scholarly journals P07.05: Using nasal bone as a marker is associated with lower false-positive rate in sonographic screening of trisomy 21 at Hospital Sonderjylland Sonderborg

2012 ◽  
Vol 40 (S1) ◽  
pp. 194-194
Author(s):  
R. Andreassen ◽  
L. Brendstrup ◽  
D. Schmidt ◽  
M. Bojsen ◽  
K. Sievertsen ◽  
...  
Keyword(s):  
False Positive ◽  
Trisomy 21 ◽  
False Positive Rate ◽  
Nasal Bone ◽  
Lower False Positive Rate ◽  
Positive Rate ◽  
Sonographic Screening

Abstract 17015: When is a Pathological Q Wave Truly Pathological?

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Keerthi Prakash ◽  
Aneil Malhotra ◽  
Harshil Dhutia ◽  
Philippe Siegenthaler ◽  
Grant Nolan ◽  
...  
Keyword(s):  
False Positive ◽  
Comprehensive Evaluation ◽  
False Positive Rate ◽  
Young Athletes ◽  
Entire Cohort ◽  
Lower False Positive Rate ◽  
Positive Rate ◽  
Cardiac Evaluation ◽  
Health And Disease ◽  
Q Wave

Introduction: Pathological Q waves are considered harbingers of cardiac pathology and should instigate comprehensive evaluation of athletes. Several definitions of the depth or duration of a Q wave exist, with disagreement between scientific bodies as to the most useful. Objectives: 1. Determine the prevalence of pathological Q waves in large cohorts of the general population, athletes and patients with hypertrophic cardiomyopathy (HCM). 2. Identify the most accurate Q wave criterion. Methods: ECGs were retrospectively analysed in consecutive cohorts of 10,008 healthy young athletes (14-35 years old), 2,994 healthy young non-athletes and 468 HCM patients. Results: Pathological Q waves that fulfilled at least one of the 4 individual definitions (Table 1) were identified in 0.7% athletes (n = 75), 1.2% non-athletes (n = 36) and 22.6% patients with HCM (n = 106). In the healthy athletic and non-athletic population, all pathological Q waves (n = 111) met the >3mm depth definition. In contrast, the majority of pathological Q waves in HCM patients met the ≥40msec duration definition (n = 75; 70.75%). We tested the ability of all 4 criteria to distinguish between health and disease in the entire cohort. Seattle and Refined had the best sensitivity for detecting HCM. Refined criteria however, had a significantly higher positive predictive value and 7 times lower false positive rate compared to Seattle. (Table 2) Conclusion: Pathological Q waves are present in up to 1.2% of healthy young individuals and do not correlate with physical activity. Of the proposed criteria, the Refined criteria has the lowest false positive rate and should be utilised in the context of cardiac evaluation in young athletes.

Needle EMG has a lower false positive rate than MRI in asymptomatic older adults being evaluated for lumbar spinal stenosis

2007 ◽  
Vol 118 (4) ◽  
pp. 751-756 ◽  
Author(s):  
Anthony Chiodo ◽  
Andrew J. Haig ◽  
Karen S.J. Yamakawa ◽  
Douglas Quint ◽  
Henry Tong ◽  
...  
Keyword(s):  
Older Adults ◽  
Spinal Stenosis ◽  
Lumbar Spinal Stenosis ◽  
False Positive ◽  
False Positive Rate ◽  
Lower False Positive Rate ◽  
Positive Rate ◽  
Lumbar Spinal

scholarly journals First Trimester Genetic Sonogram for Screening Fetal Down Syndrome: a Population-based Study

2020 ◽  
Author(s):  
Kuntharee Traisrisilp ◽  
Supatra Sirichotiyakul ◽  
Fuanglada Tongprasert ◽  
Kasemsri Srisupun ◽  
Suchaya Luewan ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Pregnant Women ◽  
False Positive ◽  
Detection Rate ◽  
False Positive Rate ◽  
Nasal Bone ◽  
First Trimester ◽  
Nuchal Translucency ◽  
Ductus Venosus ◽  
Positive Rate

Abstract Background: To evaluate the performance of first trimester sonomarkers in the detection of fetal Down syndrome among Thai pregnant womenMethods: Pregnant women at 11-13+6 weeks’ gestation underwent ultrasound examination for assessment of nuchal translucency (NT), nasal bone (NB), tricuspid regurgitation (TR), and abnormal ductus venosus (aDV) Doppler waveforms. The women were followed up for final outcomes. Fetal abnormalities other than trisomy 21 were excluded. The performances of each sonomarker and their combinations in predicting fetal Down syndrome were calculated.Results: A total of 7,820 pregnant women meeting the inclusion criteria were available for analysis, including 20 cases with fetal Down syndrome and 7,800 unaffected cases. Of the four sonomarkers, NT, as a single sonomarker, had the highest detection rate (55.0% at a false positive rate of about 5%), whereas the remaining single sonomarkers had low detection rate (15-20%). The combination of all sonomarkers had the highest detection rate of 70% but the false positive rate was as high as 10.8%. The combination of NT and NB had a detection rate of 60% with an acceptable false positive rate of 6.9%, whereas the other combinations yielded relatively high false positive rates. Conclusion: The first trimester genetic sonogram in screening for Down syndrome among Asian women is acceptably effective and may be offered to some selected groups of the population. NT is the best sonomarker with a detection rate of 55% at 5% false positive rate and its combination with NB can improve performance with minimal increase in false positive rate.

AN EVALUATION OF EPA SHEEN TESTS FOR DRILLING FLUID DISCHARGE1

1987 ◽  
Vol 1987 (1) ◽  
pp. 521-528 ◽  
Author(s):  
Maurice Jones ◽  
Gordon H. Otto
Keyword(s):  
Environmental Protection Agency ◽  
False Positive ◽  
Drilling Fluid ◽  
False Positive Rate ◽  
Test Procedures ◽  
Lower False Positive Rate ◽  
Positive Rate ◽  
Series Of Experiments ◽  
Pollutant Discharge ◽  
New Procedures

ABSTRACT The U.S. Environmental Protection Agency (EPA) has prohibited the discharge of “free oil” in offshore drilling discharges and proposed new procedures to detect such oil. A statistically designed series of experiments was performed to evaluate three proposed sheen test procedures: EPA's Gulf of Mexico, Alaska, and cup protocols. Seventy-four independent observers conducted over 6,360 sheen tests. The experiments evaluated the effects of freshwater and saltwater test media, two lighting types, two mud types, and two oil types (diesel and mineral) at five concentrations (including a blank). The cup and Gulf tests had relatively high false positive rates. The Alaska procedure had a lower false positive rate, but did not detect oil concentrations of 5% reliably under some test conditions. As a result, none of the three procedures used can be considered satsifactory for National Pollutant Discharge Elimination System permit compliance.

scholarly journals Screening for aneuploidies by maternal age, fetal nuchal translucency and maternal serum biochemistry at 11-13+6 gestational weeks

2012 ◽  
Vol 140 (9-10) ◽  
pp. 606-611 ◽  
Author(s):  
Natasa Karadzov-Orlic ◽  
Amira Egic ◽  
Dejan Filimonovic ◽  
Maja Marinkovic ◽  
Barbara Damnjanovic-Pazin ◽  
...  
Keyword(s):  
False Positive ◽  
Trisomy 21 ◽  
Maternal Age ◽  
False Positive Rate ◽  
First Trimester ◽  
Nuchal Translucency ◽  
Maternal Serum ◽  
Trisomy 18 ◽  
Serum Free ◽  
Positive Rate

Introduction. Aneuploidies are the major cause of perinatal death and early psychophysical disorders. Objective. In this study, we analyzed detection and false-positive rates of screening for aneuploidies in the first trimester by the combination of maternal age, fetal nuchal translucency (NT) thickness and maternal serum free beta-human chorionic gonadotrophin (?-hCG), and pregnancy-associated plasma protein-A (PAPP-A) at 11-13+6 weeks of gestation, using the appropriate software developed by the Fetal Medicine Foundation. Methods. Our screening study for aneuploidies analyzed 4172 singleton pregnancies from January 2006 to December 2010. The sensitivities and false-positive rates using the combined aneuploidies determination for the risk cut-off of 1:275 were evaluated. Results. In the trisomy 21 pregnancies, the fetal NT was higher than 95th centile, in 72.8%, serum free b-hCG concentration it was above the 95th centile in 55% and serum PAPP-A was below the 5th centile in 47% of the cases. In the trisomy 18 and 13, the fetal NT was above 95th centile in 66.6% and 44.4% of the cases, respectively. The serum free b-hCG concentration was above the 95th centile in 0 and 10%, but serum PAPP-A was below 5th centile in 80.9% and 88.8% of pregnancies. In the trisomy 21 pregnancies the median free beta-hCG was 2.3 MoM and the median PAPP-A was 0.45 MoM. Chromosomal abnormalities were detected in 169 fetuses: trisomy 21 (97), Turner syndrome (19), trisomy 18 (28), trisomy 13 (11) and others (14). Detection rate of combined screening for aneuploides were 86.0% with false positive rate of 5.3% (mean age 33?4.9 years, >35 years in 35% of pregnancies). Conclusion. Our study suggests that the strategy of first-trimester combined screening of biochemical values and ultrasonographic parameters at 12 gestational weeks identifies higher percentage of aneuploidies with a lower false-positive rate than a single parameter strategy.

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%.

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