Negative Predictive Value of Toxin Enzyme Immunoassays for Clostridium difficile in a Hospital Setting

2009 ◽  
Vol 37 (5) ◽  
pp. E82-E83
Keyword(s):  
Clostridium Difficile ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Hospital Setting ◽  
Enzyme Immunoassays

scholarly journals Prediction of Clostridium difficile infection in patients with polymerase chain reaction using a classification and regression tree

2020 ◽  
Author(s):  
Diana Martínez-Ruíz ◽  
Luis Gabriel Parra-Lara ◽  
Fernando Rosso
Keyword(s):  
Polymerase Chain Reaction ◽  
Clostridium Difficile ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Regression Tree ◽  
Antifungal Drugs ◽  
Classification And Regression Tree ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Classification And Regression

Abstract BackgroundClostridium difficile infection (CDI) is commonly diagnosed with the polymerase chain reaction (PCR), but this test finds a high percentage of false positives, so their use and interpretation in CDI is a challenge in the clinical practice. That is why it is necessary to define an algorithm to optimize the use of PCR that considers clinical characteristics to classify patients with diarrhea as CDI or without CDI. ObjectiveTo identify a predictive algorithm with the clinical features that best classify patients with CDI vs. without CDI, to help physicians in making decisions to request PCR. Materials and methodsA case-control study was conducted at Fundación Valle del Lili. The population was inpatients between 2012 and 2016, with 18 or more years, and diarrhea, abdominal pain, or other nonspecific gastrointestinal symptoms who underwent PCR. Cases were defined as patients with positive PCR for C. difficile and as controls patients with negative PCR for C. difficile. Predictive algorithms to classify patients was constructed using a classification tree, classification and regression tree (CART). ResultsA total of 149 patients were included (48 cases with positive PCR and 99 controls with negative PCR). The CART has a high capacity to classify patients with a negative PCR correctly. It includes variables about the history of antibiotics use, the use of proton-pump inhibitor, the use of ranitidine, and the use of antifungal drugs. The CART showed sensitivity 64.6%, specificity 85.8%, positive predictive value 68.8%, negative predictive value 83.3%. and AUC 79.7%.DiscussionCART had good specificity and a high negative predictive value; it could be considered as an algorithm to identify conditions that indicate when it is not necessary to perform a PCR test in a patient symptom of CDI.

scholarly journals Comparison of Salivary and Serum Enzyme Immunoassays for the Diagnosis ofHelicobacter pyloriInfection

1998 ◽  
Vol 9 (5) ◽  
pp. 277-280
Author(s):  
John M Embil ◽  
Shurjeel H Choudhri ◽  
Gerry Smart ◽  
Thomas Aldor ◽  
Norman M Pettigrew ◽  
...  
Keyword(s):  
Peptic Ulcer ◽  
Peptic Ulcer Disease ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Antibody Detection ◽  
Upper Gastrointestinal Endoscopy ◽  
Noninvasive Test ◽  
Ulcer Disease ◽  
Enzyme Immunoassays ◽  
H Pylori

Infection withHelicobacter pylorihas been established as an important risk factor for the development of peptic ulcer disease, gastritis and gastric cancer. The diagnosis ofH pyloriinfection can be established by invasive or noninvasive techniques. Two noninvasive enzyme immunoassays (EIAs) for antibody detection – HeliSal and Pylori Stat – were compared with histology. Both assays detect immunoglobulin (Ig) G directed against purifiedH pyloriantigen. The test populations consisted of 104 consecutive patients scheduled for upper gastrointestinal endoscopy. Of these patients, 97 (93%) had symptoms compatible with peptic ulcer disease. Saliva and serum were collected simultaneously at the time of endoscopy. Salivary EIA had a sensitivity of 66%, specificity of 67%, positive predictive value of 67% and negative predictive value of 66% compared with the serum EIA, where the results were 98%, 48%, 64% and 96%, respectively. Although the salivary EIA is an appealing noninvasive test, it was not a sensitive and specific assay. The serum EIA also lacked specificity, but was highly sensitive with a good negative predictive value. Although a negative serum EIA rules outH pyloriinfection, a positive result must be interpreted in the clinical context and confirmed with a more specific measure.

scholarly journals Evaluation of the QiagenartusC. difficile QS-RGQ Kit for Detection of Clostridium difficile Toxins A and B in Clinical Stool Specimens

2015 ◽  
Vol 53 (6) ◽  
pp. 1942-1944 ◽  
Author(s):  
Nathalie Jazmati ◽  
Pia Wiegel ◽  
Božica Ličanin ◽  
Georg Plum
Keyword(s):  
Nucleic Acid ◽  
Clostridium Difficile ◽  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Nucleic Acid Amplification Test ◽  
Nucleic Acid Amplification ◽  
Content Type ◽  
Stool Specimens ◽  
Sensitivity Specificity

We compared the QiagenartusC. difficile QS-RGQ kit, a new nucleic acid amplification test for the detection ofClostridium difficiletoxins in stool specimens, with the Cepheid XpertC. difficiletest. The sensitivity, specificity, positive predictive value, and negative predictive value for the QiagenartusC. difficile QS-RGQ test were 100%, 89.5%, 60.9%, and 100%, and those for the Cepheid XpertC. difficiletest were 100%, 90%, 62.2%, and 100%, respectively.

scholarly journals An algorithm to safely manage oral food challenge in an office-based setting for children with multiple food allergies

2021 ◽  
Vol 5 (1) ◽  
pp. 030-037
Author(s):  
Cottel Nathalie ◽  
Dieme Aïcha ◽  
Orcel Véronique ◽  
Chantran Yannick ◽  
Bourgoin-Heck Mélisande ◽  
...  
Keyword(s):  
Negative Predictive Value ◽  
Predictive Value ◽  
Validation Cohort ◽  
Hospital Setting ◽  
Food Challenge ◽  
Oral Food Challenge ◽  
Low Risk ◽  
Food Allergies ◽  
Machine Learning Approach ◽  
High Positive Predictive Value

Background: In France, from 30% to 35% of children suffer from multiple food allergies (MFA). The gold standard to diagnosis a food allergy is the oral food challenge (OFC) which is conducted in a hospital setting due to risk of anaphylaxis. The aim of this study was to evaluate an algorithm to predict OFCs at low risk of anaphylaxis that could safely be performed in an office-based setting. Methods: Children with MFA and at least one open OFC reactive or non-reactive to other allergens were included. The algorithm was based on multiple clinical and biological parameters related to food allergens, and designed mainly to predict “low-risk” OFCs i.e., practicable in an office-based setting. The algorithm was secondarily tested in a validation cohort. Results: Ninety-one children (median age 9 years) were included; 94% had at least one allergic comorbidity with an average of three OFCs per child. Of the 261 OFCs analyzed, most (192/261, 74%) were non-reactive. The algorithm failed to correctly predict 32 OFCs with a potentially detrimental consequence but among these only three children had severe symptoms. One hundred eighty-four of the 212 “low-risk” OFCs, (88%) were correctly predicted with a high positive predictive value (87%) and low negative predictive value (44%). These results were confirmed with a validation cohort giving a specificity of 98% and negative predictive value of 100%. Conclusion: This study suggests that the algorithm we present here can predict “low-risk” OFCs in children with MFA which could be safely conducted in an office-based setting. Our results must be confirmed with an algorithm-based machine-learning approach.

scholarly journals Comparison of GenomEra C. difficile and Xpert C. difficile as Confirmatory Tests in a Multistep Algorithm for Diagnosis of Clostridium difficile Infection

2014 ◽  
Vol 53 (1) ◽  
pp. 332-335 ◽  
Author(s):  
Luis Alcalá ◽  
Elena Reigadas ◽  
Mercedes Marín ◽  
Antonia Fernández-Chico ◽  
Pilar Catalán ◽  
...  
Keyword(s):  
Clostridium Difficile ◽  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Clostridium Difficile Infection ◽  
Predictive Value ◽  
Confirmatory Test ◽  
Content Type ◽  
Diagnostic Algorithms ◽  
Confirmatory Tests ◽  
Sensitivity Specificity

We compared two multistep diagnostic algorithms based on C. Diff Quik Chek Complete and, as confirmatory tests, GenomEraC. difficileand XpertC. difficile. The sensitivity, specificity, positive predictive value, and negative predictive value were 87.2%, 99.7%, 97.1%, and 98.3%, respectively, for the GenomEra-based algorithm and 89.7%, 99.4%, 95.5%, and 98.6%, respectively, for the Xpert-based algorithm. GenomEra represents an alternative to Xpert as a confirmatory test of a multistep algorithm forClostridium difficileinfection (CDI) diagnosis.

scholarly journals DIAGNOSTIC USEFULNESS OF CBNAAT IN DIAGNOSING PEDIATRIC TUBERCULOSIS: A COMPARATIVE STUDY.

2020 ◽  
Vol 4 (5) ◽  
Author(s):  
Vivek Kumar ◽  
Manoj Kumar ◽  
Gopal Shankar Sahni
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Gastric Lavage ◽  
Hospital Setting ◽  
Rapid Test ◽  
Diagnostic Usefulness ◽  
Pediatric Tuberculosis ◽  
Sensitivity Specificity

Introduction: Tuberculosis (TB) caused by the bacterium Mycobacterium tuberculosis, remains one of the major health problems in India. The recent introduction of Cartridge-Based Nucleic Acid Amplification Test (CBNAAT) also known as Gene Xpert MTB/ RIF assay has significantly transformed the diagnostics of TB. The present study aimed diagnostic usefulness of CBNAAT for diagnosing pediatric tuberculosis in our hospital setting. Material and Methods: This study was carried out at department of Pediatric, Skmch Bihar India from oct 2018 to Nov 2019. Total 447 patients showing symptoms and signs of suspected localized and/or disseminated tuberculosis or having history of close contact with diagnosed tuberculosis patients admitted in our hospital during the study period were included in this study. Samples (pulmonary and extrapulmonary) were collected from the subjects and put to test for CBNAAT, Zeihl-Neelsen (ZN) smear and culture. Results: Among the pulmonary samples, CBNAAT detected MTB in 23 of the 108 sputum/induced sputum samples (21.29%), 89 of the 248 gastric lavage/aspirate samples (35.88%) and 0 of the 5 bronchoalveolar lavage samples (0%). Among the extrapulmonary samples, CBNAAT detected MTB in 9 of the 63 CSF samples (14.28%), 1 of the 13 pleural fluid samples (7.69%), 0 of the 6 ascitic fluid samples (0%) and 3 of the 4 lymph node aspirate samples obtained by FNAC(75%). Sensitivity, specificity, positive predictive value and negative predictive value of CBNAAT in reference to culture are 90.15%, 98.09%, 95.2%and 95.2%respectively. Sensitivity, specificity, positive predictive value and negative predictive value of CBNAAT in reference to ZN smear are 100%, 91.47%, 76% and 100% respectively. Conclusion: CBNAAT assay is a rapid test which identifies both the presence of Mycobacterium tuberculosis (MTB) (with high sensitivity, specificity, positive predictive value and negative predictive value) and rifampicin resistance associated with mutation of rpoB gene in a single test. It also helps to avoid injudicious use of anti-tuberculosis drugs. Keywords: CBNAAT; MTB; ZN smear; Culture

Tissue plasminogen activator as a novel diagnostic aid in acute pulmonary embolism

VASA ◽  
2014 ◽  
Vol 43 (6) ◽  
pp. 450-458 ◽  
Author(s):  
Julio Flores ◽  
Ángel García-Avello ◽  
Esther Alonso ◽  
Antonio Ruíz ◽  
Olga Navarrete ◽  
...  
Keyword(s):  
Pulmonary Embolism ◽  
Negative Predictive Value ◽  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Predictive Value ◽  
Acute Pulmonary Embolism ◽  
Enzyme Linked Immunosorbent Assay ◽  
Diagnostic Utility ◽  
Tissue Plasminogen ◽  
D Dimer

Background: We evaluated the diagnostic efficacy of tissue plasminogen activator (tPA), using an enzyme-linked immunosorbent assay (ELISA) and compared it with an ELISA D-dimer (VIDAS D-dimer) in acute pulmonary embolism (PE). Patients and methods: We studied 127 consecutive outpatients with clinically suspected PE. The diagnosis of PE was based on a clinical probability pretest for PE and a strict protocol of imaging studies. A plasma sample to measure the levels of tPA and D-dimer was obtained at enrollment. Diagnostic accuracy for tPA and D-dimer was determined by the area under the receiver operating characteristic (ROC) curve. Sensitivity, specificity, predictive values, and the diagnostic utility of tPA with a cutoff of 8.5 ng/mL and D-dimer with a cutoff of 500 ng/mL, were calculated for PE diagnosis. Results: PE was confirmed in 41 patients (32 %). Areas under ROC curves were 0.86 for D-dimer and 0.71 for tPA. The sensitivity/negative predictive value for D-dimer using a cutoff of 500 ng/mL, and tPA using a cutoff of 8.5 ng/mL, were 95 % (95 % CI, 88–100 %)/95 % (95 % CI, 88–100 %) and 95 % (95 % CI, 88–100 %)/94 %), respectively. The diagnostic utility to exclude PE was 28.3 % (95 % CI, 21–37 %) for D-dimer and 24.4 % (95 % CI, 17–33 %) for tPA. Conclusions: The tPA with a cutoff of 8.5 ng/mL has a high sensitivity and negative predictive value for exclusion of PE, similar to those observed for the VIDAS D-dimer with a cutoff of 500 ng/mL, although the diagnostic utility was slightly higher for the D-dimer.

D-Dimer Test and Diagnosis of Deep Vein Thrombosis: A Comparative Study of 7 Assays

1996 ◽  
Vol 76 (04) ◽  
pp. 518-522 ◽  
Author(s):  
A Elias ◽  
I Aptel ◽  
B Huc ◽  
J J Chale ◽  
F Nguyen ◽  
...  
Keyword(s):  
Deep Vein Thrombosis ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Latex Agglutination ◽  
Lower Limbs ◽  
First Episode ◽  
Lower Sensitivity ◽  
Vein Thrombosis ◽  
Deep Vein ◽  
D Dimer

SummaryThe current D-Dimer ELISA methods provide high sensitivity and negative predictive value for the diagnosis of deep vein thrombosis but these methods are not suitable for emergency or for individual determination. We have evaluated the performance of 3 newly available fast D-Dimer assays (Vidas D-Di, BioMerieux; Instant IA D-Di, Stago; Nycocard D-Dimer, Nycomed) in comparison with 3 classic ELISA methods (Stago, Organon, Behring) and a Latex agglutination technique (Stago). One-hundred-and-seventy-one patients suspected of presenting a first episode of deep vein thrombosis were investigated. A deep vein thrombosis was detected in 75 patients (43.8%) by ultrasonic duplex scanning of the lower limbs; in 11 of them the thrombi were distal and very limited in size (<2 cm). We compared the performance of the tests by calculating their sensitivity, specificity, positive and negative predictive value for different cut-off levels and by calculating the area under ROC curves. The concordance of the different methods was evaluated by calculating the kappa coefficient. The performances of the 3 classic ELISA and of the Vidas D-Di were comparable and kappa coefficients indicated a good concordance between the results provided by these assays. Their sensitivity slightly declined for detection of the very small thrombi. Instant IA D-Di had a non-significantly lower sensitivity and negative predictive value than the 4 previous assays; however its performance was excellent for out-patients. As expected, the Latex assay had too low a sensitivity and negative predictive value to be recommended. In our hands, Nycocard D-Dimer also exhibited low sensitivity and negative predictive value, which were significantly improved when the plasma samples were tested by the manufacturer. Thus significant progress has been made, allowing clinical studies to be planned to compare the safety and cost-effectiveness of D-Dimer strategy to those of the conventional methods for the diagnosis of venous thrombosis.

Diagnosis of Deep Vein Thrombosis by Combination of Doppler Ultrasound Flow Examination and Strain Gauge Plethysmography

1982 ◽  
Vol 47 (02) ◽  
pp. 141-144 ◽  
Author(s):  
H Bounameaux ◽  
B Krähenbühl ◽  
S Vukanovic
Keyword(s):  
Deep Vein Thrombosis ◽  
Negative Predictive Value ◽  
Doppler Ultrasound ◽  
Strain Gauge ◽  
Predictive Value ◽  
Lower Limbs ◽  
Vein Thrombosis ◽  
Non Invasive ◽  
Strain Gauge Plethysmography ◽  
Deep Vein

SummaryDoppler ultrasound flow examination, strain gauge plethysmography and contrast venography were performed in 160 lower limbs of 80 in-patients. Deep vein thrombosis (DVT) was suspected in 87 limbs. Using measurement of venous stop-flow pressure, the Doppler method had an overall sensitivity of 83%. By combined use of Doppler and Plethysmography, sensitivity was increased to 96%. Specificity was 62% and 51%, respectively. With a positive and a negative predictive value of 80% and 73%, respectively, the combination of both non-invasive methods cannot reliably replace venography in the diagnosis of DTV, although all (40/40) thromboses proximal to or involving the popliteal segment were detected by either Doppler and Plethysmography or both.After exclusion of 14 patients (18%) suffering from conditions known to alter the results of these non-invasive methods, the positive predictive value of abnormal findings in both Doppler and Plethysmography was increased to 94% for suspected limbs, whilst negative predictive value of both negative Doppler and Plethysmography was 90%, allowing the avoidance of venography in these patients.

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