Estimation of sensitivity, specificity and predictive values of two serologic tests for the detection of antibodies against Actinobacillus pleuropneumoniae serotype 2 in the absence of a reference test (gold standard)

2001 ◽  
Vol 51 (3-4) ◽  
pp. 227-243 ◽  
Author(s):  
Claes Enøe ◽  
Søren Andersen ◽  
Vibeke Sørensen ◽  
Preben Willeberg
Keyword(s):  
Gold Standard ◽  
Actinobacillus Pleuropneumoniae ◽  
Reference Test ◽  
Predictive Values ◽  
Serologic Tests ◽  
Sensitivity Specificity

scholarly journals Investigation of the rapid immunochromatographic test performance in the diagnosis of syphilis; comparison of four serological methods

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Huseyin Agah Terzi ◽  
Ozlem Aydemir ◽  
Engin Karakece ◽  
Huseyin Hatipoglu ◽  
Mehmet Olmez ◽  
...  
Keyword(s):  
Test Performance ◽  
Gold Standard ◽  
Treponema Pallidum ◽  
Rapid Test ◽  
Immunochromatographic Test ◽  
Rapid Plasma Reagin ◽  
Serum Samples ◽  
Hemagglutination Assay ◽  
Predictive Values ◽  
Sensitivity Specificity

AbstractObjectivesTo test the performance of the newly available rapid test for syphilis, we compared it with Treponema pallidum hemagglutination assay (TPHA). Additionally, we investigated the performance of rapid plasma reagin (RPR) and chemiluminescence microparticle immunoassays (CMIA) at our laboratory using TPHA as a gold standard.MethodsThe serum samples of 595 patients with the pre-diagnosis of syphilis were studied by four serological methods. The sensitivity, specificity, and predictive values of RPR, CMIA, and syphilis rapid test were assessed by utilizing TPHA as a gold standard for the diagnosis of syphilis.ResultsOf the patients, 6.2% (37/595) had positive RPR, 5.5% (33/595) had positive CMIA, 5.5% (33/595) had a positive rapid immunochromatographic method and 5% (30/595) had positive TPHA. When TPHA results were taken as the reference, the sensitivity of the rapid test for syphilis was 100%, the specificity was 99.5%, PPV was 90.9%, and NPV was 100.0%.ConclusionsIt was observed that the rapid test for syphilis used in the study was quite successful, its cost was appropriate, and the test was very fast and easy to apply. At the same time, the agreement between syphilis rapid test and TPHA was found to be excellent.

scholarly journals The discrepancy between manual and computerized leukocyte and thrombocyte counts

2016 ◽  
Vol 43 (3) ◽  
pp. 95
Author(s):  
Bambang Permono ◽  
Retno Asih ◽  
I Dewa Gede Ugrasena
Keyword(s):  
Gold Standard ◽  
Leukocyte Count ◽  
Predictive Values ◽  
Thrombocyte Count ◽  
Randomized Sampling ◽  
Manual Group ◽  
Manual Examination ◽  
Blood Specimens ◽  
Sensitivity Specificity ◽  
Normal Leukocyte

Background Discrepancy between results of leukocyte and throm-bocyte count by computerized and manual examination may existObjective To determine the discrepancy between computerizedand manual leukocyte and thrombocyte count.Methods The design was a randomized sampling cross sectionalstudy. The blood sample was examined with computerized CellDyn 1400 instrument for the leukocyte and thrombocyte count. Formanual examination, blood smear was performed to measurethrombocyte while leukocyte was measured in Improved Neubauerhemocytometer. The results of computerized examination wereused as gold standard. Sensitivity, specificity, predictive values ofmanual count were calculated. The agreement of Kappa and McNemar test were determinedResults Blood specimens drawn from 100 patients with differentkinds of diagnoses were examined using computerized and manualmethods. In computerized group, 66% had normal leukocyte and55% had normal thrombocyte count. In the manual group, 78% ofsubjects had normal leukocyte and 82% had normal thrombocytecount. From leukocyte examination, the sensitivity of manual countwas 87.9%, specificity was 41.2%, and positive predictive valuewas 74.36 with the agreement of Kappa of 0.32 and Mc Nemarvalue of 0.036. From thrombocyte examination, the sensitivity was96.4%, specificity was 35.6%, and positive predictive value was64.6 with the agreement of Kappa of 0.41 and Mc Nemar value of0.41.Conclusion The result of manual thrombocyte count was in ac-cordance with computerized with the agreement of Kappa of 0.41.On the other hand, there was a discrepancy between manual infavor of computerized leukocyte count with the agreement of Kappaof 0.32

Good diagnostic accuracy of a chemiluminescent immunoassay in stool samples for diagnosis of Helicobacter pylori infection in patients with dyspepsia

2016 ◽  
Vol 64 (2) ◽  
pp. 388-391 ◽  
Author(s):  
María José Ramírez-Lázaro ◽  
Josep Lite ◽  
Sergio Lario ◽  
Pepa Pérez-Jové ◽  
Antònia Montserrat ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Gold Standard ◽  
Rapid Urease Test ◽  
Diagnostic Reliability ◽  
Predictive Values ◽  
Urease Test ◽  
Stool Samples ◽  
H Pylori ◽  
Good Diagnostic Accuracy ◽  
Sensitivity Specificity

Laboratory-based chemiluminescence immunoassays (CLIA) are widely used in clinical laboratories. Some years ago, a CLIA test was developed for the detection of Helicobacter pylori in stool samples, known as LIAISON H. pylori SA, but little information on its use has been reported. To evaluate the accuracy of the LIAISON H. pylori SA assay for diagnosing H. pylori infection prior to eradication treatment. Diagnostic reliability was evaluated in 252 untreated consecutive patients with dyspepsia. The gold standard for diagnosing H. pylori infection was defined as the concordance of the rapid urease test (RUT), histopathology and urea breath test (UBT). The CLIA assay was performed according to the manufacturer's instructions. Sensitivity, specificity, positive and negative predictive values, and 95% CIs were calculated. According to the gold standard selected, 121 patients were positive for H. pylori infection and 131 negative. LIAISON H. pylori SA had a sensitivity of 90.1% and a specificity of 92.4%, with positive and negative predictive values of 91.6% and 90.1%, respectively. The accuracy of the LIAISON H. pylori SA chemiluminescent diagnostic assay seems comparable to that of ELISA or the best-performing LFIAs. Its sensitivity and specificity, however, seem slightly lower than those of histology, RUT or UBT. The advantages of the assay are that it is cheap, automated, and minimally labor-intensive.

scholarly journals FEV1/FEV6: A Reliable, Easy-to-Use, and Cheaper Alternative to FEV1/FVC in Diagnosing Airway Obstruction in Indian Population

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Anupam Kumar Singh ◽  
Amit Lohia
Keyword(s):  
Airway Obstruction ◽  
Gold Standard ◽  
Indian Population ◽  
Area Under The Curve ◽  
Predictive Values ◽  
Tertiary Centre ◽  
Kappa Value ◽  
Sensitivity Specificity ◽  
Acceptability Criteria ◽  
Indian Data

Background. FEV1/FEV6 has been proposed as a cheap, reproducible and valid alternative to FEV1/FVC in spirometry. No Indian data exists on its utility to diagnose airway obstruction. Aim. we sought to determine a fixed cut off of FEV1/FEV6 to diagnose obstruction corresponding to FEV1/FVC < 0.70 proposed by GOLD guidelines. Method. Spirometry was done on patient referred to a tertiary centre in India. Age, sex, height weight were recorded in addition to spirometric variables like FEV1, FVC, FEV6. The sensitivity, specificity, positive and negative predictive values of FEV1/FEV6 were determined with respect to gold standard of FEV1/FVC < 0.70. Results. 467 spirometries were analysed after meeting the ATS acceptability criteria. Considering FEV1/FVC < 0.7 as being the gold standard for obstruction, ROC curve was used to determine the best corresponding cut-off for FEV1/FEV6. The area under the curve was 99.3% (95% CI: 98.1–99.8%), and the FEV1/FEV6 cut-off, corresponding to the greatest sum of sensitivity and specificity, was 73%. For the total population, the FEV1/FEV6 sensitivity, specificity, PPV, NPV were was 95.7 %, 94.2 %, 87.5 % and 97.9 % respectively. Agreement by Kappa value between two cut offs was excellent 0.89 (0.87–0.91). Conclusion. FEV1/FEV6 < 73% is a new reliable spirometry index to diagnose airway obstruction in Indian population.

scholarly journals Accuracy of a new hysteroscopic method in the assessment of tubal patency: Hysteroscopic Chromotubation

2018 ◽  
Vol 24 (2) ◽  
pp. 82
Author(s):  
Burak Yucel ◽  
Emine Demirel ◽  
Sefa Kelekci ◽  
Kerem Doga Seckin ◽  
Osama Shawki
Keyword(s):  
Methylene Blue ◽  
Cohort Study ◽  
Gold Standard ◽  
Uterine Cavity ◽  
High Sensitivity ◽  
Office Hysteroscopy ◽  
Predictive Values ◽  
Tubal Patency ◽  
Infertile Women ◽  
Sensitivity Specificity

<p><strong>Objective</strong></p><p>The aim of this study was to evaluate the diagnostic accuracy of hysteroscopic chromopertubation (HCT) in the assessment of tubal patency by comparing its results with laparoscopic chromopertubation (LCT).</p><p><strong>Study Design</strong></p><p>The population of this prospective cohort study consisted of both fertile and infertile women. Sixty-four women were included to the study. HCT was assessed by the observation of the transport of highly concentrated methylene blue from uterine cavity to tubal ostia. The results of HCT were compared with the results of LCT as a gold standard. The accuracy of HCT, sensitivity, specificity, positive and negative predictive values in diagnosing tubal patency were calculated.<strong></strong></p><p><strong>Results</strong></p><p>The results of HCT and LCT were evaluated for right and left tubes, separately. One hundred and twenty-eight tubes were determined. Sensitivity, specificity, positive and negative predictive values for HCT were; 85.85%, 59.09%, 91% and 46.43%, respectively.</p><p><strong>Conclusion </strong></p><p>This study’s result showed that HCT had high sensitivity and moderate specificity values in the assessment of tubal patency. HCT during office hysteroscopy could give the chance to practitioners to assess tubal patency without subjecting the patient to multiple procedures.<strong></strong></p>

scholarly journals Validation of maternal recall on exclusive breastfeeding 12 months after childbirth

2020 ◽  
Vol 23 (14) ◽  
pp. 2494-2500
Author(s):  
BC Schneider ◽  
BO Cata-Preta ◽  
DD Gräf ◽  
DLR Silva ◽  
FS Santos ◽  
...  
Keyword(s):  
Birth Cohort ◽  
Exclusive Breastfeeding ◽  
Gold Standard ◽  
Population Based ◽  
Birth Cohort Study ◽  
Predictive Values ◽  
Maternal Report ◽  
Maternal Recall ◽  
Semi Solid ◽  
Sensitivity Specificity

AbstractObjective:We aimed to assess the validity of maternal recall of exclusive breastfeeding (EBF) at 3 months obtained 12 months after childbirth.Design:A population-based birth cohort study. The gold standard is maternal report of EBF at the age of 3 months (yes or no) and age of introduction of other foods in the infant’s diet. EBF was considered when the mother reported that no liquid, semi-solid or solid food was introduced up to that moment. The variable to be validated was obtained at 12 months after childbirth when the mother was asked about the age of food introduction. The prevalence of EBF at 3 months, and sensitivity, specificity, positive (PPV) and negative predictive values (NPV), and accuracy of 12-month recall with 95 % CI were calculated.Setting:Pelotas, Brazil.Participants:3700 mothers of participants of the Pelotas 2004 Birth Cohort.Results:The prevalence of EBF at 3 months was 27·8 % (95 % CI 26·4, 29·3) and 49·0 % (95 % CI 47·4, 50·6) according to gold standard and maternal recall, respectively. The sensitivity of maternal recall at 12 months was 98·3 % (95 % CI 97·4, 99·0), specificity 70·0 % (95 % CI 68·2, 71·7), PPV 55·8 % (95 % CI 53·4, 58·1), NPV 99·1 % (95 % CI 98·6, 99·5) and accuracy 77·9 % (95 % CI 76·6, 79·2). When the analyses were stratified by maternal and infant characteristics, the sensitivity remained around 98 %, and the specificity ranged from 64·4 to 81·8 %.Conclusions:EBF recalled at the end of the first year of infant’s life is a valid measure to be used in epidemiological investigations.

scholarly journals Development and Validation of aPneumocystis jiroveciiReal-time Polymerase Chain Reaction Assay for Diagnosis ofPneumocystisPneumonia

2015 ◽  
Vol 26 (5) ◽  
pp. 263-267 ◽  
Author(s):  
Deirdre L Church ◽  
Anshula Ambasta ◽  
Amanda Wilmer ◽  
Holly Williscroft ◽  
Gordon Ritchie ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Gold Standard ◽  
Pathogenic Fungus ◽  
Immunofluorescence Assay ◽  
Immunocompromised Patients ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Predictive Values ◽  
Sensitivity Specificity

BACKGROUND:Pneumocystis jirovecii(PJ), a pathogenic fungus, causes severe interstitialPneumocystispneumonia (PCP) among immunocompromised patients. A laboratory-developed real-time polyermase chain reaction (PCR) assay was validated for PJ detection to improve diagnosis of PCP.METHODS: Forty stored bronchoalveolar lavage (BAL) samples (20 known PJ positive [PJ+] and 20 known PJ negative [PJ−]) were initially tested using the molecular assay. Ninety-two sequentially collected BAL samples were then analyzed using an immunofluorescence assay (IFA) and secondarily tested using the PJ real-time PCR assay. Discrepant results were resolved by retesting BAL samples using another real-time PCR assay with a different target. PJ real-time PCR assay performance was compared with the existing gold standard (ie, IFA) and a modified gold standard, in which a true positive was defined as a sample that tested positive in two of three methods in a patient suspected to have PCP.RESULTS: Ninety of 132 (68%) BAL fluid samples were collected from immunocompromised patients. Thirteen of 92 (14%) BALs collected were PJ+ when tested using IFA. A total of 40 BAL samples were PJ+ in the present study including: all IFA positive samples (n=13); all referred PJ+ BAL samples (n=20); and seven additional BAL samples that were IFA negative, but positive using the modified gold standard. Compared with IFA, the PJ real-time PCR had sensitivity, specificity, and positive and negative predictive values of 100%, 91%, 65% and 100%, respectively. Compared with the modified gold standard, PJ real-time PCR had a sensitivity, specificity, and positive and negative predictive values of 100%.CONCLUSION: PJ real-time PCR improved detection of PJ in immunocompromised patients.

scholarly journals Comparison of Auramine Phenol and ZN Staining in Diagnosis of Pulmonary Tuberculosis with GeneXpert MTB/RIF as Gold Standard

2020 ◽  
Vol 9 (3) ◽  
pp. 190-194
Author(s):  
Naureen Saeed ◽  
Fatima-tuz-zuhra ◽  
Nadeem Ikram ◽  
Farhana Shaukat ◽  
Fareeha Sardar
Keyword(s):  
Pulmonary Tuberculosis ◽  
Positive Predictive Value ◽  
Predictive Value ◽  
Gold Standard ◽  
Sputum Sample ◽  
False Negative ◽  
Smear Microscopy ◽  
Predictive Values ◽  
Pulmonary Tb ◽  
Sensitivity Specificity

Background: Pakistan faces an immense burden of pulmonary tuberculosis (TB) due to large number of cases and limited resources. Despite the recent advancement in the diagnostic techniques for pulmonary TB, smear microscopy is still a useful technique for the diagnosis of this disease. This study was conducted in order to compare the diagnostic value of Auramine stain with the conventional Ziehl-Neelsen (ZN) stain on the sputum smear for the diagnosis of pulmonary TB, keeping GeneXpert MTB/RIF as the gold standard. Method: This cross-sectional study was conducted on 356 suspected patients of pulmonary TB referred to the Pathology laboratory from TB ward and OPD of District Head Quarter (DHQ) teaching hospital Rawalpindi, Pakistan. Sputum specimen were collected and two smears were prepared from each sputum sample on which Auramine phenol and Ziehl-Neelsen staining were carried out as per WHO recommendations. All these samples were further tested using Gene Xpert MTB/RIF technique. The sensitivity, specificity, Positive predictive value (PPV) and Negative predictive values (NPV) of ZN and Auramine stain were calculated and compared with GeneXpert MTB/RIF technique. Results: Out of the total 356 samples, 64(18%) were positive and 291(82%) were negative by GeneXpert which was taken as the gold standard. On comparison with GeneXpert, percentage of true positive was greater in case of Auramine than ZN stained samples (16.29% versus 12.92%), while the percentage of false positive was same for both staining techniques (0.28%). There were lesser false negative cases observed in samples stained by Auramine as compared to the ones stained by ZN (1.68% versus 5.05%). The sensitivity, specificity, positive predictive value and negative predictive values were 97.87%, 94.17%, 71.88 and 99.66%, respectively for the ZN staining and 98.31%, 97.98%, 90.63% and 99.66% respectively, for the Auramine phenol staining. Conclusion: Smear microscopy using Auramine phenol stain is a useful technique for the diagnosis of pulmonary TB. The Auramine phenol staining with fluorescent microscopy is found to be superior to ZN staining because of higher sensitivity and specificity. Keywords: Auramine phenol, Fluorescence microscopy, GeneXpert, Mycobacterium tuberculosis, Ziehl-Neelsen

Diagnostic Accuracy of Increased Mean Platelet Volume as Inflammatory Marker in Diagnosis of Acute Appendicitis Taking Histopathology as Gold Standard

2021 ◽  
Vol 15 (10) ◽  
pp. 2790-2792
Author(s):  
Hina Rehman Siddiqui ◽  
Tahira Tariq ◽  
Samar Babiker Awadallah Omer ◽  
Nadia Rizvi
Keyword(s):  
Acute Appendicitis ◽  
Diagnostic Accuracy ◽  
Gold Standard ◽  
Mean Platelet Volume ◽  
Inflammatory Marker ◽  
Total Leukocyte Count ◽  
Platelet Volume ◽  
Duration Of Symptoms ◽  
Predictive Values ◽  
Sensitivity Specificity

Objective: To determine diagnostic accuracy of increased mean platelet volume as inflammatory marker in diagnosis of acute appendicitis taking histopathology as gold standard. Study Design: Cross Sectional Study. Setting: Department of Surgery, Abbasi Shaheed Hospital, Karachi. Duration: From 28th October 2016 To 27thApril 2017. Material and Methods: Total 229patients suffered from acute appendicitis were included. Venous blood (<20 ml) for complete blood count was sent to lab before surgery. MPV >11fl was taken as increased value. Post-appendicectomy appendix was sent for histopathology. Sensitivity, specificity, positive and negative predictive values were calculated. Stratification was done. Chi-square test was applied post stratification and p-value ≤0.05 was considered as significant. Results: There were 128 male and 101 female. Mean age was 34.09±6.63 years. Mean duration of symptoms was 28.97±11.89 hours. 107 patients were observed with total leukocyte count >10X103µL. Mean platelets volume was more than 11 fl in 47.2% patients. Sensitivity, Specificity, PPV, NPV and accuracy were 74.6%, 91.6%, 92.5%, 71.9%, and 81.6% respectively. Conclusion: In conclusion in patients with temporary diagnosis of acute appendicitis, high MPV “≥ 11fl” can assist in the identification of acute appendicitis hence negative rate of appendectomy can be decreased.. Keywords: Diagnostic Accuracy, Increased Mean Platelet Volume, Acute Appendicitis, Histopathology

Diagnostic accuracy of current sonographic criteria for the detection of outflow abnormalities in the internal jugular veins

2012 ◽  
Vol 28 (6) ◽  
pp. 285-292 ◽  
Author(s):  
M Simka ◽  
T Ludyga ◽  
P Latacz ◽  
M Kazibudzki
Keyword(s):  
Multiple Sclerosis ◽  
Diagnostic Accuracy ◽  
Doppler Sonography ◽  
Diagnostic Value ◽  
Vascular Pathology ◽  
Reference Test ◽  
Jugular Veins ◽  
Predictive Values ◽  
Sensitivity Specificity ◽  
Internal Jugular Veins

Objectives: This study was aimed at evaluation of the diagnostic value of Doppler sonography for the assessment of abnormalities in the internal jugular veins (IJVs). Method: One hundred and sixteen IJVs were assessed in 58 patients with associated multiple sclerosis. Findings of Doppler sonography were compared with results of the reference test: catheter venography. Results: At least one positive extracranial sonographic criterion suggesting venous abnormality was found in 92.2% of the assessed veins. Yet, sensitivity, specificity, positive and negative predictive values of sonography were low: 93.4%, 12.0%, 79.4% and 33.3% for at least one positive criterion, and for at least two positive criteria: 29.3%, 75.0%, 81.8% and 21.7%, respectively. Conclusions: Our research has shown that currently used extracranial sonographic criteria for the detection of obstructive venous abnormalities in the IJVs are of limited diagnostic value. For the time being, diagnosis of this vascular pathology should be given using catheter venography.

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