screening asymptomatic patients in the general population age > or =55 and treatment impact on the number of patients reaching AD. Patients were followed from AD screen until all-cause death. Baseline sensitivity and specificity were 0.87 and 0.78, with treatment on positive screen. Treatment slowed progression by 50%. Events were scheduled using literature-based age-dependent incidences of AD and death. The base case results indicated increased AD free years (AD-FYs) through delays in onset and a reduction of 20 AD cases per 1000 screened individuals. Patients completely avoiding AD accounted for 61% of the incremental AD-FYs gained. Total years of treatment per 1000 screened patients was 2,611. The number-needed-to-screen was 51 and the number-needed-to-treat was 12 to avoid one case of AD. One-way sensitivity analysis indicated that duration of screening sensitivity and rescreen interval impact AD-FYs the most. A two-way sensitivity analysis found that for a test with an extended duration of sensitivity (15 years) the number of AD cases avoided was 6,000-7,000 cases for a test with higher sensitivity and specificity (0.90,0.90). This study yielded valuable parameter range estimates at an early stage in the study of screening for AD. Analysis identified duration of screening sensitivity as a key variable that may be unavailable from clinical trials.

Sensitivity Analysis in RIPless Compressed Sensing

DTIC Science & Technology

2014-10-01

SECURITY CLASSIFICATION OF: The compressive sensing framework finds a wide range of applications in signal processing and analysis. Within this...Analysis of Compressive Sensing Solutions Report Title The compressive sensing framework finds a wide range of applications in signal processing and...compressed sensing. More specifically, we show that in a noiseless and RIP-less setting [11], the recovery process of a compressed sensing framework is

Detection of mRNA by reverse transcription PCR as an indicator of viability in Phytophthora ramorum

Treesearch

Antonio Chimento; Santa Olga Cacciola; Matteo Garbelotto

2008-01-01

Real-Time PCR technologies offer increasing opportunities to detect and study phytopathogenic fungi. They combine the sensitivity of conventional PCR with the generation of a specific fluorescent signal providing both real-time analysis of the reaction kinetics and quantification of specific DNA targets. Before the development of Real-Time PCR and...

Differential sensitivity of melanoma cell lines with BRAFV600E mutation to the specific Raf inhibitor PLX4032

PubMed Central

2010-01-01

Blocking oncogenic signaling induced by the BRAFV600E mutation is a promising approach for melanoma treatment. We tested the anti-tumor effects of a specific inhibitor of Raf protein kinases, PLX4032/RG7204, in melanoma cell lines. PLX4032 decreased signaling through the MAPK pathway only in cell lines with the BRAFV600E mutation. Seven out of 10 BRAFV600E mutant cell lines displayed sensitivity based on cell viability assays and three were resistant at concentrations up to 10 μM. Among the sensitive cell lines, four were highly sensitive with IC50 values below 1 μM, and three were moderately sensitive with IC50 values between 1 and 10 μM. There was evidence of MAPK pathway inhibition and cell cycle arrest in both sensitive and resistant cell lines. Genomic analysis by sequencing, genotyping of close to 400 oncogeninc mutations by mass spectrometry, and SNP arrays demonstrated no major differences in BRAF locus amplification or in other oncogenic events between sensitive and resistant cell lines. However, metabolic tracer uptake studies demonstrated that sensitive cell lines had a more profound inhibition of FDG uptake upon exposure to PLX4032 than resistant cell lines. In conclusion, BRAFV600E mutant melanoma cell lines displayed a range of sensitivities to PLX4032 and metabolic imaging using PET probes can be used to assess sensitivity. PMID:20406486

An improved method for detecting circulating microRNAs with S-Poly(T) Plus real-time PCR

PubMed Central

Niu, Yanqin; Zhang, Limin; Qiu, Huiling; Wu, Yike; Wang, Zhiwei; Zai, Yujia; Liu, Lin; Qu, Junle; Kang, Kang; Gou, Deming

2015-01-01

We herein describe a simple, sensitive and specific method for analysis of circulating microRNAs (miRNA), termed S-Poly(T) Plus real-time PCR assay. This new method is based on our previously developed S-Poly(T) method, in which a unique S-Poly(T) primer is used during reverse-transcription to increase sensitivity and specificity. Further increased sensitivity and simplicity of S-Poly(T) Plus, in comparison with the S-Poly(T) method, were achieved by a single-step, multiple-stage reaction, where RNAs were polyadenylated and reverse-transcribed at the same time. The sensitivity of circulating miRNA detection was further improved by a modified method of total RNA isolation from serum/plasma, S/P miRsol, in which glycogen was used to increase the RNA yield. We validated our methods by quantifying miRNA expression profiles in the sera of the patients with pulmonary arterial hypertension associated with congenital heart disease. In conclusion, we developed a simple, sensitive, and specific method for detecting circulating miRNAs that allows the measurement of 266 miRNAs from 100 μl of serum or plasma. This method presents a promising tool for basic miRNA research and clinical diagnosis of human diseases based on miRNA biomarkers. PMID:26459910

Raman spectral analysis for rapid screening of dengue infection

NASA Astrophysics Data System (ADS)

Mahmood, T.; Nawaz, H.; Ditta, A.; Majeed, M. I.; Hanif, M. A.; Rashid, N.; Bhatti, H. N.; Nargis, H. F.; Saleem, M.; Bonnier, F.; Byrne, H. J.

2018-07-01

Infection with the dengue virus is currently clinically detected according to different biomarkers in human blood plasma, commonly measured by enzyme linked immunosorbent assays, including non-structural proteins (Ns1), immunoglobulin M (IgM) and immunoglobulin G (IgG). However, there is little or no mutual correlation between the biomarkers, as demonstrated in this study by a comparison of their levels in samples from 17 patients. As an alternative, the label free, rapid screening technique, Raman spectroscopy has been used for the characterisation/diagnosis of healthy and dengue infected human blood plasma samples. In dengue positive samples, changes in specific Raman spectral bands associated with lipidic and amino acid/protein content are observed and assigned based on literature and these features can be considered as markers associated with dengue development. Based on the spectroscopic analysis of the current, albeit limited, cohort of samples, Principal Components Analysis (PCA) coupled Factorial Discriminant Analysis, yielded values of 97.95% sensitivity and 95.40% specificity for identification of dengue infection. Furthermore, in a comparison of the normal samples to the patient samples which scored low for only one of the biomarker tests, but high or medium for either or both of the other two, PCA-FDA demonstrated a sensitivity of 97.38% and specificity of 86.18%, thus providing an unambiguous screening technology.

Performance of blend sign in predicting hematoma expansion in intracerebral hemorrhage: A meta-analysis.

PubMed

Yu, Zhiyuan; Zheng, Jun; Guo, Rui; Ma, Lu; Li, Mou; Wang, Xiaoze; Lin, Sen; Li, Hao; You, Chao

2017-12-01

Hematoma expansion is independently associated with poor outcome in intracerebral hemorrhage (ICH). Blend sign is a simple predictor for hematoma expansion on non-contrast computed tomography. However, its accuracy for predicting hematoma expansion is inconsistent in previous studies. This meta-analysis is aimed to systematically assess the performance of blend sign in predicting hematoma expansion in ICH. A systematic literature search was conducted. Original studies about predictive accuracy of blend sign for hematoma expansion in ICH were included. Pooled sensitivity, specificity, positive and negative likelihood ratios were calculated. Summary receiver operating characteristics curve was constructed. Publication bias was assessed by Deeks' funnel plot asymmetry test. A total of 5 studies with 2248 patients were included in this meta-analysis. The pooled sensitivity, specificity, positive and negative likelihood ratios of blend sign for predicting hematoma expansion were 0.28, 0.92, 3.4 and 0.78, respectively. The area under the curve (AUC) was 0.85. No significant publication bias was found. This meta-analysis demonstrates that blend sign is a useful predictor with high specificity for hematoma expansion in ICH. Further studies with larger sample size are still necessary to verify the accuracy of blend sign for predicting hematoma expansion. Copyright © 2017 Elsevier B.V. All rights reserved.

Differentiation of Leishmania species by FT-IR spectroscopy

NASA Astrophysics Data System (ADS)

Aguiar, Josafá C.; Mittmann, Josane; Ferreira, Isabelle; Ferreira-Strixino, Juliana; Raniero, Leandro

2015-05-01

Leishmaniasis is a parasitic infectious disease caused by protozoa that belong to the genus Leishmania. It is transmitted by the bite of an infected female Sand fly. The disease is endemic in 88 countries Desjeux (2001) [1] (16 developed countries and 72 developing countries) on four continents. In Brazil, epidemiological data show the disease is present in all Brazilian regions, with the highest incidences in the North and Northeast. There are several methods used to diagnose leishmaniasis, but these procedures have many limitations, are time consuming, have low sensitivity, and are expensive. In this context, Fourier Transform Infrared Spectroscopy (FT-IR) analysis has the potential to provide rapid results and may be adapted for a clinical test with high sensitivity and specificity. In this work, FT-IR was used as a tool to investigate the promastigotes of Leishmaniaamazonensis, Leishmaniachagasi, and Leishmaniamajor species. The spectra were analyzed by cluster analysis and deconvolution procedure base on spectra second derivatives. Results: cluster analysis found four specific regions that are able to identify the Leishmania species. The dendrogram representation clearly indicates the heterogeneity among Leishmania species. The band deconvolution done by the curve fitting in these regions quantitatively differentiated the polysaccharides, amide III, phospholipids, proteins, and nucleic acids. L. chagasi and L. major showed a greater biochemistry similarity and have three bands that were not registered in L. amazonensis. The L. amazonensis presented three specific bands that were not recorded in the other two species. It is evident that the FT-IR method is an indispensable tool to discriminate these parasites. The high sensitivity and specificity of this technique opens up the possibilities for further studies about characterization of other microorganisms.

[Value of Immunohistochemical Methods in Detecting EML4-ALK Fusion Mutations: A Meta-analysis].

PubMed

Liu, Chang; Cai, Lu; Zhong, Diansheng; Wang, Jing

2016-01-01

The fusion between echinoderm microtubule-associated protein 4 (EML4) and anaplastic lymphatic tumor kinase (ALK) rearrangement is present in approximately 5% of non-small cell lung cancer (NSCLC) patients. It has been regarded as another new target gene after epidermal growth factor receptor (EGFR) and K-ras. Figures showed that the disease control rate could reach up to 80% in NSCLC patients with EML4-ALK fusion gene after treated with ALK inhibitors. Thus, exploring an accurate and rapid detecting method is the key in screening NSCLC patients with EML4-ALK expressions. The aim of this study is to analyze the specificity and sensitivity of IHC in detecting EML4-ALK fusion mutations. To evaluate the accuracy and clinical value of this method, and then provide basis for individual molecular therapy of NSCLC patients. Using Pubmed database to search all documents required. The deadline of retrieval was February 25, 2015. Then further screening the articles according to the inclusion and exclusion criteria. Using diagnostic test meta-analysis methods to analyze the sensitivity and specificity of the immunohistochemistry (IHC) method compared with fluorescence in situ hybridization (FISH) method. Eleven literatures were added into the meta analysis, there were 3,234 of total cases. The diagnostic odds ratio (DOR) was 1,135.00 (95%CI: 337.10-3,821.46); the area under curve (AUC) of summary receiver operating characteristic curve (SROC) curve was 0.992,3 (SEAUC=0.003,2), the Q* was 0.964,4 (SEQ*=0.008,7). Immunohistochemical detection of EML4-ALK fusion gene mutation with specific antibody is feasible. It has high sensitivity and specificity. IHC can be a simple and rapid way in screening EML4-ALK fusion gene mutation and exhibits important clinical values.

Digital obstructive arterial disease can be detected by laser Doppler measurements with high sensitivity and specificity.

PubMed

Mahe, Guillaume; Liedl, David A; McCarter, Charlene; Shepherd, Roger; Gloviczki, Peter; McPhail, Ian R; Rooke, Thom W; Wennberg, Paul W

2014-04-01

This study was conducted to determine the sensitivity and specificity of laser Doppler flowmetry (LDF) measurements for digital obstructive arterial disease (DOAD) using angiography as the reference standard and to compare the accuracy of different classical tests used to assess DOAD. Diagnosis of vascular abnormalities at the digital level is challenging. Angiography is the gold standard for assessment of DOAD but is invasive and expensive to perform. We performed a retrospective analysis of consecutive patients referred at Mayo Clinic (Rochester, Minn) for upper extremity arterial assessment during a 27-month period. Finger-brachial index, skin blood flow (in arbitrary units [a.u.]), and skin temperature (in degrees Celsius) were recorded in each digit on the pulp at baseline and after a thermal challenge test (hand placed in a thermal box at 47.0°C for 15 minutes). Angiogram analysis was blinded and performed by a radiologist using a vascularization scale ranging from 0 (no vessel) to 4 (normal). The receiver operating characteristic curve was used to define a specific cutoff point to detect DOAD. Twenty-two patients had LDF measurements and complete angiograms. A total of 185 digits were analyzed because some patients had only analysis of one hand. The best area under the curve (AUC) was 0.98 (range, 0.94-0.99) for postwarming skin blood flow, with a cutoff point of ≤206 a.u. This AUC was statistically different from AUCs of all the other tests (P < .01). Sensitivity and specificity were 93% (95% confidence interval, 85%-97%) and 96% (95% confidence interval, 90%-99%), respectively. LDF combined with a thermal challenge is highly accurate, safe, and noninvasive means to detect DOAD. Copyright © 2014 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.

Prevalence of allergic sensitization in the U.S.: Results from the National Health and Nutrition Examination Survey (NHANES) 2005–2006

PubMed Central

Salo, Päivi M.; Arbes, Samuel J.; Jaramillo, Renee; Calatroni, Agustin; Weir, Charles H.; Sever, Michelle L.; Hoppin, Jane A.; Rose, Kathryn M.; Liu, Andrew H.; Gergen, Peter J.; Mitchell, Herman E.; Zeldin, Darryl C.

2014-01-01

Background Allergic sensitization is an important risk factor for the development of atopic disease. The National Health and Nutrition Examination Survey (NHANES) 2005–2006 provides the most comprehensive information on IgE-mediated sensitization in the general US population. Objective We investigated clustering, sociodemographic and regional patterns of allergic sensitization and examined risk factors associated with IgE-mediated sensitization. Methods Data for this cross-sectional analysis were obtained from NHANES 2005–2006. Participants aged ≥1 year (N=9440) were tested for sIgEs to inhalant and food allergens; participants ≥6 years were tested for 19 sIgEs, and children aged 1–5 years for 9 sIgEs. Serum samples were analyzed using the ImmunoCAP System. Information on demographics and participant characteristics was collected by questionnaire. Results Of the study population aged 6 and older, 44.6% had detectable sIgEs, while 36.2% of children aged 1–5 years were sensitized to ≥1 allergen. Allergen-specific IgEs clustered into 7 groups that might have largely reflected biological cross-reactivity. Although sensitization to individual allergens and allergen types showed regional variation, the overall prevalence of sensitization did not differ across census regions, except in early childhood. In multivariate modeling, young age, male gender, non-Hispanic black race/ethnicity, geographic location (census region), and reported pet avoidance measures were most consistently associated with IgE-mediated sensitization. Conclusions The overall prevalence of allergic sensitization does not vary across US census regions, except in early life, although allergen-specific sensitization differs by sociodemographic and regional factors. Biological cross-reactivity may be an important, but not a sole, contributor to the clustering of allergen-specific IgEs. Clinical implications IgE-mediated sensitization shows clustering patterns and differs by sociodemographic and regional factors, but the overall prevalence of sensitization may not vary across US census regions. PMID:24522093

Sensitive and Specific Target Sequences Selected from Retrotransposons of Schistosoma japonicum for the Diagnosis of Schistosomiasis

PubMed Central

Xu, Jing; Zhu, Xing-Quan; Wang, Sheng-Yue; Xia, Chao-Ming

2012-01-01

Background Schistosomiasis japonica is a serious debilitating and sometimes fatal disease. Accurate diagnostic tests play a key role in patient management and control of the disease. However, currently available diagnostic methods are not ideal, and the detection of the parasite DNA in blood samples has turned out to be one of the most promising tools for the diagnosis of schistosomiasis. In our previous investigations, a 230-bp sequence from the highly repetitive retrotransposon SjR2 was identified and it showed high sensitivity and specificity for detecting Schistosoma japonicum DNA in the sera of rabbit model and patients. Recently, 29 retrotransposons were found in S. japonicum genome by our group. The present study highlighted the key factors for selecting a new perspective sensitive target DNA sequence for the diagnosis of schistosomiasis, which can serve as example for other parasitic pathogens. Methodology/Principal Findings In this study, we demonstrated that the key factors based on the bioinformatic analysis for selecting target sequence are the higher genome proportion, repetitive complete copies and partial copies, and active ESTs than the others in the chromosome genome. New primers based on 25 novel retrotransposons and SjR2 were designed and their sensitivity and specificity for detecting S. japonicum DNA were compared. The results showed that a new 303-bp sequence from non-long terminal repeat (LTR) retrotransposon (SjCHGCS19) had high sensitivity and specificity. The 303-bp target sequence was amplified from the sera of rabbit model at 3 d post-infection by nested-PCR and it became negative at 17 weeks post-treatment. Furthermore, the percentage sensitivity of the nested-PCR was 97.67% in 43 serum samples of S. japonicum-infected patients. Conclusions/Significance Our findings highlighted the key factors based on the bioinformatic analysis for selecting target sequence from S. japonicum genome, which provide basis for establishing powerful molecular diagnostic techniques that can be used for monitoring early infection and therapy efficacy to support schistosomiasis control programs. PMID:22479661

Detection of Echinococcus multilocularis by MC-PCR: evaluation of diagnostic sensitivity and specificity without gold standard

PubMed Central

Wahlström, Helene; Comin, Arianna; Isaksson, Mats; Deplazes, Peter

2016-01-01

Introduction A semi-automated magnetic capture probe-based DNA extraction and real-time PCR method (MC-PCR), allowing for a more efficient large-scale surveillance of Echinococcus multilocularis occurrence, has been developed. The test sensitivity has previously been evaluated using the sedimentation and counting technique (SCT) as a gold standard. However, as the sensitivity of the SCT is not 1, test characteristics of the MC-PCR was also evaluated using latent class analysis, a methodology not requiring a gold standard. Materials and methods Test results, MC-PCR and SCT, from a previous evaluation of the MC-PCR using 177 foxes shot in the spring (n=108) and autumn 2012 (n=69) in high prevalence areas in Switzerland were used. Latent class analysis was used to estimate the test characteristics of the MC-PCR. Although it is not the primary aim of this study, estimates of the test characteristics of the SCT were also obtained. Results and discussion This study showed that the sensitivity of the MC-PCR was 0.88 [95% posterior credible interval (PCI) 0.80–0.93], which was not significantly different than the SCT, 0.83 (95% PCI 0.76–0.88), which is currently considered as the gold standard. The specificity of both tests was high, 0.98 (95% PCI 0.94–0.99) for the MC-PCR and 0.99 (95% PCI 0.99–1) for the SCT. In a previous study, using fox scats from a low prevalence area, the specificity of the MC-PCR was higher, 0.999% (95% PCI 0.997–1). One reason for the lower estimate of the specificity in this study could be that the MC-PCR detects DNA from infected but non-infectious rodents eaten by foxes. When using MC-PCR in low prevalence areas or areas free from the parasite, a positive result in the MC-PCR should be regarded as a true positive. Conclusion The sensitivity of the MC-PCR (0.88) was comparable to the sensitivity of SCT (0.83). PMID:26968153

Analysis of Serum Total and Free PSA Using Immunoaffinity Depletion Coupled to SRM: Correlation with Clinical Immunoassay Tests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Tao; Hossain, Mahmud; Schepmoes, Athena A.

2012-08-03

Sandwich immunoassay is the standard technique used in clinical labs for quantifying protein biomarkers for disease detection, monitoring and therapeutic intervention. Albeit highly sensitive, the development of a specific immunoassay is rather time-consuming and associated with extremely high cost due to the requirement for paired immunoaffinity reagents of high specificity. Recently, mass spectrometry-based methods, specifically selected reaction monitoring mass spectrometry (SRM-MS), have been increasingly applied to measure low abundance biomarker candidates in tissue and biofluids, owing to high sensitivity and specificity, simplicity of assay configuration, and great multiplexing capability. In this study, we report for the first time the developmentmore » of immunoaffinity depletion-based workflows and SRM-MS assays that enable sensitive and accurate quantification of total and free prostate-specific antigen (PSA) in serum without the requirement for specific PSA antibodies. With stable isotope dilution and external calibration, low ng/mL level detection of both total and free PSA was consistently achieved in both PSA-spiked female serum samples and actual patient serum samples. Moreover, comparison of the results obtained when SRM PSA assays and conventional immunoassays were applied to the same samples showed very good correlation (R2 values ranging from 0.90 to 0.99) in several independent clinical serum sample sets, including a set of 33 samples assayed in a blinded test. These results demonstrate that the workflows and SRM assays developed here provide an attractive alternative for reliably measuring total and free PSA in human blood. Furthermore, simultaneous measurement of free and total PSA and many other biomarkers can be performed in a single analysis using high-resolution liquid chromatographic separation coupled with SRM-MS.« less

Diagnostic accuracy of functional, imaging and biochemical tests for patients presenting with chest pain to the emergency department: A systematic review and meta-analysis.

PubMed

Iannaccone, Mario; Gili, Sebastiano; De Filippo, Ovidio; D'Amico, Salvatore; Gagliardi, Marco; Bertaina, Maurizio; Mazzilli, Silvia; Rettegno, Sara; Bongiovanni, Federica; Gatti, Paolo; Ugo, Fabrizio; Boccuzzi, Giacomo G; Colangelo, Salvatore; Prato, Silvia; Moretti, Claudio; D'Amico, Maurizio; Noussan, Patrizia; Garbo, Roberto; Hildick-Smith, David; Gaita, Fiorenzo; D'Ascenzo, Fabrizio

2018-01-01

Non-invasive ischaemia tests and biomarkers are widely adopted to rule out acute coronary syndrome in the emergency department. Their diagnostic accuracy has yet to be precisely defined. Medline, Cochrane Library CENTRAL, EMBASE and Biomed Central were systematically screened (start date 1 September 2016, end date 1 December 2016). Prospective studies (observational or randomised controlled trial) comparing functional/imaging or biochemical tests for patients presenting with chest pain to the emergency department were included. Overall, 77 studies were included, for a total of 49,541 patients (mean age 59.9 years). Fast and six-hour highly sensitive troponin T protocols did not show significant differences in their ability to detect acute coronary syndromes, as they reported a sensitivity and specificity of 0.89 (95% confidence interval 0.79-0.94) and 0.84 (0.74-0.9) vs 0.89 (0.78-0.94) and 0.83 (0.70-0.92), respectively. The addition of copeptin to troponin increased sensitivity and reduced specificity, without improving diagnostic accuracy. The diagnostic value of non-invasive tests for patients without troponin increase was tested. Coronary computed tomography showed the highest level of diagnostic accuracy (sensitivity 0.93 (0.81-0.98) and specificity 0.90 (0.93-0.94)), along with myocardial perfusion scintigraphy (sensitivity 0.85 (0.77-0.91) and specificity 0.92 (0.83-0.96)). Stress echography was inferior to coronary computed tomography but non-inferior to myocardial perfusion scintigraphy, while exercise testing showed the lower level of diagnostic accuracy. Fast and six-hour highly sensitive troponin T protocols provide an overall similar level of diagnostic accuracy to detect acute coronary syndrome. Among the non-invasive ischaemia tests for patients without troponin increase, coronary computed tomography and myocardial perfusion scintigraphy showed the highest sensitivity and specificity.

Comparison of Subjective Global Assessment and Protein Energy Wasting Score to Nutrition Evaluations Conducted by Registered Dietitian Nutritionists in Identifying Protein Energy Wasting Risk in Maintenance Hemodialysis Patients.

PubMed

Sum, Simon Siu-Man; Marcus, Andrea F; Blair, Debra; Olejnik, Laura A; Cao, Joyce; Parrott, J Scott; Peters, Emily N; Hand, Rosa K; Byham-Gray, Laura D

2017-09-01

To compare the 7-point subjective global assessment (SGA) and the protein energy wasting (PEW) score with nutrition evaluations conducted by registered dietitian nutritionists in identifying PEW risk in stage 5 chronic kidney disease patients on maintenance hemodialysis. This study is a secondary analysis of a cross-sectional study entitled "Development and Validation of a Predictive energy Equation in Hemodialysis". PEW risk identified by the 7-point SGA and the PEW score was compared against the nutrition evaluations conducted by registered dietitian nutritionists through data examination from the original study (reference standard). A total of 133 patients were included for the analysis. The sensitivity, specificity, positive and negative predictive value (PPV and NPV), positive and negative likelihood ratio (PLR and NLR) of both scoring tools were calculated when compared against the reference standard. The patients were predominately African American (n = 112, 84.2%), non-Hispanic (n = 101, 75.9%), and male (n = 80, 60.2%). Both the 7-point SGA (sensitivity = 78.6%, specificity = 59.1%, PPV = 33.9%, NPV = 91.2%, PLR = 1.9, and NLR = 0.4) and the PEW score (sensitivity = 100%, specificity = 28.6%, PPV = 27.2%, NPV = 100%, PLR = 1.4, and NLR = 0) were more sensitive than specific in identifying PEW risk. The 7-point SGA may miss 21.4% patients having PEW and falsely identify 40.9% of patients who do not have PEW. The PEW score can identify PEW risk in all patients, but 71.4% of patients identified may not have PEW risk. Both the 7-point SGA and the PEW score could identify PEW risk. The 7-point SGA was more specific, and the PEW score was more sensitive. Both scoring tools were found to be clinically confident in identifying patients who were actually not at PEW risk. Copyright © 2017 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.

Management of neonatal sepsis at Muhimbili National Hospital in Dar es Salaam: diagnostic accuracy of C-reactive protein and newborn scale of sepsis and antimicrobial resistance pattern of etiological bacteria.

PubMed

Mkony, Martha Franklin; Mizinduko, Mucho Michael; Massawe, Augustine; Matee, Mecky

2014-12-05

We determined the accuracy of Rubarth's newborn scale of sepsis and C- reactive protein in diagnosing neonatal sepsis and assessed antimicrobial susceptibility pattern of etiological bacteria. This cross sectional study was conducted at Muhimbili National Hospital in Dar es Salaam, Tanzania between July 2012 and March 2013. Neonates suspected to have sepsis underwent physical examination using Rubarth's newborn scale of sepsis (RNSOS). Blood was taken for culture and antimicrobial sensitivity testing, full blood picture and C - reactive protein (CRP) performed 12 hours apart. The efficacy of RNSOS and serial CRP was assessed by calculating sensitivity, specificity, negative and positive predictive values, receiver operating characteristics (ROC) analysis as well as likelihood ratios (LHR) with blood culture result used as a gold standard. Out of 208 blood samples, 19.2% had a positive blood culture. Single CRP had sensitivity and specificity of 87.5% and 70.9% respectively, while RNSOS had sensitivity of 65% and specificity of 79.7%. Serial CRP had sensitivity of 69.0% and specificity of 92.9%. Combination of CRP and RNSOS increased sensitivity to 95.6% and specificity of 56.4%. Combination of two CRP and RNSOS decreased sensitivity to 89.1% but increased specificity to 74%. ROC for CRP was 0.86; and for RNSOS was 0.81. For CRP the LHR for positive test was 3 while for negative test was 0.18, while for RNSOS the corresponding values were 3.24 and for negative test was 0.43. Isolated bacteria were Klebsiella spp 14 (35%), Escherichia coli 12 (22.5%), Coagulase negative staphlococci 9 (30%), Staphylococcus aureus 4 (10%), and Pseudomonas spp 1 (2.5%). The overall resistance to the WHO recommended first line antibiotics was 100%, 92% and 42% for cloxacillin, ampicillin and gentamicin, respectively. For the second line drugs resistance was 45%, 40%, and 7% for ceftriaxone, vancomycin and amikacin respectively. Single CRP in combination with RNSOS can be used for rapid identification of neonates with sepsis due to high sensitivity (95.6%) but cannot exclude those without sepsis due to low specificity (56.4%). Serial CRP done 12hrs apart can be used to exclude non-cases. This study demonstrated very high levels of resistance to the first-line antibiotics.

Validation of time to task performance assessment method in simulation: A comparative design study.

PubMed

Shinnick, Mary Ann; Woo, Mary A

2018-05-01

There is a lack of objective and valid measures for assessing nursing clinical competence which could adversely impact patient safety. Therefore, we evaluated an objective assessment of clinical competence, Time to Task (ability to perform specific, critical nursing care activities within 5 min), and compared it to two subjective measures, (Lasater Clinical Judgement Rubric [LCJR] and common "pass/fail" assessment). Using a prospective, "Known Groups" (Expert vs. Novice nurses) comparative design, Expert nurses (ICU nurses with >5 years of ICU experience) and Novice nurses (senior prelicensure nursing students) participated individually in a simulation of a patient in decompensated heart failure. Fourteen nursing instructors or preceptors, blinded to group assignment, reviewed 28 simulation videos (15 Expert and 13 Novice) and scored them using the LCJR and pass/fail assessments. Time to Task assessment was scored based on time thresholds for specific nursing actions prospectively set by an expert clinical panel. Statistical analysis consisted of Medians Test and sensitivity and specificity analyses. The LCJR total score was significantly different between Experts and Novices (p < 0.01) and revealed adequate sensitivity (ability to correctly identify "Expert" nurses; 0.72) but had a low specificity (ability to correctly identify "Novice" nurses; 0.40). For the subjective measure 'pass/fail', sensitivity was high (0.90) but specificity was low (0.47). The Time to Task measure had statistical significance between Expert and Novice groups (p < 0.01) and sensitivity (0.80) and specificity (0.85) were good. Commonly used subjective measures of clinical nursing competence have difficulties with achieving acceptable specificity. However, an objective measure, Time to Task, had good sensitivity and specificity in differentiating between groups. While more than one assessment instrument should be used to determine nurse competency, an objective measure, such as Time to Task, warrants further study. Copyright © 2018 Elsevier Ltd. All rights reserved.

Rapid Debris Analysis Project Task 3 Final Report - Sensitivity of Fallout to Source Parameters, Near-Detonation Environment Material Properties, Topography, and Meteorology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goldstein, Peter

2014-01-24

This report describes the sensitivity of predicted nuclear fallout to a variety of model input parameters, including yield, height of burst, particle and activity size distribution parameters, wind speed, wind direction, topography, and precipitation. We investigate sensitivity over a wide but plausible range of model input parameters. In addition, we investigate a specific example with a relatively narrow range to illustrate the potential for evaluating uncertainties in predictions when there are more precise constraints on model parameters.

A Comparative Analysis of Coprologic Diagnostic Methods for Detection of Toxoplama gondii in Cats

PubMed Central

Salant, Harold; Spira, Dan T.; Hamburger, Joseph

2010-01-01

The relative role of transmission of Toxoplasma gondii infection from cats to humans appears to have recently increased in certain areas. Large-scale screening of oocyst shedding in cats cannot rely on microscopy because oocyst identification lacks sensitivity and specificity, or on bioassays, which require test animals and weeks before examination. We compared a sensitive and species-specific coprologic–polymerase chain reaction (copro-PCR) for detection of T. gondii infected cats with microscopy and a bioassay. In experimentally infected cats followed over time, microscopy was positive occasionally, and positive copro-PCR and bioassay results were obtained continuously from days 2 to 24 post-infection. The copro-PCR is at least as sensitive and specific as the bioassay and is capable of detecting infective oocysts during cat infection. Therefore, this procedure can be used as the new gold standard for determining potential cat infectivity. Its technologic advantages over the bioassay make it superior for large-scale screening of cats. PMID:20439968

[Validation of the abbreviated Zarit scales for measuring burden syndrome in the primary caregiver of an elderly patient].

PubMed

Vélez Lopera, Johana María; Berbesí Fernández, Dedsy; Cardona Arango, Doris; Segura Cardona, Angela; Ordóñez Molina, Jaime

2012-07-01

To determine which abbreviated Zarit Scale (ZS) better evaluates the burden of the caregiver of an elderly patient in Medellin, Colombia. Validation study. Primary Care setting in the city of Medellin. Primary caregiver of dependent elderly patients over 65 years old. Sensitivity, specificity, positive predictive value, and negative predictive value for the different abbreviated Zarit scales, plus performing a reliability analysis using the Cronbach Alpha coefficient. The abbreviated scales obtained a sensitivity of between 36.84 and 81.58%, specificity between 95.99 and 100%, positive predictive values between 71.05 and 100%, and negative predictive values of between 91.64 and 97.42%. The scale that better determined caregiver burden in Primary Care was the Bedard Screening scale, with a sensitivity of 81.58%, a specificity of 96.35% and positive and negative predictive values of 75.61% and 97.42%, respectively. Copyright © 2010 Elsevier España, S.L. All rights reserved.

The accuracy of pleural ultrasonography in diagnosing complicated parapneumonic pleural effusions.

PubMed

Svigals, Philip Z; Chopra, Amit; Ravenel, James G; Nietert, Paul J; Huggins, John T

2017-01-01

We compared the accuracy of pleural ultrasound versus chest CT versus chest radiograph (CXR) to determine radiographic complexity in predicting a complicated parapneumonic effusion (CPPE) defined by pleural fluid analysis. 66 patients with parapneumonic effusions were identified with complete data. Pleural ultrasound had a sensitivity of 69.2% (95% CI 48.2% to 85.7%) and specificity of 90.0% (95% CI 76.3% to 97.2%). Chest CT had a sensitivity of 76.9% (95% CI 56.3% to 91.0%) and specificity of 65.0% (95% CI 48.3% to 79.4%). CXR had a sensitivity of 61.5% (95% CI 40.6% to 79.8%) and specificity of 60.0% (95% CI 43.3% to 75.1%). Pleural ultrasound appears to be a superior modality to rule in a CPPE when compared with chest CT and CXR. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Application of Sal classification to parotid gland fine-needle aspiration cytology: 10-year retrospective analysis of 312 patients.

PubMed

Kilavuz, Ahmet Erdem; Songu, Murat; İmre, Abdulkadir; Arslanoğlu, Secil; Özkul, Yilmaz; Pinar, Ercan; Ateş, Düzgün

2018-05-01

The accuracy of fine-needle aspiration biopsy (FNAB) is controversial in parotid tumors. We aimed to compare FNAB results with the final histopathological diagnosis and to apply the "Sal classification" to our data and discuss its results and its place in parotid gland cytology. The FNAB cytological findings and final histological diagnosis were assessed retrospectively in 2 different scenarios based on the distribution of nondefinitive cytology, and we applied the Sal classification and determined malignancy rate, sensitivity, and specificity for each category. In 2 different scenarios FNAB sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were found to be 81%, 87%, 54.7%, and 96.1%; and 65.3%, 100%, 100%, and 96.1%, respectively. The malignancy rates and sensitivity and specificity were also calculated and discussed for each Sal category. We believe that the Sal classification has a great potential to be a useful tool in classification of parotid gland cytology. © 2018 Wiley Periodicals, Inc.

Development of an ELISA for sensitive and specific detection of IgA autoantibodies against BP180 in pemphigoid diseases

PubMed Central

2011-01-01

Background Pemphigoids are rare diseases associated with IgG, IgE and IgA autoantibodies against collagen XVII/BP180. An entity of the pemphigoid group is the lamina lucida-type of linear IgA disease (IgA pemphigoid) characterized by IgA autoantibodies against BP180. While for the detection of IgG and IgE autoantibodies specific to collagen XVII several ELISA systems have been established, no quantitative immunoassay has been yet developed for IgA autoantibodies. Therefore, the aim of the present study was to develop an ELISA to detect IgA autoantibodies against collagen XVII in the sera of patients with pemphigoids. Methods We expressed a soluble recombinant form of the collagen XVII ectodomain in mammalian cells. Reactivity of IgA autoantibodies from patients with IgA pemphigoid was assessed by immunofluorescence microscopy and immunoblot analysis. ELISA test conditions were determined by chessboard titration experiments. The sensitivity, specificity and the cut-off were determined by receiver-operating characteristics analysis. Results The optimized assay was carried out using sera from patients with IgA pemphigoid (n = 30) and healthy donors (n = 105). By receiver operating characteristics (ROC) analysis, an area under the curve of 0.993 was calculated, indicating an excellent discriminatory capacity. Thus, a sensitivity and specificity of 83.3% and 100%, respectively, was determined for a cut-off point of 0.48. As additional control groups, sera from patients with bullous pemphigoid (n = 31) and dermatitis herpetiformis (n = 50), a disease associated with IgA autoantibodies against epidermal transglutaminase, were tested. In 26% of bullous pemphigoid patients, IgA autoantibodies recognized the ectodomain of collagen XVII. One of 50 (2%) of dermatitis herpetiformis patients sera slightly topped the cut-off value. Conclusions We developed the first ELISA for the specific and sensitive detection of serum IgA autoantibodies specific to collagen XVII in patients with pemphigoids. This immunoassay should prove a useful tool for clinical and translational research and should essentially improve the diagnosis and disease monitoring of patients with IgA pemphigoid. Moreover, our findings strongly suggest that IgA pemphigoid and IgG bullous pemphigoid represent two ends of the clinical spectrum of an immunological loss of tolerance against components of hemidesmosomes, which is mediated by both IgG and IgA autoantibodies. PMID:21619684

Evaluation of the Diagnostic Utility of the Traditional and Revised WHO Dengue Case Definitions

PubMed Central

Gutiérrez, Gamaliel; Gresh, Lionel; Pérez, María Ángeles; Elizondo, Douglas; Avilés, William; Kuan, Guillermina; Balmaseda, Ángel; Harris, Eva

2013-01-01

Dengue, a mosquito-borne viral illness, is a major public health problem worldwide, and its incidence continues to increase. In 2009, the World Health Organization published guidelines that included a revision of the dengue case definition. Compared to the traditional definition, the revised case definition relies more on signs than on symptoms, making it more applicable to young children. We evaluated the diagnostic utility of both case definitions in two studies of pediatric dengue in Managua, Nicaragua. In a community-based cohort study, we included data from 3,407 suspected dengue cases, of which 476 were laboratory-confirmed. In the second study, we collected information from 1,160 participants recruited at the national pediatric reference hospital (723 laboratory-confirmed). In the cohort study, the traditional definition had 89.3% sensitivity and 43.1% specificity, while the revised definition yielded similar sensitivity (86.6%) and higher specificity (55.2%, p<0.001). In the hospital study, the traditional case definition yielded 96.7% sensitivity and 22.0% specificity, whereas the revised case definition had higher sensitivity (99.3%, p<0.001) but lower specificity (8.5%, p<0.001). We then evaluated the performance of two diagnostic models based on the signs/symptoms included in each definition by analyzing the effect of increasing numbers of signs/symptoms on the sensitivity and specificity of case capture. Receiver operating characteristic analysis showed a slightly better performance for the revised model in both studies. Interestingly, despite containing less symptoms that cannot be readily expressed by children aged less than 4 years, the revised definition did not perform better in this age group. Overall, our results indicate that both case definitions have similar capacity to diagnose dengue. Owing to their high sensitivity and low specificity, they should be primarily used for screening purposes. However, in a primary care setting, neither of the case definitions performed well as a screening test in younger children. PMID:23991237

Diagnostic utility of attenuation measurement (Hounsfield units) in computed tomography stonogram in predicting the radio-opacity of urinary calculi in plain abdominal radiographs.

PubMed

Chua, Michael E; Gatchalian, Glenn T; Corsino, Michael Vincent; Reyes, Buenaventura B

2012-10-01

(1) To determine the best cut-off level of Hounsfield units (HU) in the CT stonogram that would predict the appearance of a urinary calculi in plain KUB X-ray; (2) to estimate the sensitivity and specificity of the best cut-off HU; and (3) to determine whether stone size and location affect the in vivo predictability. A prospective cross-sectional study of patients aged 18-85 diagnosed with urolithiases on CT stonogram with concurrent plain KUB radiograph was conducted. Appearance of stones was recorded, and significant difference between radiolucent and radio-opaque CT attenuation level was determined using ANOVA. Receiver operating characteristics (ROC) curve determined the best HU cut-off value. Stone size and location were used for factor variability analysis. A total of 184 cases were included in this study, and the average urolithiasis size on CT stonogram was 0.84 cm (0.3-4.9 cm). On KUB X-ray, 34.2 % of the urolithiases were radiolucent and 65.8 % were radio-opaque. Mean value of CT Hounsfield unit for radiolucent stones was 358.25 (±156), and that for radio-opaque stones was 816.51 (±274). ROC curve determined the best cut-off value of HU at 498.5, with the sensitivity of 89.3 % and specificity of 87.3 %. For >4 mm stones, the sensitivity was 91.3 % and the specificity was 81.8 %. On the other hand, for =<4 mm stones, the sensitivity was 60 % and the specificity was 89.5 %. Based on the constructed ROC curve, a threshold value of 498.5 HU in CT stonogram was established as cut-off in determining whether a calculus is radio-opaque or radiolucent. The determined overall sensitivity and specificity of the set cut-off HU value are optimal. Stone size but not location affects the sensitivity and specificity.

The cut-off values of anthropometric variables for predicting mild cognitive impairment in Malaysian older adults: a large population based cross-sectional study

PubMed Central

Won, Huiloo; Abdul, Manaf Zahara; Mat Ludin, Arimi Fitri; Omar, Mohd Azahadi; Razali, Rosdinom; Shahar, Suzana

2017-01-01

Purpose Older adults are at risk of mild cognitive impairment (MCI), and simple anthropometric measurements can be used to screen for this condition. Thus, the aim of this study was to explore the cut-off values of body mass index (BMI) and waist circumference (WC) for predicting the risk of MCI in older Malaysian adults. Methods A total of 2,240 Malaysian older adults aged ≥60 years were recruited using multistage random sampling in a population based cross-sectional study. Receiver operating characteristic (ROC) curve was used to determine the cut-off values of BMI and WC with optimum sensitivity and specificity for the detection of MCI. Age, gender, years of education, smoking habit, alcohol consumption, depression, and medical conditions were used as confounding factors in this analysis. Results A BMI cut-off value of 26 kg/m2 (area under the receiver operating characteristic curve [AUC] 0.725; sensitivity 90.5%; specificity 38.8%) was appropriate in identifying the risk of getting MCI in both men and women. The optimum WC cut-offs for likelihood of MCI were 90 cm (AUC 0.745; sensitivity 78.0%; specificity 59.8%) for men and 82 cm (AUC 0.714; sensitivity 84.3%; specificity 49.7%) for women. The optimum calf circumference (CC) cut-off values for identifying MCI were 29 cm (AUC 0.731; sensitivity 72.6%; specificity 61.1%) for men and 26 cm (AUC 0.598; sensitivity 79.1%; specificity 45.3%) for women. Conclusion The cut-off values could be advocated and used as part of the screening of MCI among older Malaysian adults. There is a need to further determine the predictive values of these cut-off points on outcomes through longitudinal study design. PMID:28223785

Sensitivity, specificity and predictive values of anterior chamber tap in cases of bacterial endophthalmitis.

PubMed

Sjoholm-Gomez de Liano, Carl; Soberon-Ventura, Vidal F; Salcedo-Villanueva, Guillermo; Santos-Palacios, Abril; Guerrero-Naranjo, Jose Luis; Fromow-Guerra, Jans; García-Aguirre, Gerardo; Morales-Canton, Virgilio; Velez-Montoya, Raul

2017-01-01

To assess the sensitivity, specificity, positive predictive value and negative predictive value of anterior chamber tap for the diagnosis of bacterial endophthalmitis on a population with high prevalence. Retrospective, single centre, case series study. We reviewed all medical records with clinical diagnosis of bacterial endophthalmitis in our hospital from January 1st, 2000 to December 31st 2014. From each record, we documented general demographic data, best corrected visual acuity and vitreous and aqueous tap microbiological results. All cases were further divided according to the endophthalmitis aetiology to perform individual calculations of sensitivity, specificity, positive predictive value, negative predictive value, accuracy and prevalence. We used the results of the vitreous tap as the gold standard for diagnosis of bacterial endophthalmitis. We excluded those records in which the aqueous and vitreous samples were not taken simultaneously or had an incomplete microbiological report. Significance were assessed with chi squared statistics, with an alpha value of 0.05 for statistical significance. A total of 190 cases fulfilled the inclusion/exclusion criteria. Positive culture rate from vitreous samples was 64.74%. Positive culture rate from aqueous sample was 32.11%. Bacteria isolated from aqueous samples matched those isolated from vitreous samples 78.68% of the time. The overall sensitivity was 38.21%, specificity: 75.51%, positive predictive value: 79.66%, negative predictive value: 32.74% ( p  = 0.08). Subgroup analysis showed that anterior chamber taps in cases of post-surgical endophthalmitis had a moderate to low sensitivity (37.73%), high specificity (93%) and high positive predictive value (95%) ( p  < 0.04). The sensitivity and specificity of anterior chamber tap are low and should not be used for critical therapeutic decisions in patients with suspected bacterial endophthalmitis. In cases of post-surgical endophthalmitis, the result of an anterior chamber tap could be used for therapeutic guidance, but only in conjunction with clinical presentation and in the absence of a better method for diagnosis.

Investigating the Predictive Value of Functional MRI to Appetitive and Aversive Stimuli: A Pattern Classification Approach

PubMed Central

McCabe, Ciara; Rocha-Rego, Vanessa

2016-01-01

Background Dysfunctional neural responses to appetitive and aversive stimuli have been investigated as possible biomarkers for psychiatric disorders. However it is not clear to what degree these are separate processes across the brain or in fact overlapping systems. To help clarify this issue we used Gaussian process classifier (GPC) analysis to examine appetitive and aversive processing in the brain. Method 25 healthy controls underwent functional MRI whilst seeing pictures and receiving tastes of pleasant and unpleasant food. We applied GPCs to discriminate between the appetitive and aversive sights and tastes using functional activity patterns. Results The diagnostic accuracy of the GPC for the accuracy to discriminate appetitive taste from neutral condition was 86.5% (specificity = 81%, sensitivity = 92%, p = 0.001). If a participant experienced neutral taste stimuli the probability of correct classification was 92. The accuracy to discriminate aversive from neutral taste stimuli was 82.5% (specificity = 73%, sensitivity = 92%, p = 0.001) and appetitive from aversive taste stimuli was 73% (specificity = 77%, sensitivity = 69%, p = 0.001). In the sight modality, the accuracy to discriminate appetitive from neutral condition was 88.5% (specificity = 85%, sensitivity = 92%, p = 0.001), to discriminate aversive from neutral sight stimuli was 92% (specificity = 92%, sensitivity = 92%, p = 0.001), and to discriminate aversive from appetitive sight stimuli was 63.5% (specificity = 73%, sensitivity = 54%, p = 0.009). Conclusions Our results demonstrate the predictive value of neurofunctional data in discriminating emotional and neutral networks of activity in the healthy human brain. It would be of interest to use pattern recognition techniques and fMRI to examine network dysfunction in the processing of appetitive, aversive and neutral stimuli in psychiatric disorders. Especially where problems with reward and punishment processing have been implicated in the pathophysiology of the disorder. PMID:27870866

Evaluation of a multiplex immunoassay for bovine respiratory syncytial virus and bovine coronavirus antibodies in bulk tank milk against two indirect ELISAs using latent class analysis.

PubMed

Toftaker, Ingrid; Toft, Nils; Stokstad, Maria; Sølverød, Liv; Harkiss, Gordon; Watt, Neil; O' Brien, Amanda; Nødtvedt, Ane

2018-06-01

Bovine respiratory syncytial virus (BRSV) and bovine coronavirus (BCV) are responsible for respiratory disease and diarrhea in cattle worldwide. The Norwegian control program against these infections is based on herd-level diagnosis using a new multiplex immunoassay. The objective of this study was to estimate sensitivity and specificity across different cut-off values for the MVD-Enferplex BCV/BRSV multiplex, by comparing them to a commercially available ELISA, the SVANOVIR ® BCV-Ab and SVANOVIR ® BRSV-Ab, respectively. We analyzed bulk tank milk samples from 360 herds in a low- and 360 herds in a high-prevalence area. As none of the tests were considered perfect, estimation of test characteristics was performed using Bayesian latent class models. At the manufacturers' recommended cut-off values, the median sensitivity for the BRSV multiplex and the BRSV ELISA was 94.4 [89.8-98.7 95% Posterior Credibility Interval (PCI)] and 99.8 [98.7-100 95% PCI], respectively. The median specificity for the BRSV multiplex was 90.6 [85.5-94.4 95% PCI], but only 57.4 [50.5-64.4 95% PCI] for the BRSV ELISA. However, increasing the cut-off of the BRSV ELISA increased specificity without compromising sensitivity. For the BCV multiplex we found that by using only one of the three antigens included in the test, the specificity increased, without concurrent loss in sensitivity. At the recommended cut-off this resulted in a sensitivity of 99.9 [99.3-100 95% PCI] and specificity of 93.7 [88.8-97.8 95% PCI] for the multiplex and a sensitivity of 99.5 [98.1-100 95% PCI] and a specificity of 99.6 [97.6-100 95% PCI] for the BCV ELISA. Copyright © 2018 Elsevier B.V. All rights reserved.

Cervical VEMP threshold response curve in the identification of Ménière's disease.

PubMed

Zhu, Yi; McPherson, James; Beatty, Charles; Driscoll, Colin; Neff, Brian; Eggers, Scott; Shepard, Neil T

2014-03-01

To investigate the sensitivity/specificity of a shift upward in the most sensitive frequency of the cervical vestibular evoked myogenic potential (cVEMP) threshold-response curve in the identification of Ménière's disease (MD). A secondary purpose was to investigate the clinical characteristics that had an impact on the sensitivity/specificity and to adjust the criteria for a positive shift upward in the cVEMP curve to maximize performance of the test. A retrospective review of patients diagnosed with MD and those without MD. Two hundred ninety-four patients met the inclusion criteria of symptom complaints of spontaneous events of vertigo and a full vestibular and balance evaluation with cVEMP threshold-response curve testing. Two hundred six of these patients were diagnosed with MD, and 88 patients were determined to be non-MD. Review of the patients' medical records was used to extract data on the results of the cVEMP curve, age, gender, duration from time of onset of spontaneous events, pure tone average from hearing test, and water caloric asymmetry. Student's t-test, χ² test, receiver operating characteristic (ROC) curve with area under the curve (AUC), Pearson correlation coefficient, and sensitivity/specificity from 2 × 2 tables were all used in the analysis. Basic sensitivity/specificity for a shift upward in the most sensitive frequency to 1000 Hz in the cVEMP threshold-response curve was 0.47/0.64 respectively. Clinical characteristics that were found to have a significant impact on the sensitivity/specificity were age equal to or above 60 yr and a caloric asymmetry ≥25%. Various combinations of age and caloric with the requirement of a shift upward in the cVEMP curve most sensitive frequency to 1000 Hz resulted in significant but modest improvements in sensitivity/specificity. However, the overall performance was not shown acceptable for routine clinical use with maximum sensitivity at 0.73. Therefore, placing an emphasis on specificity over sensitivity results showed specificity of 0.95 for those under 60 yr and 0.90 for those 60 yr of age or older with sensitivity at 0.20, but only in the context of a ≥25% caloric asymmetry. We recommend the use of the shift upward to 1000 Hz with a caloric asymmetry as the clinical protocol to maximize the use of the cVEMP threshold-response curve for assistance in the identification of MD, in the context of a ≥25% caloric asymmetry. This implies that if the test is negative no interpretation of identification of MD can be made. If the test is positive the results can be used to increase the argument for MD since the probability of the result being a false positive is only 5-10%. American Academy of Audiology.