Reducing false positive rate of fetal monosomy X in non‐invasive prenatal testing using a combined algorithm to detect maternal mosaic monosomy X

2019 ◽  
Vol 39 (4) ◽  
pp. 324-327 ◽  
Author(s):  
Minh‐Duy Phan ◽  
Binh T. Vo ◽  
Thong V. Nguyen ◽  
Nhat‐Thang Tran ◽  
Huong N.T. Trinh ◽  
...  
Keyword(s):  
False Positive ◽  
False Positive Rate ◽  
Prenatal Testing ◽  
Non Invasive ◽  
Monosomy X ◽  
Positive Rate ◽  
Combined Algorithm

scholarly journals New screen on the block: non-invasive prenatal testing for fetal chromosomal abnormalities

2017 ◽  
Vol 9 (4) ◽  
pp. 248 ◽  
Author(s):  
Sara Filoche ◽  
Beverley Lawton ◽  
Angela Beard ◽  
Anthony Dowell ◽  
Peter Stone
Keyword(s):  
False Positive ◽  
Chromosomal Abnormalities ◽  
False Positive Rate ◽  
Prenatal Testing ◽  
Diagnostic Procedures ◽  
First Trimester ◽  
Maternal Blood ◽  
Non Invasive ◽  
Positive Rate ◽  
Trimester Screening

ABSTRACT Non-invasive prenatal testing (NIPT) is a new screen for fetal chromosomal abnormalities. It is a screening test based on technology that involves the analysis of feto-placental DNA that is present in maternal blood. This DNA is then analysed for abnormalities of specific chromosomes (eg 13, 18, 21, X, Y). NIPT has a much higher screening capability for chromosomal abnormalities than current combined first trimester screening, with ~99% sensitivity for trisomy 21 (Down syndrome) and at least a 10-fold higher positive predictive value. The low false-positive rate (1–3%) is one of the most advertised advantages of NIPT. In practice, this could lead to a significant reduction in the number of false-positive tests and the need for invasive diagnostic procedures. NIPT is now suitable for singleton and twin pregnancies and can be performed from ~10 weeks in a pregnancy. NIPT is not currently publicly funded in most countries. However, the increasing availability of NIPT commercially will likely lead to an increase in demand for this as a screening option. Given the high numbers of women who visit a general practitioner (GP) in their first trimester, GPs are well-placed to also offer NIPT as a screening option. A GP’s role in facilitating access to this service will likely be crucial in ensuring equity in access to this technology, and it is important to ensure that they are well supported to do so.

scholarly journals Automatic Contraction Detection Using Uterine Electromyography

2020 ◽  
Vol 10 (20) ◽  
pp. 7014
Author(s):  
Filipa Esgalhado ◽  
Arnaldo G. Batista ◽  
Helena Mouriño ◽  
Sara Russo ◽  
Catarina R. Palma dos Reis ◽  
...  
Keyword(s):  
False Positive ◽  
False Positive Rate ◽  
Electric Signal ◽  
Invasive Technique ◽  
Non Invasive ◽  
Uterine Muscle ◽  
Wavelet Energy ◽  
Positive Rate ◽  
Gestational Week ◽  
Teager Energy

Electrohysterography (EHG) is a promising technique for pregnancy monitoring and preterm risk evaluation. It allows for uterine contraction monitoring as early as the 20th gestational week, and it is a non-invasive technique based on recording the electric signal of the uterine muscle activity from electrodes located in the abdominal surface. In this work, EHG-based contraction detection methodologies are applied using signal envelope features. Automatic contraction detection is an important step for the development of unsupervised pregnancy monitoring systems based on EHG. The exploratory methodologies include wavelet energy, Teager energy, root mean square (RMS), squared RMS, and Hilbert envelope. In this work, two main features were evaluated: contraction detection and its related delineation accuracy. The squared RMS produced the best contraction (97.15 ± 4.66%) and delineation (89.43 ± 8.10%) accuracy and the lowest false positive rate (0.63%). Despite the wavelet energy method having a contraction accuracy (92.28%) below the first-rated method, its standard deviation was the second best (6.66%). The average false positive rate ranged between 0.63% and 4.74%—a remarkably low value.

scholarly journals Clinical performance of Non-invasive prenatal testing for sex chromosomal aneuploidies in Northeast China

2020 ◽  
Author(s):  
Lu Wang ◽  
Rulin Dai ◽  
Qingyang Shi ◽  
Yuting Jiang ◽  
Hongguo Zhang ◽  
...  
Keyword(s):  
False Positive ◽  
Northeast China ◽  
Sex Chromosome ◽  
Clinical Performance ◽  
False Positive Rate ◽  
False Negative ◽  
Prenatal Testing ◽  
Potential Method ◽  
Sequencing Platform ◽  
Non Invasive

Abstract Background: Along with the discovery of cell-free DNA (cfDNA) and the invention of next-generation sequencing (NGS), non-invasive prenatal testing (NIPT) had appeared and been applied for detecting common aneuploidies such as trisomy 21, 18, and 13, with low false-negative and false-positive rates. Recently, it had also been used for sex chromosome aneuploidies (SCAs). To assess the clinical utility of NIPT for SCAs in Northeast China, we collected NIPT data from BGI 500 sequencing platform in the Center for Reproductive Medicine, Center for Prenatal Diagnosis of the First Hospital of Jilin University, and calculate the positive predictive value (PPV) and false positive rate (FPR). Results: A cohort of 14936 samples were analyzed by NIPT, and revealed 70 cases with SCAs high-risk, among them, 40 women agreed to undergo amniocentesis, but as many as 30 ones refused further diagnose. Based on verified fetal karyotype, 30.0% (12/40) were confirmed to be a true positive. Unluckily, the PPV for monosomy X performed 0%. Besides, positive 47,XXX were 46.67% (7/15), 40.00% (2/5) were positive for 47, XYY, and 42.86% (3/7) were positive for 47, XXY.Conclusions: In conclusion, our present results confirmed that NIPT sequenced by BGI 500 demonstrated lowest PPVs for 45,X, but the more accurate prediction for other SCAs, it is still a potential method for SCAs screening. Henceforth, we should focus on how to improve the test utility and provide better services for pregnant women in need.

scholarly journals Increasing maternal age is not a significant cause of false‐positive results for monosomy X in non‐invasive prenatal testing

2020 ◽  
Vol 40 (11) ◽  
pp. 1466-1473
Author(s):  
Rhiannon Sandow ◽  
Fergus P. Scott ◽  
Philip J. Schluter ◽  
Daniel L. Rolnik ◽  
Melody Menezes ◽  
...  
Keyword(s):  
False Positive ◽  
Maternal Age ◽  
Prenatal Testing ◽  
Non Invasive ◽  
Monosomy X ◽  
Positive Results

scholarly journals Clinical Performance of Non-Invasive Prenatal Testing for Sex Chromosomal Aneuploidies in Northeast China

2020 ◽  
Author(s):  
Lu Wang ◽  
Rulin Dai ◽  
Qingyang Shi ◽  
Yuting Jiang ◽  
Hongguo Zhang ◽  
...  
Keyword(s):  
False Positive ◽  
Northeast China ◽  
Sex Chromosome ◽  
Clinical Performance ◽  
False Positive Rate ◽  
False Negative ◽  
Prenatal Testing ◽  
Potential Method ◽  
Sequencing Platform ◽  
Non Invasive

Abstract Background: Along with the discovery of cell-free DNA (cfDNA) and the invention of next-generation sequencing (NGS), non-invasive prenatal testing (NIPT) had appeared and been applied for detecting common aneuploidies such as trisomy 21, 18, and 13, with low false-negative and false-positive rates. Recently, it had also been used for sex chromosome aneuploidies (SCAs). To assess the clinical utility of NIPT for SCAs in Northeast China, we collected NIPT data from BGI 500 sequencing platform in the Center for Reproductive Medicine, Center for Prenatal Diagnosis of the First Hospital of Jilin University, and calculate the positive predictive value (PPV) and false positive rate (FPR). Results: A cohort of 14936 samples were analyzed by NIPT, and revealed 70 cases with SCAs high-risk, among them, 40 women agreed to undergo amniocentesis, but as many as 30 ones refused further diagnose. Based on verified fetal karyotype, 30.0% (12/40) were confirmed to be a true positive. Unluckily, the PPV for monosomy X performed 0%. Besides, positive 47,XXX were 46.67% (7/15), 40.00% (2/5) were positive for 47, XYY, and 42.86% (3/7) were positive for 47, XXY.Conclusions: In conclusion, our present results confirmed that NIPT sequenced by BGI 500 demonstrated lowest PPVs for 45,X, but the more accurate prediction for other SCAs, it is still a potential method for SCAs screening. Henceforth, we should focus on how to improve the test utility and provide better services for pregnant women in need.

Improving diagnosis of acute appendicitis with atypical findings by Tc-99m HMPAO leukocyte scan

2002 ◽  
Vol 41 (01) ◽  
pp. 37-41 ◽  
Author(s):  
S. Shung-Shung ◽  
S. Yu-Chien ◽  
Y. Mei-Due ◽  
W. Hwei-Chung ◽  
A. Kao
Keyword(s):  
Acute Appendicitis ◽  
False Positive ◽  
False Positive Rate ◽  
Accurate Method ◽  
Clinical Findings ◽  
Pathological Findings ◽  
Lower Quadrant ◽  
Predictive Values ◽  
Positive Rate

Summary Aim: Even with careful observation, the overall false-positive rate of laparotomy remains 10-15% when acute appendicitis was suspected. Therefore, the clinical efficacy of Tc-99m HMPAO labeled leukocyte (TC-WBC) scan for the diagnosis of acute appendicitis in patients presenting with atypical clinical findings is assessed. Patients and Methods: Eighty patients presenting with acute abdominal pain and possible acute appendicitis but atypical findings were included in this study. After intravenous injection of TC-WBC, serial anterior abdominal/pelvic images at 30, 60, 120 and 240 min with 800k counts were obtained with a gamma camera. Any abnormal localization of radioactivity in the right lower quadrant of the abdomen, equal to or greater than bone marrow activity, was considered as a positive scan. Results: 36 out of 49 patients showing positive TC-WBC scans received appendectomy. They all proved to have positive pathological findings. Five positive TC-WBC were not related to acute appendicitis, because of other pathological lesions. Eight patients were not operated and clinical follow-up after one month revealed no acute abdominal condition. Three of 31 patients with negative TC-WBC scans received appendectomy. They also presented positive pathological findings. The remaining 28 patients did not receive operations and revealed no evidence of appendicitis after at least one month of follow-up. The overall sensitivity, specificity, accuracy, positive and negative predictive values for TC-WBC scan to diagnose acute appendicitis were 92, 78, 86, 82, and 90%, respectively. Conclusion: TC-WBC scan provides a rapid and highly accurate method for the diagnosis of acute appendicitis in patients with equivocal clinical examination. It proved useful in reducing the false-positive rate of laparotomy and shortens the time necessary for clinical observation.

Predicting Fetal Chromosome Anomalies in the First Trimester Using Pregnancy Associated Plasma Protein-A: A Comparison of Statistical Methods

1993 ◽  
Vol 32 (02) ◽  
pp. 175-179 ◽  
Author(s):  
B. Brambati ◽  
T. Chard ◽  
J. G. Grudzinskas ◽  
M. C. M. Macintosh
Keyword(s):  
Logistic Regression ◽  
General Population ◽  
Likelihood Ratio ◽  
False Positive ◽  
False Positive Rate ◽  
Ratio Method ◽  
Detection Rates ◽  
Gaussian Distributions ◽  
Positive Rate ◽  
Likelihood Ratio Method

Abstract:The analysis of the clinical efficiency of a biochemical parameter in the prediction of chromosome anomalies is described, using a database of 475 cases including 30 abnormalities. A comparison was made of two different approaches to the statistical analysis: the use of Gaussian frequency distributions and likelihood ratios, and logistic regression. Both methods computed that for a 5% false-positive rate approximately 60% of anomalies are detected on the basis of maternal age and serum PAPP-A. The logistic regression analysis is appropriate where the outcome variable (chromosome anomaly) is binary and the detection rates refer to the original data only. The likelihood ratio method is used to predict the outcome in the general population. The latter method depends on the data or some transformation of the data fitting a known frequency distribution (Gaussian in this case). The precision of the predicted detection rates is limited by the small sample of abnormals (30 cases). Varying the means and standard deviations (to the limits of their 95% confidence intervals) of the fitted log Gaussian distributions resulted in a detection rate varying between 42% and 79% for a 5% false-positive rate. Thus, although the likelihood ratio method is potentially the better method in determining the usefulness of a test in the general population, larger numbers of abnormal cases are required to stabilise the means and standard deviations of the fitted log Gaussian distributions.

Identification of and Correction for Publication Bias: Comment

2019 ◽  
Author(s):  
Amanda Kvarven ◽  
Eirik Strømland ◽  
Magnus Johannesson
Keyword(s):  
Publication Bias ◽  
False Positive ◽  
Large Scale ◽  
Meta Analysis ◽  
False Positive Rate ◽  
Effect Sizes ◽  
Replication Studies ◽  
Moderate Reduction ◽  
Positive Rate ◽  
Meta Analyses

Andrews & Kasy (2019) propose an approach for adjusting effect sizes in meta-analysis for publication bias. We use the Andrews-Kasy estimator to adjust the result of 15 meta-analyses and compare the adjusted results to 15 large-scale multiple labs replication studies estimating the same effects. The pre-registered replications provide precisely estimated effect sizes, which do not suffer from publication bias. The Andrews-Kasy approach leads to a moderate reduction of the inflated effect sizes in the meta-analyses. However, the approach still overestimates effect sizes by a factor of about two or more and has an estimated false positive rate of between 57% and 100%.

scholarly journals PRATD: A Phased Remote Access Trojan Detection Method with Double-Sided Features

Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1894
Author(s):  
Chun Guo ◽  
Zihua Song ◽  
Yuan Ping ◽  
Guowei Shen ◽  
Yuhei Cui ◽  
...  
Keyword(s):  
False Positive ◽  
Detection Method ◽  
False Positive Rate ◽  
True Positive Rate ◽  
Remote Access ◽  
Detection Methods ◽  
Security Threats ◽  
True Positive ◽  
Trojan Detection ◽  
Positive Rate

Remote Access Trojan (RAT) is one of the most terrible security threats that organizations face today. At present, two major RAT detection methods are host-based and network-based detection methods. To complement one another’s strengths, this article proposes a phased RATs detection method by combining double-side features (PRATD). In PRATD, both host-side and network-side features are combined to build detection models, which is conducive to distinguishing the RATs from benign programs because that the RATs not only generate traffic on the network but also leave traces on the host at run time. Besides, PRATD trains two different detection models for the two runtime states of RATs for improving the True Positive Rate (TPR). The experiments on the network and host records collected from five kinds of benign programs and 20 famous RATs show that PRATD can effectively detect RATs, it can achieve a TPR as high as 93.609% with a False Positive Rate (FPR) as low as 0.407% for the known RATs, a TPR 81.928% and FPR 0.185% for the unknown RATs, which suggests it is a competitive candidate for RAT detection.

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