scholarly journals Secondary Analysis on Malaria RDTs in WHO Product Testing from Round 5 to 8 on False Negative Results in Testing Sample

2021 ◽  
Author(s):  
Biao Xu ◽  
Bo Tu ◽  
Fang Chu ◽  
Mohamed Jalloh ◽  
Jinsong Mu ◽  
...  
Keyword(s):  
Parasite Density ◽  
Storage Temperature ◽  
False Negative ◽  
Secondary Analysis ◽  
False Negative Rate ◽  
Product Testing ◽  
Weak Band ◽  
Negative Results ◽  
Malaria Rdts ◽  
False Negative Results

Abstract Background with the widespread use of malaria rapid diagnostic tests (RDTs) in clinical practice, they also show their own challenges. Compared with most of the attention focusing on false positive results in WHO product testing, the same important false negative results attract insufficient focus. Method data of 129 malaria RDTs in the summary of WHO rounds 5 to 8 product testing was secondary analyzed in 5 aspects including low parasite density, improper RDTs storage, operation and interpretation, P. falciparum (Pf) with pfhrp2/3 genes deletion, inter-lot variation. Results First, the percentage of tests that achieved a panel detection score (PDS) < 80% at a low parasite density was 20-25% for Pf, and substantially higher for P. vivax (Pv). Second, Some Pv- and Pf- detecting products showed an increasing deterioration with increase of storage temperature. Third, approximately 20-27% products’ performances were unsatisfied in blood safety and instruction quality; and 30-35% test bands of the RDTs for Pf were barely visible, and the ones for Pv returned a higher proportion of weak band intensity. Fourth, different Lots of each test products may produce inconsistent results. Fifth, many malaria RDTs obtained a low PDS (< 50%) and a high false negative rate (> 50%) when testing Pf with deletion of pfhrp2/3 gene. Conclusion the malaria RDTs currently widely used were overestimated and could cause false negative results in practice. The clinicians should be aware of these shortcomings in order to draw more accurate diagnosis and treatment.

scholarly journals Secondary analysis of malaria rapid diagnostic tests from rounds 5–8 of WHO product testing with a focus on false-negative results

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Biao Xu ◽  
Bo Tu ◽  
Fang Chu ◽  
Mohamed Jalloh ◽  
Jin-Song Mu ◽  
...  
Keyword(s):  
Gene Deletion ◽  
False Negative ◽  
Secondary Analysis ◽  
World Health ◽  
Product Testing ◽  
Negative Results ◽  
Malaria Rdts ◽  
False Negative Results ◽  
Malaria Rapid Diagnostic Tests ◽  
Health Organization

AbstractDespite the widespread use of malaria rapid diagnostic test (RDT) in clinical practice, there are a lot of challenges. We conducted a secondary analysis of 129 malaria RDT data from rounds 5–8 of the World Health Organization (WHO) product testing summary and discuss the causes of false-negative (FN) results with a focus on low parasite density, improper RDT storage, operation and interpretation, and plasmodium falciparum with a pfhrp2/3 gene deletion. The results demonstrated that the malaria RDTs currently commercially available might cause FN results in practice.

scholarly journals Evaluation of risk factors for false-negative results with an antigen-specific peripheral blood-based quantitative T cell assay (T-SPOT®.TB) in the diagnosis of active tuberculosis: A large-scale retrospective study in China

2018 ◽  
Vol 46 (5) ◽  
pp. 1815-1825 ◽  
Author(s):  
Chi Yang ◽  
Shaojun Zhang ◽  
Lan Yao ◽  
Lin Fan
Keyword(s):  
Risk Factors ◽  
Retrospective Study ◽  
Respiratory Diseases ◽  
False Negative ◽  
False Negative Rate ◽  
Active Tuberculosis ◽  
Pulmonary Tb ◽  
Negative Results ◽  
False Negative Results ◽  
Negative Sputum

Objective To investigate the diagnostic efficacy of an interferon-γ release assay, T-SPOT®. TB, for diagnosing active tuberculosis (TB) and to identify risk factors for false-negative results. Methods This retrospective study enrolled consecutive patients with active TB and with non-TB respiratory diseases to evaluate the risk factors for false-negative results when using the T-SPOT®. TB assay for the diagnosis of active TB. Patients with active TB were categorized as having confirmed pulmonary TB, clinically diagnosed pulmonary TB or extrapulmonary TB (EPTB). Results This study analysed 4964 consecutive patients; 2425 with active TB and 2539 with non-TB respiratory diseases. Multivariate logistic regression analyses identified the following five factors that were all associated with an increased false-negative rate with the T-SPOT®. TB assay: increased age (odds ratio [OR] 1.018; 95% confidence interval [CI] 1.013, 1.024); decreased CD8+ count (OR 0.307; 95% CI 0.117, 0.803); negative sputum acid-fast bacilli (AFB) smear staining (OR 1.821; 95% CI 1.338, 2.477); negative mycobacterial cultures (OR 1.379; 95% CI 1.043, 1.824); and absence of EPTB (OR 1.291; 95% CI 1.026, 1.623). Conclusions Increased age, decreased CD8+ count, negative sputum AFB smear results, negative sputum mycobacterial cultures and absence of EPTB might lead to an increased false-negative rate when using the T-SPOT®. TB assay.

scholarly journals Distal Measurements Can Produce False Negative Results: A Prospective Secondary Analysis of a Natural History Study

2018 ◽  
Vol 21 (12) ◽  
pp. 1727-1730
Author(s):  
Elias M Klemperer ◽  
John R Hughes ◽  
Shelly Naud
Keyword(s):  
Natural History ◽  
False Negative ◽  
Secondary Analysis ◽  
Absolute Magnitude ◽  
Percent Reduction ◽  
Natural History Study ◽  
Negative Results ◽  
False Negative Results ◽  
Quit Attempts ◽  
Proximal Analysis

Abstract Introduction Most prospective studies of quit attempts (QAs) or abstinence measure the ability of variables to predict quitting many weeks or months later. This design ignores more proximal fluctuations in the predictor that may be more relevant. The present secondary analysis compares 6-week (distal) and daily (proximal) changes in cigarettes per day (CPD) as predictors of making a QA. Methods Daily smokers reported CPD and QAs nightly throughout a 12-week natural history study. We provided no treatment. In the distal analysis, we tested whether reduction in CPD between baseline and 6 weeks predicted making a QA during the following 6 weeks. In the proximal analysis, we identified episodes of one or more days of ≥10% reduction in CPD and tested whether reduction predicted making a QA on the day immediately after the reduction episode. We tested the following predictors: (1) reduction in CPD of ≥10% (yes/no), (2) percent reduction, (3) absolute magnitude of reduction, and (4) CPD at the end of reduction. Results In the distal analysis, reduction did not predict making a QA. In the proximal analysis, any reduction (OR = 3.0), greater percent reduction (OR = 1.6), greater absolute reduction (OR = 1.3), and fewer CPD on the final day of an episode (OR = 11.8) predicted making a QA the next day (all p &lt; .001). Discussion Relying on distal measurements to identify causes of a behavior may produce false-negative results. Increased use of technological advances will make assessments of the more valid proximal measurements more feasible. Implications This secondary analysis tested distal and proximal predictors of making a quit attempt among the same participants and found that distal tests did not, but proximal tests did predict quit attempts. Relying on distal measurements may result in false negatives.

scholarly journals 0619 To Rely or No to Rely: Understanding the Demographics and Polysomnographic Features of False Negative Home Sleep Apnea Testing

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A237-A237
Author(s):  
P Bollu ◽  
P Gurung ◽  
T Mehta ◽  
A Monegro ◽  
S Manjamalai ◽  
...  
Keyword(s):  
Sleep Apnea ◽  
False Negative ◽  
False Negative Rate ◽  
Negative Results ◽  
False Negative Results ◽  
High Risk Populations ◽  
Home Sleep Apnea Testing ◽  
Portable Monitors ◽  
Type 3 ◽  
Apnea Testing

Abstract Introduction The current gold standard for a definitive diagnosis of OSA is an in-center Polysomnography (PSG). Home Sleep Apnea Testing(HSAT) has become an important tool in identifying high-risk populations. One of the limitations of the study is the lack of Electroencephalographic (EEG) data. This prevents the inclusion of Respiratory Effort Related Arousals (RERAs). We attempted to identify the patients whose HSAT showed an REI of less than 5 but are at risk for having sleep apnea based on the presence of airflow and thoraco-abdominal fluctuations. Methods Patients in this study were those that underwent HSAT from September 2016 till June of 2019. The studies reviewed and interpreted by board certified Sleep Specialists. Studies were done using nox-T3 sleep monitor and Nomad portable Home Sleep Testing type III devices-Both are type 3 Portable Monitors. Only those patients whose REI in their HSAT less than 5 were included in this study. All these patients had multiple airflow fluctuations in their HSAT that raised the suspicion for the presence of RERAs. None of these patients had significant hypoxemia in the HSAT.Airflow fluctuations were defined by the presence of fluctuations in the signal in the airflow channel along with increasing thoracoabdominal channels. Those patients with REI of less than 5 and without airflow fluctuations were excluded from the study. Results A total of 178 patients were recommended to undergo an in-center polysomnogram. Of those, 92 patients completed their polysomnogram with 59 patients ending up with a diagnosis of sleep apnea while 33 did not suggesting a false negative rate of 64.13%. Of those who were positive, 39 were females while 20 were males. Both groups did not differ significantly. Females had a median BMI of 32.9(28.19 for males), a median ESS of 11(8 in males) and a median RDI of 14.8(13.25). Conclusion Our study shows that both Home Sleep apnea testing can have a high proportion of false-negative results in patients exhibiting thoraco-abdominal and airflow fluctuations. The interpreting physicians should understand the limitations of the HSAT and should have a low threshold to recommend an in-center polysomnogram. Support None.

Can We State Stable Bladder? How Many Repetitions Should We Do for an Appropriate Demonstration of Involuntary Detrusor Contraction?

2015 ◽  
Vol 95 (1) ◽  
pp. 86-91 ◽  
Author(s):  
Paulo Rodrigues ◽  
Flávio Hering ◽  
Eli Cieli ◽  
Marcio DʼImperio ◽  
João Carlos Campagnari
Keyword(s):  
Wave Amplitude ◽  
False Negative ◽  
False Negative Rate ◽  
Consistent Pattern ◽  
Detrusor Contraction ◽  
Negative Results ◽  
Negative Rate ◽  
False Negative Results ◽  
Water Test ◽  
Ice Water

Aims: Involuntary Detrusor Contraction (IDC) may alter therapeutic plans; therefore, urodynamic demonstration (UD) is pivotal. We explore if same session repetitions enhance its demonstration and minimize false-negative results. Methods: Two hundred fifty two women (mean age 47 ± 5.7) had 4 full repetitions of UD with the last round filled with 4°C fluid (Ice-water test). IDC was diagnosed if with at least 3 cm H2O after artifacts were ruled out. Results: 44.4% of the cases showed IDC in the first round of the exam but it could be demonstrated in 88.5% of the women if 4 rounds are taken into account. Only 2 cases showed IDC exclusively in the first round. Nine cases (3.5%) showed IDC in the first round and only on Ice-test, while all other IDC-detected cases revealed it in scattered patterns along the repetitions. Likewise, IDC detection on the second, third and fourth rounds varied widely and unpredictably, many failing to show a consistent pattern of presentation after its detection. IDC wave amplitude did not show any correlation to the detection. Conclusions: Urodynamic repetition is a necessary procedure where IDC is important to demonstrate, as its false-negative rate is high and its unpredictable pattern of detection may be improved by repetition.

scholarly journals Real world assessment of SARS-CoV-2 nasopharyngeal swab testing in a high burden COVID-19 region

2021 ◽  
pp. 1-10
Author(s):  
Rohit B. Sangal ◽  
David R. Peaper ◽  
Craig Rothenberg ◽  
Hasan Fadlallah ◽  
Motunrayo Mobolaji-Lawal ◽  
...  
Keyword(s):  
Real World ◽  
False Negative ◽  
False Negative Rate ◽  
Healthcare Systems ◽  
Nasopharyngeal Swab ◽  
High Burden ◽  
Negative Results ◽  
Negative Rate ◽  
False Negative Results ◽  
True False

Abstract Concerns persist regarding possible false negative results that may compromise COVID-19 containment. While obtaining a true false negative rate is infeasible, using real world observation these data suggest a possible false negative rate to be approximately 2.3%. Use of a sensitive, amplified RNA platform should reassure healthcare systems.

Critical Evaluation of Impedance Phlebography for the Diagnosis of Deep Vein Thrombosis

1974 ◽  
Vol 31 (02) ◽  
pp. 273-278
Author(s):  
Kenneth K Wu ◽  
John C Hoak ◽  
Robert W Barnes ◽  
Stuart L Frankel
Keyword(s):  
Deep Vein Thrombosis ◽  
False Positive ◽  
False Negative ◽  
Critical Evaluation ◽  
Original Method ◽  
Vein Thrombosis ◽  
Negative Results ◽  
False Negative Results ◽  
Deep Vein ◽  
Positive Results

SummaryIn order to evaluate its daily variability and reliability, impedance phlebography was performed daily or on alternate days on 61 patients with deep vein thrombosis, of whom 47 also had 125I-fibrinogen uptake tests and 22 had radiographic venography. The results showed that impedance phlebography was highly variable and poorly reliable. False positive results were noted in 8 limbs (18%) and false negative results in 3 limbs (7%). Despite its being simple, rapid and noninvasive, its clinical usefulness is doubtful when performed according to the original method.

Scoring System for the Diagnosis of COVID-19

2020 ◽  
Vol 13 (1) ◽  
pp. 413-414 ◽  
Author(s):  
Mohamed Farouk Allam
Keyword(s):  
Scoring System ◽  
Clinical Symptoms ◽  
False Negative ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Negative Results ◽  
False Negative Results ◽  
Symptoms And Signs

Due to the international spread of COVID-19, the difficulty of collecting nasopharyngeal swab specimen from all suspected patients, the costs of RT-PCR and CT, and the false negative results of RT-PCR assay in 41% of COVID-19 patients, a scoring system is needed to classify the suspected patients in order to determine the need for follow-up, home isolation, quarantine or the conduction of further investigations. A scoring system is proposed as a diagnostic tool for suspected patients. It includes Epidemiological Evidence of Exposure, Clinical Symptoms and Signs, and Investigations (if available). This scoring system is simple, could be calculated in a few minutes, and incorporates the main possible data/findings of any patient.

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