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Immunopathogenesis and Therapy of Gonadal Disorders and Infertility
Published in George S. Eisenbarth, Immunotherapy of Diabetes and Selected Autoimmune Diseases, 2019
A large number of different assays have been developed to detect antisperm antibodies. This has led to controversy regarding the most useful test and comparability of the published studies. The agglutination assays have several problems. A high false positive rate can occur. Nonspecific sperm agglutination may occur (due to β2 macroglobulin in some specimens). Several assays have been developed including the gelatin agglutination test (GAT) in test tubes (read on a macroscopic level), and the microtest. The potential advantage of the microtest (tray agglutination test, TAT) lies in its ability to determine the type of agglutination reaction (head to head, tail to tail, etc.). Blood group antigens do not appear to play a role in this test. The agglutination reaction does not occur when antigen is in excess.58-60
The Basics of Statistical Analysis
Published in Henry George Adams, Sudhir Arora, Total Quality in Radiology, 2018
Henry George Adams, Sudhir Arora
The measurable values in assessing exam pre-test capability are as follows. Sensitivity (also known as pre-test true positive rate): TP/(TP + FN). The likelihood of obtaining a positive test in a patient with disease.Specificity (also known as pre-test true negative rate): TN/(TN + FP). The likelihood of obtaining a negative test in a patient without disease.Pre-test false-negative rate (1 − sensitivity): The likelihood of obtaining a negative test in a patient with disease.Pre-test false positive rate (1 − specificity): The likelihood of obtaining a positive test in a patient without disease.
Basket Trials at the Confirmatory Stage
Published in Zoran Antonijevic, Robert A. Beckman, Platform Trial Designs in Drug Development, 2018
We have outlined a general histology agnostic “basket study” that can enable grouping and simultaneous development of a therapy in multiple indications with a common predictive biomarker hypothesis. Such a design entails screening and removal of indications of lower likelihood to succeed based on maturing external data and on internal surrogate data or interim definitive endpoint data, the possibility of individual accelerated approval of indications based on an approved surrogate endpoint or on interim definitive endpoint data, pooling of the definitive endpoint across indications for approval, and the demand for a favorable numerical trend in the definitive endpoint in each approved indication. In contrast to previous designs, this design incorporates the rigor of concurrent control groups and control of the false positive rate under the assumption of all indications being ineffective. Thus this design may be suitable for confirmatory studies of effective therapies without requiring that they be transformational. Attention must be paid to the selection of indications and to the risk of diluting positive indications with negative ones in the pooled analysis, to protect the validity of the conclusions. Generalized control of the false positive rate is an area of ongoing research.
Adherence to referrals from preschool vision screening and identification of barriers for non-adherence in Israel
Published in Clinical and Experimental Optometry, 2023
Ariela Gordon-Shaag, Hadas Ben-Eli, Orit Sztrigler Cohen, Monique Toledano, Aviya Benyamin, Chen Stein-Zamir
Alternatively, the high false-positive rate in the current study may be the result of over-referral. Indeed, the students may not have had the skills to examine young children which may have resulted in 3% of the children being referred for non-compliance. These children may have complied with a more experienced practitioner. In any screening program, there is a trade-off between sensitivity and specificity.40 In a large community wide preschool vision screening program, when the diagnostic procedure is non-invasive (eye examination), and the consequence of false-negatives could be amblyopia, a low sensitivity may be an acceptable price to pay for high specificity. However, since the current study was not designed to test sensitivity and specificity, this cannot be assessed. Therefore, further research must be conducted to determine the factors that led to the high false-positive rate.
Effective heart disease prediction with Grey-wolf with Firefly algorithm-differential evolution (GF-DE) for feature selection and weighted ANN classification
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
The following research gaps are identified from the above related works performed in this study are,Specific optimization models ought to be extended to handle shorter heart-beat signals and long-duration heartbeat signals.The conventional methodologies demand the process of the pre-processing of signals, detections of waveforms, feature-extraction process and the utilization of hand-crafted features for the classification techniques. Hence while in the implementation of these modules, the systems may produce a false-positive rate. This false-positive rate would lead to misdiagnosis process and irrelevant therapies.Some researchers have been justified their proposed model with minimum comparison and thus several effective comparative analysis is required.The processing power consumption of the predictive learning system, the computational time of the implementation would have a dependency on carrying out the feature-selection along with classification models.
Point of care molecular and antigen detection tests for COVID-19: current status and future prospects
Published in Expert Review of Molecular Diagnostics, 2022
William Stokes, Byron M. Berenger, Allison A. Venner, Vincent Deslandes, Julie L. V. Shaw
The validation of RATs for asymptomatic screening requires large studies that must consider the prevalence of disease in the population tested. A lower PPV is expected when prevalence is low. One study found a RAT PPV of 0.12% in a low prevalence population [41]. A large Canadian study (71,849 RAT) looked at the performance of two RATs (Abbott Panbio and BD Veritor (Becton Dickinson, NJ, USA)) for asymptomatic screening of healthcare workers at continuing care sites and found a high false-positive rate (30% or 70% positives were false, respectively) [42] . A high false positive rate can have several negative impacts, such as anxiety, loss of income or staff shortages. False-positive results can be minimized by following the manufacturer’s instructions for use, and by minimizing cross-contamination by working in a clean environment [43]. The PPV will also be higher in populations with higher disease prevalence [44]. Another Canadian study assessed the performance of the Abbott Panbio RAT for asymptomatic screening of ~3000 healthcare workers in long-term care homes, and found an NPV of 99.8%, which was a minimal improvement over the NPV based on pretest probability alone (99.6%) [45]. Only 14 positive individuals were identified in this study by PCR, with no false positives by RAT. All tests were performed by trained lab technologists or by healthcare professionals trained by the laboratory.