scholarly journals Postoperative Troponin Measurement as a Screening Tool for Adverse Cardiac Events in Adult Patients Undergoing Moderate Or Major Non-Cardiac Surgery

2017 ◽  
Vol 45 (6) ◽  
pp. 683-687
Author(s):  
D. Coric ◽  
N. A. Smith
Keyword(s):  
Cardiac Surgery ◽  
False Positive ◽  
Screening Tool ◽  
False Positive Rate ◽  
Routine Practice ◽  
Cardiac Events ◽  
Tertiary Referral Hospital ◽  
Increased Risk ◽  
Adverse Cardiac Events ◽  
Positive Rate

Elevated troponin levels within three days of surgery are strongly linked to major adverse cardiac events (MACE). However the value of screening with troponin measurements is controversial. The extent to which this is done in routine practice is uncertain. We examined the medical records of all patients ≥45 years of age undergoing moderate or major non-cardiac surgery in our tertiary referral hospital over a six-month period. We determined how many patients had a troponin (TnT) measurement recorded in the first three days postoperatively, how many of these were abnormal, and the occurrence of MACE within 30 days. Two thousand and two hundred patients underwent 2,577 operations that met the study criteria. A postoperative TnT was measured after 4.5% of operations. Thirty-eight percent of patients with a recorded TnT measurement, and 44% of those with an abnormal measurement, experienced a MACE within 30 days. The sensitivity of an abnormal TnT to detect MACE was 86%. The specificity was low at 32% with a false positive rate of 56%. Patients with an abnormal TnT result had an increased risk of MACE (23%). The ‘number needed to measure’ to detect one patient with MACE was 4.4. In our institution, postoperative TnT levels were rarely measured and were used as a diagnostic rather than as a screening tool. The high false positive rate for MACE prediction limits its potential value as a screening tool. The test could be considered useful if it leads to further investigation, and may be best considered as one component of a multivariate approach to cardiac risk evaluation and diagnosis.

scholarly journals Utilizing two-tiered screening for early detection of autism spectrum disorder

Autism ◽  
2017 ◽  
Vol 22 (7) ◽  
pp. 881-890 ◽  
Author(s):  
Meena Khowaja ◽  
Diana L Robins ◽  
Lauren B Adamson
Keyword(s):  
Early Detection ◽  
Young Children ◽  
False Positive ◽  
Screening Tool ◽  
False Positive Rate ◽  
Autism Spectrum ◽  
Screening Methods ◽  
Positive Rate ◽  
Level 1 ◽  
Level 2

Despite advances in autism screening practices, challenges persist, including barriers to implementing universal screening in primary care and difficulty accessing services. The high false positive rate of Level 1 screening methods presents especially daunting difficulties because it increases the need for comprehensive autism evaluations. This study explored whether two-tiered screening—combining Level 1 (Modified Checklist for Autism in Toddlers, Revised with Follow-Up) and Level 2 (Screening Tool for Autism in Toddlers and Young Children) measures—improves the early detection of autism. This study examined a sample of 109 toddlers who screened positive on Level 1 screening and completed a Level 2 screening measure prior to a diagnostic evaluation. Results indicated that two-tiered screening reduced the false positive rate using published Screening Tool for Autism in Toddlers and Young Children cutoffs compared to Level 1 screening alone, although at a cost to sensitivity. However, alternative Screening Tool for Autism in Toddlers and Young Children scoring in the two-tiered screening improved both positive predictive value and sensitivity. Exploratory analyses were conducted, including comparison of autism symptoms and clinical profiles across screening subsamples. Recommendations regarding clinical implications of two-tiered screening and future areas of research are presented.

Impact of Including or Removing Nuchal Translucency Measurement on the Detection and False-Positive Rates of First-Trimester Down Syndrome Screening

2015 ◽  
Vol 40 (3) ◽  
pp. 214-218 ◽  
Author(s):  
Emmanuel Spaggiari ◽  
Isabelle Czerkiewicz ◽  
Corinne Sault ◽  
Sophie Dreux ◽  
Armelle Galland ◽  
...  
Keyword(s):  
Down Syndrome ◽  
False Positive ◽  
False Positive Rate ◽  
Method Comparison ◽  
First Trimester ◽  
Nuchal Translucency ◽  
Routine Practice ◽  
Detection Rates ◽  
Significant Difference ◽  
Positive Rate

Introduction: First-trimester Down syndrome (DS) screening combining maternal age, serum markers (pregnancy-associated plasma protein-A and beta-human chorionic gonadotropin) and nuchal translucency (NT) gives an 85% detection rate for a 5% false-positive rate. These results largely depend on quality assessment of biochemical markers and of NT. In routine practice, despite an ultrasound quality control organization, NT images can be considered inadequate. The aim of the study was to evaluate the consequences for risk calculation when NT measurement is not taken into account. Material and Method: Comparison of detection and false-positive rates of first-trimester DS screening (PerkinElmer, Turku, Finland), with and without NT, based on a retrospective study of 117,126 patients including 274 trisomy 21-affected fetuses. NT was measured by more than 3,000 certified sonographers. Results: There was no significant difference in detection rates between the two strategies including or excluding NT measurement (86.7 vs. 81.8%). However, there was a significant difference in the false-positive rates (2.23 vs. 9.97%, p < 0.001). Discussion: Sonographers should be aware that removing NT from combined first-trimester screening would result in a 5-fold increase in false-positive rate to maintain the expected detection rates. This should be an incentive for maintaining quality in NT measurement.

scholarly journals SARS-CoV-2 immunochromatographic IgM/IgG rapid test in pregnancy: A false friend?

2020 ◽  
pp. 000456322098049
Author(s):  
M Fabre ◽  
S Ruiz-Martinez ◽  
ME Monserrat Cantera ◽  
A Cortizo Garrido ◽  
Z Beunza Fabra ◽  
...  
Keyword(s):  
Positive Predictive Value ◽  
Pregnant Women ◽  
Predictive Value ◽  
False Positive ◽  
Screening Tool ◽  
False Positive Rate ◽  
Rapid Test ◽  
Immunochromatographic Assay ◽  
Qualitative Detection ◽  
Positive Rate

Background An increasing body of evidence has revealed that SARS-CoV-2 infection in pregnant women could increase the risk of adverse maternal and fetal outcomes. Careful monitoring of pregnancies with COVID-19 and measures to prevent neonatal infection are warranted. Therefore, rapid antibody tests have been suggested as an efficient screening tool during pregnancy. Cases We analysed the clinical performance during pregnancy of a rapid, lateral-flow immunochromatographic assay for qualitative detection of SARS-CoV-2 IgG/IgM antibodies. We performed a universal screening including 169 patients during their last trimester of pregnancy. We present a series of 14 patients with positive SARS-CoV-2 immunochromatographic assay rapid test result. Immunochromatographic assay results were always confirmed by chemiluminescent microparticle immunoassays for quantitative detection of SARS-CoV-2 IgG and IgM+IgA antibodies as the gold standard. We observed a positive predictive value of 50% and a false positive rate of 50% in pregnant women, involving a significantly lower diagnostic performance than reported in non-pregnant patients. Discussion Our data suggest that although immunochromatographic assay rapid tests may be a fast and profitable screening tool for SARS-CoV-2 infection, they may have a high false positive rate and low positive predictive value in pregnant women. Therefore, immunochromatographic assay for qualitative detection of SARS-CoV-2 IgG/IgM antibodies must be verified by other test in pregnant patients.

Altered Recognition of Reparative Changes in ThinPrep Specimens in the College of American Pathologists Gynecologic Cytology Program

2005 ◽  
Vol 129 (7) ◽  
pp. 861-865 ◽  
Author(s):  
Tamela M. Snyder ◽  
Andrew A. Renshaw ◽  
Patricia E. Styer ◽  
Dina R. Mody ◽  
Terence J. Colgan
Keyword(s):  
Error Rate ◽  
False Positive ◽  
Interlaboratory Comparison ◽  
False Positive Rate ◽  
Performance Criteria ◽  
Exact Match ◽  
Increased Risk ◽  
Positive Rate ◽  
Characteristic Features ◽  
Reparative Changes

Abstract Context.—Previous studies have shown that the diagnosis of reparative changes in conventional smears in the College of American Pathologists Interlaboratory Comparison Program in Gynecologic Cytology is one of the least reproducible diagnoses. Indeed, the diagnosis of reparative changes consistently yields the highest false-positive rate of any negative for intraepithelial lesions and malignancy (NILM) cytodiagnostic category. It is unknown whether cytologists recognize reparative changes in ThinPrep specimens as well, or less often, as in conventional smears. Objective.—To assess and compare the ability of cytologists to recognize reparative changes in conventional and ThinPrep preparations. Design.—We compiled performance data from the College of American Pathologists Interlaboratory Comparison Program in Gynecologic Cytology from the 2000–2003 program years. More than 400 slides with a reference diagnosis of reparative changes met our study criteria, representing a total of 11 200 individual responses for conventional cases and 1155 individual responses for ThinPrep specimens. We evaluated the results of both individual and laboratory participants using 2 performance criteria: the false-positive discordancy rate and the exact match error rate (any response that does not exactly match the reference diagnosis of 120 [reparative changes]). Results.—Cases with a reference diagnosis of reparative changes made up 1.2% of all ThinPrep slides and 3.7% of all conventional slides in circulation. The false-positive discordancy rate of individual responses on educational slides for conventional smears was significantly higher than the corresponding false-positive discordancy rate for ThinPrep specimens (15.7% for conventional vs 7.1% for ThinPrep specimens, P &lt; .001). Laboratory responses on educational conventional smears and ThinPrep slides showed a similar trend (14.2% for conventional smears vs 2.4% for ThinPrep slides, P = .002). The exact match error rate on educational conventional slides was 41.4% for individual responses, while on educational ThinPrep slides, the overall error rate was 57.5% (P &lt; .001). For laboratory responses, the exact match error rate was 40.5% for educational conventional smears versus 58.9% for educational ThinPrep smears (P &lt; .001). Characteristic features of reparative changes were identified in ThinPrep specimens. Conclusions.—In the College of American Pathologists Interlaboratory Comparison Program in Gynecologic Cytology, ThinPrep slides with a reference diagnosis of reparative changes have a lower false-positive discordancy rate than conventional slides. Responses to ThinPrep cases with a reference diagnosis of reparative change show a higher exact match error rate than conventional smears. Since reparative changes in gynecologic cytology are recognized as indicating an increased risk of significant lesions, the clinical significance of these altered patterns of recognition of reparative changes in ThinPrep specimens warrants further investigation.

scholarly journals 083 Novel wireless S – patch device may efficiently detect atrial fibrillation in patients with ischaemic stroke

2019 ◽  
Vol 90 (e7) ◽  
pp. A26.3-A27 ◽  
Author(s):  
Suzana Lazarovska ◽  
Hui Tie ◽  
Andrew Hopkins ◽  
Hany Dimitri ◽  
Upul Premawardhana ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
False Positive ◽  
Detection Rate ◽  
False Positive Rate ◽  
Case Series ◽  
Time Saving ◽  
Novel Device ◽  
Increased Risk ◽  
Positive Rate ◽  
Prospective Case Series

IntroductionAtrial fibrillation (AF) is the most common atrial arrhythmia leading to increased risk of thromboembolic events. Ward telemetry (WT) has a low detection rate for AF in stroke patients and often patients are not appropriately treated with anticoagulation. This study compares conventional 2-day WT versus 4-day wireless S-patch monitoring to detect AF.MethodsProspective case series.Results51 patients admitted for stroke workup were recruited across 2 major tertiary centre’s in Sydney to compare WT monitoring for 2 days versus S-patch monitoring for 4 days in the detection of AF. The efficacy to detect AF using both technologies across 76 hours of telemetry was assessed via data extractions and Cardiologist review. A matrix was used to measure nursing/patient satisfaction and setup/resource times were assessed.84–94% of patients and 75–95% of nursing preferred the S-Patch. Non-parametric tests indicate significant time saving for removal of S-Patch versus WT [2.2 mins vs 5.1 mins (p=0.00)]. Efficacy of S-Patch to detect AF following Cardiologist review was greater than WT, with 7 patients identified with AF by S-Patch versus 1 using WT. The S-patch had a false positive rate of 78%.ConclusionThe S-patch had a higher detection rate of AF compared to WT. This allows patients to be anticoagulated appropriately for the prevention of further stroke. Analysis shows patients and staff overwhelmingly prefer the S-Patch. The S-Patch is sensitive in the detection of AF however it showed a high false positive rate. We are confident that further refinement and advances will provide a novel device in the detection of AF.

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 &amp; 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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