Hui and Walter's latent-class reference-free approach may be more useful in assessing agreement than diagnostic performance

2005 ◽  
Vol 58 (7) ◽  
pp. 688-700 ◽  
Author(s):  
Philippe Bertrand ◽  
Jacques Bénichou ◽  
Philippe Grenier ◽  
Claude Chastang
Keyword(s):  
Diagnostic Performance ◽  
Latent Class ◽  
Class Reference

scholarly journals Diagnostic performance of a commercial ELISA used as a complementary test for bovine tuberculosis in two bovine herds with different disease status

2020 ◽  
Vol 72 (1) ◽  
pp. 1-8
Author(s):  
P.M. Soares Filho ◽  
A.K. Ramalho ◽  
A.M. Silva ◽  
M.A. Issa ◽  
P.M.P.C. Mota ◽  
...  
Keyword(s):  
Bovine Tuberculosis ◽  
Diagnostic Performance ◽  
Latent Class ◽  
Serological Test ◽  
Antibody Test ◽  
Latent Class Models ◽  
Lower Sensitivity ◽  
Kappa Index ◽  
Serological Tests ◽  
Test Kit

ABSTRACT Bovine tuberculosis is a worldwide spread zoonotic disease. Intradermal tuberculinizations are the most used diagnostic tests in the world. Serological tests can be an ancillary diagnosis for bovine tuberculosis. The objective of this study was to evaluate the diagnostic performance of the ELISA Mycobacterium Bovis Antibody Test Kit IDEXX ™ in infected herds, which were in different disease control stages. One hundred and twenty animals from two dairy herds of Minas Gerais state, Brazil, were subjected to the ELISA serological test and the comparative cervical tuberculin test (CCT). Diagnostic test parameters were estimated using Bayesian latent class models and concordance between tests estimated by the frequentist approach. The ELISA test presented lower sensitivity than CCT in both herds. Its sensitivity was higher in the herd in sanitation process. Specificity estimates were above 95% in both herds. Kappa index indicated low concordance or even disagreement between tests. According to the results, the ELISA IDEXX should not be used as substitution for CCT. The tests must not be associated in series. Parallel association increased diagnostic sensitivity in the herd which was in the process of sanitation.

scholarly journals Cross-Reactivity Using Chimeric Trypanosoma cruzi Antigens: Diagnostic Performance in Settings Where Chagas Disease and American Cutaneous or Visceral Leishmaniasis Are Coendemic

2019 ◽  
Vol 57 (8) ◽  
Author(s):  
Ramona Tavares Daltro ◽  
Leonardo Maia Leony ◽  
Natália Erdens Maron Freitas ◽  
Ângelo Antônio Oliveira Silva ◽  
Emily Ferreira Santos ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Chagas Disease ◽  
Diagnostic Performance ◽  
Latent Class ◽  
Cross Reactivity ◽  
Chimeric Proteins ◽  
Serum Samples ◽  
Perfect Agreement ◽  
Content Type ◽  
Chronic Chagas Disease

ABSTRACT Chimeric T. cruzi antigens have been proposed as a diagnostic tool for chronic Chagas disease (CD) in both settings where Chagas disease is endemic and those where it is not endemic. Antibody response varies in accordance to each T. cruzi strain, presenting challenges to the use of antigens lacking demonstrated cross-reactivity with Leishmania spp. Our group expressed four chimeric proteins (IBMP-8.1, IBMP-8.2, IBMP-8.3, and IBMP-8.4) and previously assessed their diagnostic performance to determine cross-reactivity with Leishmania spp. Here, we validated our findings using serum samples from different Brazilian geographic areas reporting endemic Chagas disease, endemic visceral or American cutaneous leishmaniasis (ACL), or both. Overall, 829 serum samples were evaluated using commercial and IBMP enzyme-linked immunosorbent assays. Due to the absence of a reference assay to diagnosis CD, latent class analysis (LCA) was performed through the use of a statistical model. The incidence of cross-reactivity for ACL-positive samples varied from 0.35% (IBMP-8.3) to 0.70% (IBMP-8.1 and IBMP-8.2). Regarding visceral leishmaniasis (VL)-positive samples, the IBMP-8.2 and IBMP-8.3 antigens cross-reacted with six (3.49%) and with only one sample (0.58%), respectively. No cross-reactivity with either ACL or VL was observed for the IBMP-8.4 antigen. Similarly, no cross-reactions were found when VL-positive samples were assayed with IBMP-8.1. The agreement among the results obtained using IBMP antigens ranged from 97.3% for IBMP-8.2 and 99% for IBMP-8.1 and IBMP-8.3 to 100% for IBMP-8.4, demonstrating almost perfect agreement with LCA. Accordingly, in light of the negligible cross-reactivity with both ACL and VL, we suggest the use of IBMP antigens in regions where T. cruzi and Leishmania spp. are coendemic.

scholarly journals Diagnostic Performance Tests for Suspected Scaphoid Fractures Differ with Conventional and Latent Class Analysis

2011 ◽  
Vol 469 (12) ◽  
pp. 3400-3407 ◽  
Author(s):  
Geert A. Buijze ◽  
Wouter H. Mallee ◽  
Frank J. P. Beeres ◽  
Timothy E. Hanson ◽  
Wesley O. Johnson ◽  
...  
Keyword(s):  
Latent Class Analysis ◽  
Diagnostic Performance ◽  
Latent Class ◽  
Performance Tests ◽  
Class Analysis ◽  
Scaphoid Fractures

scholarly journals Better than we thought? The diagnostic performance of an influenza point-of-care test in children, a Bayesian re-analysis

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 53
Author(s):  
Joseph Lee
Keyword(s):  
Diagnostic Accuracy ◽  
Influenza A ◽  
Diagnostic Performance ◽  
Latent Class ◽  
Point Of Care ◽  
Credible Interval ◽  
Latent Class Models ◽  
Rt Pcr ◽  
Point Of Care Test ◽  
Low Sensitivity

Background: Point-of-care tests (POCTs) for influenza have been criticised for their diagnostic accuracy, with clinical use limited by low sensitivity. These criticisms are based on diagnostic-accuracy studies that often use the questionable assumption of an infallible gold standard. Bayesian latent class modelling can estimate diagnostic performance without this assumption. Methods: Data extracted from published diagnostic-accuracy studies comparing the QuickVue® influenza A+B influenza POCT to reverse-transcriptase polymerase chain reaction (RT-PCR) in two different populations were re-analysed. Classical and Bayesian latent class methods were applied using the Modelling for Infectious diseases CEntre (MICE) web-based application. Results: Under classical analyses the estimated sensitivity and specificity of the QuickVue® were 66.9% (95% confidence interval (CI) 61.4-71.9) and 97.8% (95% CI 95.7-98.9), respectively. Bayesian latent class models estimated sensitivity of 97.8% (95% credible interval (CrI) 82.1-100) and specificity of 98.5% (95% CrI 96.5-100). Conclusions: Data from studies comparing the QuickVue® point-of-care test to RT-PCR are compatible with better diagnostic performance than previously reported.

scholarly journals Predicting Frailty and Geriatric Interventions in Older Cancer Patients: Performance of Two Screening Tools for Seven Frailty Definitions—ELCAPA Cohort

Cancers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 244
Author(s):  
Claudia Martinez-Tapia ◽  
Marie Laurent ◽  
Elena Paillaud ◽  
Philippe Caillet ◽  
Emilie Ferrat ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Diagnostic Performance ◽  
Latent Class ◽  
Task Force ◽  
Characteristic Curve ◽  
Frailty Index ◽  
Geriatric Oncology ◽  
Reference Standards ◽  
Screening Tools ◽  
Geriatric Intervention

Screening tools have been developed to identify patients warranting a complete geriatric assessment (GA). However, GA lacks standardization and does not capture important aspects of geriatric oncology practice. We measured and compared the diagnostic performance of screening tools G8 and modified G8 according to multiple clinically relevant reference standards. We included 1136 cancer patients ≥ 70 years old referred for GA (ELCAPA cohort; median age, 80 years; males, 52%; main locations: digestive (36.3%), breast (16%), and urinary tract (14.8%); metastases, 43.5%). Area under the receiver operating characteristic curve (AUROC) estimates were compared between both tools against: (1) the detection of ≥1 or (2) ≥2 GA impairments, (3) the prescription of ≥1 geriatric intervention and the identification of an unfit profile according to (4) a latent class typology, expert-based classifications from (5) Balducci, (6) the International Society of Geriatric Oncology task force (SIOG), or using (7) a GA frailty index according to the Rockwood accumulation of deficits principle. AUROC values were ≥0.80 for both tools under all tested definitions. They were statistically significantly higher for the modified G8 for six reference standards: ≥1 GA impairment (0.93 vs. 0.89), ≥2 GA impairments (0.90 vs. 0.87), ≥1 geriatric intervention (0.85 vs. 0.81), unfit according to Balducci (0.86 vs. 0.80) and SIOG classifications (0.88 vs. 0.83), and according to the GA frailty index (0.86 vs. 0.84). Our findings demonstrate the robustness of both screening tools against different reference standards, with evidence of better diagnostic performance of the modified G8.

scholarly journals Diagnostic Performance of Various Tests and Criteria Employed in Allergic Bronchopulmonary Aspergillosis: A Latent Class Analysis

PLoS ONE ◽  
2013 ◽  
Vol 8 (4) ◽  
pp. e61105 ◽  
Author(s):  
Ritesh Agarwal ◽  
Dipesh Maskey ◽  
Ashutosh Nath Aggarwal ◽  
Biman Saikia ◽  
Mandeep Garg ◽  
...  
Keyword(s):  
Latent Class Analysis ◽  
Diagnostic Performance ◽  
Latent Class ◽  
Allergic Bronchopulmonary Aspergillosis ◽  
Class Analysis

Zur Anwendung der CES-D bei älteren Menschen: Dimensionsstruktur und Meßartefakte

Diagnostica ◽  
2000 ◽  
Vol 46 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Herbert Matschinger ◽  
Astrid Schork ◽  
Steffi G. Riedel-Heller ◽  
Matthias C. Angermeyer
Keyword(s):  
Mental State ◽  
Latent Class ◽  
Mini Mental State Examination ◽  
Depression Scale ◽  
Epidemiological Studies ◽  
Partial Credit ◽  
Examination Score ◽  
State Examination

Zusammenfassung. Beim Einsatz der Center for Epidemiological Studies Depression Scale (CES-D) stellt sich das Problem der Dimensionalität des Instruments, dessen Lösung durch die Konfundierung eines Teilkonstruktes (“Wohlbefinden”) mit Besonderheiten der Itemformulierung Schwierigkeiten bereitet, da Antwortartefakte zu erwarten sind. Dimensionsstruktur und Eignung der CES-D zur Erfassung der Depression bei älteren Menschen wurden an einer Stichprobe von 663 über 75-jährigen Teilnehmern der “Leipziger Langzeitstudie in der Altenbevölkerung” untersucht. Da sich die Annahme der Gültigkeit eines partial-credit-Rasch-Modells sowohl für die Gesamtstichprobe als auch für eine Teilpopulation als zu restriktiv erwies, wurde ein 3- bzw. 4-Klassen-latent-class-Modell für geordnete Kategorien berechnet und die 4-Klassen-Lösung als den Daten angemessen interpretiert: Drei Klassen zeigten sich im Sinne des Konstrukts “Depression” geordnet, eine Klasse enthielt jene Respondenten, deren Antwortmuster auf ein Antwortartefakt hinwiesen. In dieser Befragtenklasse wird der Depressionsgrad offensichtlich überschätzt. Zusammenhänge mit Alter und Mini-Mental-State-Examination-Score werden dargestellt. Nach unseren Ergebnissen muß die CES-D in einer Altenbevölkerung mit Vorsicht eingesetzt werden, der Summenscore sollte nicht verwendet werden.

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