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.

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 Effect of omeprazole, rabeprazole, and rebamipide on the accuracy of urea breath test in patients with Helicobacter pylori infection

2010 ◽  
Vol 4 (2) ◽  
pp. 337-342
Author(s):  
Duangporn Thong-Ngam ◽  
Maneerat Chayanupatkul ◽  
Thirada Thongbai
Keyword(s):  
Proton Pump Inhibitors ◽  
Proton Pump ◽  
Breath Test ◽  
False Negative ◽  
False Negative Rate ◽  
Urea Breath Test ◽  
Once Daily ◽  
Negative Results ◽  
Negative Rate ◽  
H Pylori

Abstract Background: The urea breath test (UBT) has been widely used for H. pylori eradication after treatment. The breath test could be adversely affected by various factors including proton pump inhibitors (PPIs) that are also used in the therapy for H. pylori infection. Objective: Determine the effect of omeprazole, rabeprazole and the mucoprotective agent rebamipide, on the UBT. Methods: Fifty-six patients with dyspepsia and positive for H. pylori by rapid urease test were enrolled. They were classified into three groups: Group 1 (n=25) received omeprazole 20 mg once daily, group 2 (n=13) received rabeprazole 20 mg once daily, and group 3 (n=18) received rebamipide 100 mg three times a day. All patients received a 14-day course of their medications. UBT was performed on day 0 as a baseline and on day 14 in all patients. In patient with negative results of UBT on day 14, the UBT was performed in consecutive week until the test became positive. Results: Fifty-six patients (20 men and 36 women) participated in the study. Their mean age was 46.77±14.3 years. False negative rate after 14-day treatment in omeprazole, rabeprazole and rebamipide group were 20.0%, 30.8%, and 0% respectively. There was a significant difference between 13C level in patients with negative and positive UBT results (2.7±0.7 vs.22.9±3.7/mL, p=0.025). The reversal of false negative to true positive tests occurred within two weeks after discontinuation of omeprazole and rabeprazole. Conclusion: Proton pump inhibitors had an effect on the accuracy of H. pylori detection using UBT. Rabeprazole revealed a higher false negative rate in the UBT than omeprazole. The mucoprotective drug, rebamipide, did not influence negative results in the UBT.

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.

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.

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.

Detection of Streptococcus pneumoniae in Sputum Samples by Real- Time PCR.

2020 ◽  
Vol 18 ◽  
Author(s):  
Pegah Shakib ◽  
Mohammad Reza Zolfaghari
Keyword(s):  
Streptococcus Pneumoniae ◽  
Real Time ◽  
Real Time Pcr ◽  
False Negative ◽  
Cross Sectional Study ◽  
Laboratory Culture ◽  
Cross Sectional ◽  
Negative Results ◽  
False Negative Results ◽  
Pcr Method

Background: Conventional laboratory culture-based methods for diagnosis of Streptococcus pneumoniae are time-consuming and yield false negative results. Molecular methods including real-time (RT)-PCR rapid methods and conventional PCR due to higher sensitivity and accuracy have been replaced instead traditional culture assay. The aim of the current study was to evaluate lytA gene for detection of Streptococcus pneumoniae in the cerebrospinal fluid of human patients with meningitis using real-time PCR assay. Material and Methods: In this cross-sectional study, a total of 30 clinical specimens were collected from patients in a period from September to December 2018. In order to evaluate the presence of lytA gene, conventional and real-time PCR methods were used without culture. Results: From 30 sputum samples five (16.66%) isolates were identified as S. pneumoniae by lytA PCR and sequencing. Discussion: In this research, an accurate and rapid real-time PCR method was used, which is based on lytA gene for diagnosis of bacteria so that it can be diagnosed. Based on the sequencing results, the sensitivity for detection of lytA gene was 100% (5/5).

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