scholarly journals Urgent Care Study of the LumiraDx SARS-CoV-2 Ag Test for Rapid Diagnosis of COVID-19

2021 ◽  
Author(s):  
Jared Gresh ◽  
Harold Kisner ◽  
Brian DuChateau
Keyword(s):  
False Negative ◽  
False Negative Rate ◽  
Rapid Diagnosis ◽  
Urgent Care ◽  
Reference Laboratory ◽  
Swab Sample ◽  
Community Based ◽  
Negative Results ◽  
Care Study ◽  
Regional Reference

Abstract BackgroundTesting individuals suspected of SARS-CoV-2 infection is essential to reduce the spread of disease. The purpose of this study was to determine the false negativity rate of the LumiraDx SARS-CoV-2 Ag Test when utilized for testing individuals suspected of SARS-CoV-2 infection within 12 days of symptom onset. MethodsConcurrent swab samples were collected from patients suspected of SARS-CoV-2 infection by their healthcare provider within two different urgent care centers. One swab was tested using the LumiraDx SARS-CoV-2 Ag Test. Negative results in patients considered at moderate to high risk of SARS-CoV-2 infection were confirmed at a regional reference laboratory by PCR using the additional swab sample. ResultsFrom October 19, 2020 – January 3, 2021, a total of 2241 tests were performed using the LumiraDx SARS-CoV-2 Ag Test, with 549 (24.5%) testing positive and 1692 (75.5%) testing negative. A subset (800) of the samples rendering a negative LumiraDx SARS-CoV-2 Ag Test were also tested using a PCR-based test for SARS-CoV-2. Of this subset, 770 (96.3%) tested negative, and 30 (3.8%) tested positive. A cycle threshold (CT) was available for 17 of the 30 specimens that yielded discordant results, with an average CT value of 31.2, an SD of 3.0, and a range of 25.2–36.3. CT was >30.0 in 11/17 specimens (64.7%). ConclusionsThis study demonstrates that negative results obtained with the LumiraDx SARS-CoV-2 Ag Test had 96.3% agreement with PCR-based SARS-CoV-2 tests, with a low false negative rate of 3.8% when used in a community-based setting.

scholarly journals Urgent Care Study of the LumiraDx SARS-CoV-2 Ag Test for Rapid Diagnosis of COVID-19

2021 ◽  
Author(s):  
Jared Gresh ◽  
Harold Kisner ◽  
Brian DuChateau
Keyword(s):  
False Negative ◽  
False Negative Rate ◽  
Rapid Diagnosis ◽  
Urgent Care ◽  
Reference Laboratory ◽  
Swab Sample ◽  
Community Based ◽  
Negative Results ◽  
Care Study ◽  
Regional Reference

Abstract BackgroundTesting individuals suspected of SARS-CoV-2 infection is essential to reduce the spread of disease. The purpose of this study was to determine the false negativity rate of the LumiraDx SARS-CoV-2 Ag Test when utilized for testing individuals suspected of SARS-CoV-2 infection within 12 days of symptom onset. MethodsConcurrent swab samples were collected from patients suspected of SARS-CoV-2 infection by their healthcare provider within two different urgent care centers. One swab was tested using the LumiraDx SARS-CoV-2 Ag Test. Negative results in patients considered at moderate to high risk of SARS-CoV-2 infection were confirmed at a regional reference laboratory by PCR using the additional swab sample. ResultsFrom October 19, 2020 – January 3, 2021, a total of 2241 tests were performed using the LumiraDx SARS-CoV-2 Ag Test, with 549 (24.5%) testing positive and 1692 (75.5%) testing negative. A subset (800) of the samples rendering a negative LumiraDx SARS-CoV-2 Ag Test were also tested using a PCR-based test for SARS-CoV-2. Of this subset, 770 (96.3%) tested negative, and 30 (3.8%) tested positive. A cycle threshold (CT) was available for 17 of the 30 specimens that yielded discordant results, with an average CT value of 31.2, an SD of 3.0, and a range of 25.2–36.3. CT was >30.0 in 11/17 specimens (64.7%). ConclusionsThis study demonstrates that negative results obtained with the LumiraDx SARS-CoV-2 Ag Test had 96.3% agreement with PCR-based SARS-CoV-2 tests, with a low false negative rate of 3.8% when used in a community-based setting.

scholarly journals Urgent care study of the LumiraDx SARS-CoV-2 Ag Test for rapid diagnosis of COVID-19

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Jared Gresh ◽  
Harold Kisner ◽  
Brian DuChateau
Keyword(s):  
False Negative ◽  
False Negative Rate ◽  
Urgent Care ◽  
Reference Laboratory ◽  
Chain Reaction ◽  
Community Based ◽  
Negative Results ◽  
Polymerase Chain ◽  
Care Study ◽  
Regional Reference

Abstract Background Testing individuals suspected of severe acute respiratory syndrome–like coronavirus 2 (SARS-CoV-2) infection is essential to reduce the spread of disease. The purpose of this retrospective study was to determine the false negativity rate of the LumiraDx SARS-CoV-2 Ag Test when utilized for testing individuals suspected of SARS-CoV-2 infection. Methods Concurrent swab samples were collected from patients suspected of SARS-CoV-2 infection by their healthcare provider within two different urgent care centers located in Easton, MA, USA and East Bridgewater, MA, USA. One swab was tested using the LumiraDx SARS-CoV-2 Ag Test. Negative results in patients considered at moderate to high risk of SARS-CoV-2 infection were confirmed at a regional reference laboratory by polymerase chain reaction (PCR) using the additional swab sample. The data included in this study was collected retrospectively as an analysis of routine clinical practice. Results From October 19, 2020 to January 3, 2021, a total of 2241 tests were performed using the LumiraDx SARS-CoV-2 Ag Test, with 549 (24.5%) testing positive and 1692 (75.5%) testing negative. A subset (800) of the samples rendering a negative LumiraDx SARS-CoV-2 Ag Test was also tested using a PCR-based test for SARS-CoV-2. Of this subset, 770 (96.3%) tested negative, and 30 (3.8%) tested positive. Negative results obtained with the LumiraDx SARS-CoV-2 Ag test demonstrated 96.3% agreement with PCR-based tests (CI 95%, 94.7–97.4%). A cycle threshold (CT) was available for 17 of the 30 specimens that yielded discordant results, with an average CT value of 31.2, an SD of 3.0, and a range of 25.2–36.3. CT was > 30.0 in 11/17 specimens (64.7%). Conclusions This study demonstrates that the LumiraDx SARS-CoV-2 Ag Test had a low false-negative rate of 3.8% when used in a community-based setting.

scholarly journals Pooling of Upper Respiratory Specimens Using a SARS-CoV-2 Real-time RT-PCR Assay Authorized for Emergency Use in Low-Prevalence Populations for High-Throughput Testing

2020 ◽  
Vol 7 (11) ◽  
Author(s):  
Gwynngelle A Borillo ◽  
Ron M Kagan ◽  
Russell E Baumann ◽  
Boris M Fainstein ◽  
Lamela Umaru ◽  
...  
Keyword(s):  
Real Time ◽  
False Negative ◽  
False Negative Rate ◽  
Nucleic Acid Amplification ◽  
Rt Pcr ◽  
Pooled Testing ◽  
Negative Results ◽  
Single Positive ◽  
Upper Respiratory ◽  
Respiratory Specimens

Abstract Background Nucleic acid amplification testing is a critical tool for addressing the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Specimen pooling can increase throughput and conserve testing resources but requires validation to ensure that reduced sensitivity does not increase the false-negative rate. We evaluated the performance of a real-time reverse transcription polymerase chain reaction (RT-PCR) test authorized by the US Food and Drug Administration (FDA) for emergency use for pooled testing of upper respiratory specimens. Methods Positive specimens were selected from 3 prevalence groups, 1%–3%, >3%–6%, and >6%–10%. Positive percent agreement (PPA) was assessed by pooling single-positive specimens with 3 negative specimens; performance was assessed using Passing-Bablok regression. Additionally, we assessed the distributions of RT-PCR cycle threshold (Ct) values for 3091 positive specimens. Results PPA was 100% for the 101 pooled specimens. There was a linear relationship between Ct values for pooled and single-tested specimens (r = 0.96–0.99; slope ≈ 1). The mean pooled Ct shifts at 40 cycles were 2.38 and 1.90, respectively, for the N1 and N3 targets. The median Cts for 3091 positive specimens were 25.9 (N1) and 24.7 (N3). The percentage of positive specimens with Cts between 40 and the shifted Ct was 1.42% (N1) and 0.0% (N3). Conclusions Pooled and individual testing of specimens positive for SARS-CoV-2 demonstrated 100% agreement, which demonstrates the viability of pooled specimens for SARS-COV-2 testing using a dual-target RT-PCR system. Pooled specimen testing can help increase testing capacity for SARS-CoV-2 with a low risk of false-negative results.

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 Histopathologic Review of Previously Negative Prostatic Core Needle Biopsies following a New Diagnosis of Adenocarcinoma of the Prostate by Core Needle Biopsies: Implications for Quality Assurance Programs

2008 ◽  
Vol 1 ◽  
pp. CPath.S581
Author(s):  
Jay Patel ◽  
Lester J. Layfield
Keyword(s):  
Quality Assurance ◽  
Core Biopsy ◽  
False Negative ◽  
False Negative Rate ◽  
Intraepithelial Neoplasia ◽  
Surgical Pathology ◽  
Core Needle ◽  
Prostate Needle Biopsy ◽  
Negative Results ◽  
New Diagnosis

Programs for quality assurance are increasingly important in surgical pathology. Many quality assurance (QA) techniques for surgical pathology were adopted from procedures introduced in cytopathology. Surgical pathology specimens have diminished in size such that the majority of diagnostic biopsies of prostatic lesions are now core needle biopsies. These specimens raise issues similar to those of cytology specimens, including concerns regarding adequacy and the representative nature of the biopsy. Due to sample size, some neoplasms may not be diagnosed on initial biopsy, raising concerns regarding false negative results. Cytopathologists have instituted QA procedures including review of all previously negative slides received within five years prior to the new diagnosis of high grade squamous intraepithelial lesion or gynecologic malignancy. No such requirement exists in surgical pathology for review of core biopsies. The Department of Pathology at the University of Utah instituted a QA policy requiring review of prior negative prostatic needle biopsies following a new diagnosis of prostatic adenocarcinoma. We reviewed five years of QA records of prostate needle biopsy review. During this time, nine hundred and fifty-eight core biopsy sets were performed. Two hundred and ninety-five of these contained at least one biopsy with a diagnosis of adenocarcinoma. Two hundred and eight patients had a prior set of prostatic needle biopsies with a diagnosis of adenocarcinoma. The remaining 87 had prior biopsies with either a diagnosis of prostatic intraepithelial neoplasia (23), small atypical acinar proliferation (21) or no evidence of malignancy (43). QA review of these 87 cases revealed two biopsies which revealed foci of adenocarcinoma. Both had been initially diagnosed as no evidence of malignancy. The false negative rate for core biopsy was 0.68%. In an additional twenty-one cases, microscopic foci of atypical small acinar proliferations were found in core biopsies antedating the positive core biopsy (7.1%).

scholarly journals Avoiding COVID-19 Hospital Outbreaks: RT-PCR Swab and Clinical Assessment

2021 ◽  
Author(s):  
Luca Allievi ◽  
Amedeo Bongarzoni ◽  
Guido Tassinario ◽  
Stefano Carugo
Keyword(s):  
Clinical Assessment ◽  
False Negative ◽  
False Negative Rate ◽  
High Specificity ◽  
Diagnostic Process ◽  
Rt Pcr ◽  
Negative Results ◽  
High False Negative Rate ◽  
Degree Of Confidence ◽  
Low Sensitivity

Nasopharyngeal RT-PCR swab test for COVID-19 diagnosis has a high specificity but also a low sensitivity. The high false-negative rate and the overconfidence in negative results sometimes lead to hospital outbreaks. Therefore, we recommend always integrating the clinical assessment in the diagnostic process, mostly after the test, to determine what degree of confidence can be attributed to a negative result.

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 Central retesting of breast cancer with HER2 immunohistochemistry score of 0 or 1+ using silver-enhanced in situ hybridisation: a multicentre, prospective study in Greece

2014 ◽  
Vol 5 (1) ◽  
pp. 20-28
Author(s):  
Savvas Papadopoulos ◽  
Petroula Arapantoni-Dadioti ◽  
Konstantinos Sfikas ◽  
Artemis Stylianidou ◽  
Helen Trichia ◽  
...  
Keyword(s):  
In Situ Hybridisation ◽  
False Negative ◽  
False Negative Rate ◽  
Growth Factor Receptor ◽  
Chromosome 17 ◽  
Her2 Status ◽  
Breast Cancers ◽  
Negative Results ◽  
Status Assessment

Abstract Newly diagnosed invasive breast cancers should be evaluated for Human Epidermal Growth Factor Receptor 2 (HER2) status by immunohistochemistry (IHC) and/or in situ hybridisation (ISH) to determine eligibility for trastuzumab or other HER2-targeted therapies. Previous reports of high discordance rates between IHC and ISH have raised concerns over the accuracy of HER2 testing, especially when IHC is conducted locally. This study aimed to determine the rate of false-negative IHC results at three pathology centres (one central, two local) in Greece by central retesting of 240 prospectively collected invasive breast cancers scored as IHC 0/1+ at initial testing. All samples were from female patients (median age 58.0 years). Initial IHC tests utilised either the CB11 (159/239; 66.5%) or 4B5 (80/239; 33.5%) antibodies and were scored as 0 in 105/240 cases (43.8%) and 1+ in 135/240 cases (56.3%). All samples were centrally retested by automated silver in situ hybridisation (SISH). Of 237 samples with SISH staining suitable for assessment, 223 (94.1%; 95% confidence interval 90.3–96.5%) were classed as SISH-negative (HER2:chromosome enumeration probe 17 (CEP17) <1.8). Eight tested SISH-positive (HER2:CEP17 >2.2), providing a false-negative rate of 3.4%. A further four samples (1.7%) exhibited equivocal amplification status (HER2:CEP17 1.8–2.2) and two (0.8%) showed polysomy of chromosome 17. The proportion of SISH-negative results did not significantly differ between the IHC 0 and 1+ subgroups (95.2% vs. 93.2%; p=0.505). In conclusion, the low observed rate of false-negative IHC results in this study supports the use of IHC for initial HER2 status assessment in local or central laboratories in Greece.

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