Validation of a rapid antigen test as a screening tool for SARS-CoV-2 infection in asymptomatic populations. Sensitivity, specificity and predictive values

BackgroundConsultations in primary care for allergies are common. It can be difficult to differentiate between IgE-mediated (atopic) symptoms — which respond to allergen-specific interventions — and those that are non-atopic, without performing objective tests that are largely unavailable in UK general practice.Aim To develop and test a screening tool that can accurately discriminate between atopic and non-atopic individuals.Design and setting A validation study that took place in 2012 in adult volunteers aged >16 years in Scotland.MethodA questionnaire screening tool was developed using questions from a large cohort study and through consultation with experts. Participants answered the questions and had skin prick tests for four aeroallergens (house dust mite, cat, dog, and mixed grasses). Participants were classified as atopic if any average wheal diameter was ≥3 mm bigger than the negative control. Sensitivity, specificity, and positive and negative predictive values of individual and combinations of questions were calculated.ResultsIn all, 143 participants completed the questionnaire and underwent skin prick testing. Of these, 81 (56.6%) were atopic. Negative predictive values for the individual questions ranged from 48.2% (55 not atopic out of 114 negative answers) to 72.0% (18/25). An optimum combination of four questions was identified, in which a negative answer to all four questions was reported by 24 participants, 21 (87.5%) of whom were not atopic.ConclusionThe authors have identified a set of questions that correctly predict negative skin prick tests to common aeroallergens 88% of the time. These may be useful to exclude patients who do not warrant further investigation and who can reliably be advised that allergen avoidance is neither necessary nor helpful.

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Validation of an extended French version of ID Migraine™ as a migraine-screening tool

Cephalalgia ◽

10.1177/0333102414544910 ◽

2014 ◽

Vol 35 (5) ◽

pp. 437-442 ◽

Cited By ~ 9

Author(s):

Sylvie Streel ◽

Anne-Françoise Donneau ◽

Nadia Dardenne ◽

Axelle Hoge ◽

Olivier Bruyère ◽

...

Keyword(s):

Sensitivity And Specificity ◽

Screening Tool ◽

Epidemiological Studies ◽

Predictive Values ◽

French Version ◽

Gender Education ◽

French Speaking ◽

Id Migraine ◽

Sensitivity Specificity

Introduction Migraine has a considerable social, economic, physical and emotional burden but remains underdiagnosed and undertreated. A specific migraine screening tool could help remove barriers to health care and be an attractive instrument for epidemiological studies. The objective of this work was to assess the validity of an extended French version of ID Migraine™ as a migraine-screening tool. Methods Sixty-seven subjects from the NESCaV study (2010–2012) completed the migraine screen and were diagnosed by a neurologist specializing in headache medicine using the International Classification of Headache Disorders, 2nd edition criteria (gold standard). Agreement between the two diagnoses was evaluated by Cohen kappa coefficient (κ). Sensitivity, specificity and predictive values of the migraine screen were calculated. Results Migraine was diagnosed in 21 (31.3%) of the 67 subjects according to the screening tool and in 24 (35.8%) by the neurologist (κ = 0.90). The prevalence of migraine was unrelated to age, gender, education and perception of financial resources. Sensitivity and specificity of the screen were 87.5% and 100%, respectively. The screen prevalence of migraine with aura was 10.4% (sensitivity and specificity: 83.3% and 96.7%, respectively). Conclusion The extended French version of ID Migraine™ (ef-ID Migraine) is a validated tool to screen migraine in French-speaking countries.

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Beck Depression Inventory as a screening tool for depression in chronic haemodialysis patients

Australasian Psychiatry ◽

10.1177/1039856218758582 ◽

2018 ◽

Vol 26 (3) ◽

pp. 281-284 ◽

Cited By ~ 6

Author(s):

Alison Bautovich ◽

Ivor Katz ◽

Colleen Ken Loo ◽

Samuel B Harvey

Keyword(s):

Chronic Kidney Disease ◽

Major Depression ◽

Beck Depression Inventory ◽

Screening Tool ◽

Diagnostic Interview ◽

Screening Tools ◽

Chronic Haemodialysis ◽

Predictive Values ◽

Dsm Iv ◽

Sensitivity Specificity

Objectives: To evaluate the psychometric properties of the Beck Depression Inventory (BDI) and Cognitive Depression Index (CDI) as a potential screening tool for major depression in haemodialysis (HD) patients. Methods: Forty-five HD patients completed both the BDI/CDI and diagnostic interview. The interview was conducted by two experienced clinicians and was based on DSM-IV criteria. The sensitivity, specificity and positive (PPV) and negative (NPV) predictive values were then calculated. Results: A diagnosis of depression was found in 6 of the 45 participants (13.3%). Optimal cut-offs were ≥18 for the BDI (sensitivity 1.0, specificity 0.90, PPV 0.60, NPV 1.0) and ≥11 for the CDI (sensitivity 1.0, specificity 0.92, PPV 0.67, NPV 1.0). Conclusions: Both the BDI and CDI were shown to be acceptable screening tools for depression in this population of chronic HD patients. The recommended cut-off scores for both scales are higher than those suggested for the general population and slightly higher than previously found in the chronic kidney disease literature, suggesting that altered thresholds are required when using these screening tools amongst HD patients.

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Evaluation of the Access Bio CareStartTM rapid SARS-CoV-2 antigen test in asymptomatic individuals tested at a community mass-testing program in Western Massachusetts

10.1101/2021.06.17.21259109 ◽

2021 ◽

Author(s):

Sara Suliman ◽

Wilfredo R. Matias ◽

Isabel R Fulcher ◽

Francisco J. Molano ◽

Shannon Collins ◽

...

Keyword(s):

Point Of Care ◽

Quantitative Polymerase Chain Reaction ◽

High Specificity ◽

Antigen Test ◽

Predictive Values ◽

Prevalence Estimates ◽

Moderate Sensitivity ◽

Testing Site ◽

Asymptomatic Individuals ◽

Sensitivity Specificity

Background: Point-of-care antigen-detecting rapid diagnostic tests (RDTs) for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) represent a scalable tool for SARS-CoV-2 infections surveillance. Data on their performance in real-world community settings is paramount for their implementation. Method: We evaluated the accuracy of CareStartTM COVID-19 Antigen test (CareStart) in a testing site in Holyoke, Massachusetts. We compared CareStart to a SARS-CoV-2 reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) reference, using anterior nasal swab samples. We calculated the sensitivity, specificity, and expected positive and negative predictive values at different SARS-CoV-2 prevalence estimates. Results: We performed 666 tests on 591 unique individuals. 573 (86%) were asymptomatic. There were 52 positive tests by RT-qPCR. The sensitivity of CareStart was 49.0% (95% Confidence Interval (CI): 34.8 - 63.4) and specificity was 99.5% (95% CI: 98.5 - 99.9). Among positive RT-qPCR tests, the median cycle threshold (Ct) was significantly lower in samples that tested positive on CareStart. Using a Ct ≤ 30 as a benchmark for positivity increased the sensitivity to 64.9% (95% CI: 47.5 - 79.8). Conclusions: CareStart has a high specificity and moderate sensitivity. The utility of RDTs, such as CareStart, in mass implementation should prioritize use cases in which a higher specificity is more important.

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Comparison of Saliva with Healthcare Workers- and Patient-Collected Swabs in the Diagnosis of COVID-19 in a Large Cohort

10.21203/rs.3.rs-132301/v1 ◽

2020 ◽

Author(s):

Mitnala Sasikala ◽

Yelamanchili Sadhana ◽

Ketavarapu Vijayasarathy ◽

Anand Gupta ◽

Sarala kumari Daram ◽

...

Keyword(s):

Healthcare Workers ◽

Screening Tool ◽

Cost Effective ◽

Hospitalized Patients ◽

Detection Sensitivity ◽

Nasopharyngeal Swab ◽

Predictive Values ◽

Qrt Pcr ◽

Lower Detection ◽

Sensitivity Specificity

Abstract Background: A considerable amount of evidence demonstrates the potential of saliva in the diagnosis of COVID-19. Our aim was to determine the sensitivity of saliva versus swabs collected by healthcare workers (HCWs) and patients themselves to assess whether saliva detection can be offered as a cost-effective, risk-free method of SARS-CoV-2 detection.Methods: This study was conducted in a hospital involving outpatients and hospitalized patients. A total of 3018 outpatients (asymptomatic: 2683, symptomatic: 335) were screened. Of these, 200 qRT-PCR-confirmed SARS-CoV-2-positive patients were recruited (81 asymptomatic, 119 symptomatic). In addition, 101 SARS-CoV-2-positive hospitalized patients with symptoms were also enrolled in the study. From outpatients, HCWs collected nasopharyngeal swabs (NPS), saliva were obtained. From inpatients, HCWs collected swabs, patient-collected swabs, and saliva were obtained. qRT-PCR was performed to detect SARS-CoV-2 by TAQPATH assay to determine the sensitivity of saliva detection. Sensitivity, specificity and positive/negative predictive values (PPV, NPV) of detecting SARS-CoV-2 were calculated using MedCalc.Results: Of 3018 outpatient swabs tested by qRT-PCR, 200 were positive (males: 140, females: 60; aged 37.85±12.76 years). Of these, saliva was positive in 128 (64%); 39 of 81 asymptomatic (47%),89 of 119 symptomatic patients (74.78%). Sensitivity of detection was 60.9% (55.4-66.3%, CI 95%), with a negative predictive value of 36%(32.9-39.2%, CI 95%).Among 101 hospitalized patients (males:65, females: 36; aged 53.43±15.58 years), with HCW collected NPS as comparator, sensitivity of saliva was 56.1% (47.5-64.5, CI 95%), specificity 63.5%(50.4-75.3, CI95%) with PPV of 77.2% and NPV of 39.6% and that of self-swab was 52.3%(44-60.5%, CI95%), specificity 56.6% (42.3-70.2%, CI95%) with PPV 77.2% and NPV29.7%. Comparison of positivity with the onset of symptoms revealed highest detection in saliva on day 3 after onset of symptoms. Additionally, only saliva was positive in 13 (12.8%) hospitalized patients.Conclusion: Our results demonstrate the use of saliva to detect SARS-COV-2 in symptomatic patients early after the onset of symptoms. Additionally, these results suggest that saliva may not be recommended as a screening tool at the community level due to the lower detection rate than that for swabs. Saliva testing in symptomatic patients whose nasopharyngeal swab does not detect SARS-CoV-2 reduces false negativity.

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Detection of SARS-CoV-2 infection by rapid antigen test in comparison with RT-PCR in a public setting

10.1101/2021.01.22.21250042 ◽

2021 ◽

Cited By ~ 1

Author(s):

Kathrine Kronberg Jakobsen ◽

Jakob Schmidt Jensen ◽

Tobias Todsen ◽

Freddy Lippert ◽

Cyril Jean-Marie Martel ◽

...

Keyword(s):

False Negative ◽

Pcr Analysis ◽

Nasopharyngeal Swab ◽

Test Results ◽

Antigen Test ◽

Rt Pcr ◽

Predictive Values ◽

Public Setting ◽

Antigen Tests ◽

Sensitivity Specificity

AbstractBackgroundRapid and accurate detection of SARS-CoV-2 infection is essential in limiting the spread of infection during the ongoing COVID-19 pandemic. The aim of this study was to determine the accuracy of the STANDARD Q COVID-19 Ag test (SD BIOSENSOR) by comparison with RT-PCR in a public setting.MethodIndividuals aged 18 years or older who had booked an appointment for a RT-PCR test on December 26-31, 2020 at a public test center in Copenhagen, Denmark, were invited to participate. An oropharyngeal swab was collected for RT-PCR analysis, immediately followed by a nasopharyngeal swab examined by the STANDARD Q COVID-19 Ag test (SD BIOSENSOR). Sensitivity, specificity, positive and negative predictive values of the antigen test were calculated with test results from RT-PCR as reference.ResultsOverall, 4697 individuals were included (female n=2456, 53.3%; mean age: 44.7 years, SD: 16.9 years); 196 individuals were tested twice or more. Among 4811 paired conclusive test results from the RT-PCR and antigen tests, 221 (4.6%) RT-PCR tests were positive. The overall sensitivity and specificity of the antigen test were 69.7% and 99.5%, the positive and negative predictive values were 87.0% and 98.5%. Ct values were significantly higher among individuals with false negative antigen tests compared to true positives.ConclusionThe sensitivity, specificity, and predictive values found indicate that the STANDARD Q COVID-19 Ag is a good supplement to RT-PCR testing.

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Clinical validation of point-of-care SARS-COV-2 BD Veritor antigen test by a single throat swab for rapid COVID-19 status on hospital patients predominantly without overt COVID symptoms

10.1101/2021.04.12.21255299 ◽

2021 ◽

Author(s):

Jesper Bonde ◽

Ditte Ejegod ◽

Helle Pedersen ◽

Birgitte Smith ◽

Dina Cortes ◽

...

Keyword(s):

False Positive Rate ◽

False Negative ◽

Hospital Setting ◽

Nucleic Acid Amplification ◽

Adolescent Medicine ◽

Test Results ◽

Antigen Test ◽

Diagnostic Modality ◽

Predictive Values ◽

Sensitivity Specificity

AbstractBACKGROUNDFast identification of severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) infected individuals is a strategically vital task to ensure correct management and quarantine. Rapid antigen test could be a supplement to the standard-of-care Nucleic Acid Amplification Test (NAAT). The aim of this study was to determine the accuracy of the BD Veritor SARS-CoV-2 antigen test as a screening instrument in a hospital setting.METHODSA cohort of prospective samples were collected from hospital staff and patients at the Emergency, Infectious Diseases and Pediatrics and Adolescent Medicine departments at Hvidovre Hospital. All samples were collected using oropharyngeal swabs, and BD Veritor Antigen test results were paired with routine NAAT test results. Sensitivity, specificity, positive and negative predictive values of the antigen test were calculated using NAAT as reference.RESULTSOverall, 809 samples from 674 individuals were included (average age 45 years, range 0-98 years). Among all samples, 8% were SARS-CoV-2 positive by NAAT testing and 5.3% by BD Veritor. The sensitivity of the antigen test was 63.1% and specificity 99.7%. The positive predictive value was 95.3%. False-positive rate was 4%. The cycle threshold value was significantly higher among individuals with false negative antigen tests compared to true positives.CONCLUSIONThe sensitivity, specificity and positive predictive values show that the BD Veritor antigen test from oropharyngeal collected specimens performs well. Antigen testing may be a supplement, but not substitute, to NAAT testing as the primary diagnostic modality in hospital settings where fast turnaround test results may assist in decisions regarding isolation and quarantine.

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The development of a population-level clinical screening tool for self-harm repetition and suicide: the ReACT Self-Harm Rule

Psychological Medicine ◽

10.1017/s0033291712000347 ◽

2012 ◽

Vol 42 (11) ◽

pp. 2383-2394 ◽

Cited By ~ 46

Author(s):

S. Steeg ◽

N. Kapur ◽

R. Webb ◽

E. Applegate ◽

S. L. K. Stewart ◽

...

Keyword(s):

Predictive Value ◽

Screening Tool ◽

Recursive Partitioning ◽

Population Level ◽

Psychosocial Assessment ◽

Clinical Tool ◽

Predictive Values ◽

Self Harm ◽

Sensitivity Specificity ◽

A Current

BackgroundSelf-harm is a common reason for Emergency Department (ED) attendance. We aimed to develop a clinical tool to help identify patients at higher risk of repeat self-harm, or suicide, within 6 months of an ED self-harm presentation.MethodThe tool, the ReACT Self-Harm Rule, was derived using multicentre data from a prospective cohort study. Binary recursive partitioning was applied to data from two centres, and data from a separate centre were used to test the tool. There were 29 571 self-harm presentations to five hospital EDs between January 2003 and June 2007, involving 18 680 adults aged ⩾16 years. We estimated sensitivity, specificity and positive and negative predictive values to measure the performance of the tool.ResultsA self-harm presentation was classified as higher risk if at least one of the following factors was present: recent self-harm (in the past year), living alone or homelessness, cutting as a method of harm and treatment for a current psychiatric disorder. The rule performed with 95% sensitivity [95% confidence interval (CI) 94–95] and 21% specificity (95% CI 21–22), and had a positive predictive value of 30% (95% CI 30–31) and a negative predictive value of 91% (95% CI 90–92) in the derivation centres; it identified 83/92 of all subsequent suicides.ConclusionsThe ReACT Self-Harm Rule might be used as a screening tool to inform the process of assessing self-harm presentations to ED. The four risk factors could also be used as an adjunct to in-depth psychosocial assessment to help guide risk formulation. The use of multicentre data helped to maximize the generalizability of the tool, but we need to further verify its external validity in other localities.

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Discriminating Malignancy in Thyroid Nodules: The Nomogram Versus the Kwak and ACR TI-RADS

Otolaryngology ◽

10.1177/0194599820939071 ◽

2020 ◽

Vol 163 (6) ◽

pp. 1156-1165

Author(s):

Juan Xiao ◽

Qiang Xiao ◽

Wei Cong ◽

Ting Li ◽

Shouluan Ding ◽

...

Keyword(s):

Thyroid Nodules ◽

Characteristic Curve ◽

Area Under The Curve ◽

Diagnostic Study ◽

Diagnostic Efficiency ◽

Training Set ◽

Multivariable Logistic Regression Model ◽

Predictive Values ◽

Validation Set ◽

Sensitivity Specificity

Objective To develop an easy-to-use nomogram for discrimination of malignant thyroid nodules and to compare diagnostic efficiency with the Kwak and American College of Radiology (ACR) Thyroid Imaging, Reporting and Data System (TI-RADS). Study Design Retrospective diagnostic study. Setting The Second Hospital of Shandong University. Subjects and Methods From March 2017 to April 2019, 792 patients with 1940 thyroid nodules were included into the training set; from May 2019 to December 2019, 174 patients with 389 nodules were included into the validation set. Multivariable logistic regression model was used to develop a nomogram for discriminating malignant nodules. To compare the diagnostic performance of the nomogram with the Kwak and ACR TI-RADS, the area under the receiver operating characteristic curve, sensitivity, specificity, and positive and negative predictive values were calculated. Results The nomogram consisted of 7 factors: composition, orientation, echogenicity, border, margin, extrathyroidal extension, and calcification. In the training set, for all nodules, the area under the curve (AUC) for the nomogram was 0.844, which was higher than the Kwak TI-RADS (0.826, P = .008) and the ACR TI-RADS (0.810, P < .001). For the 822 nodules >1 cm, the AUC of the nomogram was 0.891, which was higher than the Kwak TI-RADS (0.852, P < .001) and the ACR TI-RADS (0.853, P < .001). In the validation set, the AUC of the nomogram was also higher than the Kwak and ACR TI-RADS ( P < .05), each in the whole series and separately for nodules >1 or ≤1 cm. Conclusions When compared with the Kwak and ACR TI-RADS, the nomogram had a better performance in discriminating malignant thyroid nodules.

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