scholarly journals Conditional estimation of sensitivity and specificity from a phase 2 biomarker study allowing early termination for futility

2008 ◽  
Vol 28 (5) ◽  
pp. 762-779 ◽  
Author(s):  
Margaret Sullivan Pepe ◽  
Ziding Feng ◽  
Gary Longton ◽  
Joseph Koopmeiners
Keyword(s):  
Sensitivity And Specificity ◽  
Early Termination ◽  
Phase 2 ◽  
Conditional Estimation

scholarly journals Multicenter Noninferiority Evaluation of Hain GenoType MTBDRplusVersion 2 and Nipro NTM+MDRTB Line Probe Assays for Detection of Rifampin and Isoniazid Resistance

2016 ◽  
Vol 54 (6) ◽  
pp. 1624-1630 ◽  
Author(s):  
Ruvandhi R. Nathavitharana ◽  
Doris Hillemann ◽  
Samuel G. Schumacher ◽  
Birte Schlueter ◽  
Nazir Ismail ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Phase 1 ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Drug Susceptibility Testing ◽  
Phase 2 ◽  
Reference Standard ◽  
Two Phase ◽  
Mdr Tb ◽  
Resistance Detection

Less than 30% of multidrug-resistant tuberculosis (MDR-TB) patients are currently diagnosed, due to laboratory constraints. Molecular diagnostics enable rapid and simplified diagnosis. Newer-version line probe assays have not been evaluated against the WHO-endorsed Hain GenoType MTBDRplus(referred to as Hain version 1 [V1]) for the rapid detection of rifampin (RIF) and isoniazid (INH) resistance. A two-phase noninferiority study was conducted in two supranational reference laboratories to allow head-to-head comparisons of two new tests, Hain Genotype MTBDRplusversion 2 (referred to as Hain version 2 [V2]) and Nipro NTM+MDRTB detection kit 2 (referred to as Nipro), to Hain V1. In phase 1, the results for 379 test strains were compared to a composite reference standard that used phenotypic drug susceptibility testing (DST) and targeted sequencing. In phase 2, the results for 644 sputum samples were compared to a phenotypic DST reference standard alone. Using a challenging set of strains in phase 1, the values for sensitivity and specificity for Hain V1, Hain V2, and Nipro, respectively, were 90.3%/98.5%, 90.3%/98.5%, and 92.0%/98.5% for RIF resistance detection and 89.1%/99.4%, 89.1%/99.4%, and 89.6%/100.0% for INH resistance detection. Testing of sputa in phase 2 yielded values for sensitivity and specificity of 97.1%/97.1%, 98.2%/97.8%, and 96.5%/97.5% for RIF and 94.4%/96.4%, 95.4%/98.8%, and 94.9%/97.6% for INH. Overall, the rates of indeterminate results were low, but there was a higher rate of indeterminate results with Nipro than with Hain V1 and V2 in samples with low smear grades. Noninferiority of Hain V2 and Nipro to Hain V1 was demonstrated for RIF and INH resistance detection in isolates and sputum specimens. These results serve as evidence for WHO policy recommendations on the use of line probe assays, including the Hain V2 and Nipro assays, for MDR-TB detection.

scholarly journals Conditional estimation after a two-stage diagnostic biomarker study that allows early termination for futility

2012 ◽  
Vol 31 (5) ◽  
pp. 420-435 ◽  
Author(s):  
Joseph S. Koopmeiners ◽  
Ziding Feng ◽  
Margaret Sullivan Pepe
Keyword(s):  
Early Termination ◽  
Diagnostic Biomarker ◽  
Two Stage ◽  
Conditional Estimation

scholarly journals Prediction of anemia and estimation of hemoglobin concentration using a smartphone camera

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0253495
Author(s):  
Selim Suner ◽  
James Rayner ◽  
Ibrahim U. Ozturan ◽  
Geoffrey Hogan ◽  
Caroline P. Meehan ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Phase 1 ◽  
Region Of Interest ◽  
Hemoglobin Concentration ◽  
Phase 2 ◽  
Convenience Sample ◽  
Palpebral Conjunctiva ◽  
Phase Images ◽  
Academic Teaching Hospital ◽  
Using Data

Anemia, defined as a low hemoglobin concentration, has a large impact on the health of the world’s population. We describe the use of a ubiquitous device, the smartphone, to predict hemoglobin concentration and screen for anemia. This was a prospective convenience sample study conducted in Emergency Department (ED) patients of an academic teaching hospital. In an algorithm derivation phase, images of both conjunctiva were obtained from 142 patients in Phase 1 using a smartphone. A region of interest targeting the palpebral conjunctiva was selected from each image. Image-based parameters were extracted and used in stepwise regression analyses to develop a prediction model of estimated hemoglobin (HBc). In Phase 2, a validation model was constructed using data from 202 new ED patients. The final model based on all 344 patients was tested for accuracy in anemia and transfusion thresholds. Hemoglobin concentration ranged from 4.7 to 19.6 g/dL (mean 12.5). In Phase 1, there was a significant association between HBc and laboratory-predicted hemoglobin (HBl) slope = 1.07 (CI = 0.98–1.15), p<0.001. Accuracy, sensitivity, and specificity of HBc for predicting anemia was 82.9 [79.3, 86.4], 90.7 [87.0, 94.4], and 73.3 [67.1, 79.5], respectively. In Phase 2, accuracy, sensitivity and specificity decreased to 72.6 [71.4, 73.8], 72.8 [71, 74.6], and 72.5 [70.8, 74.1]. Accuracy for low (<7 g/dL) and high (<9 g/dL) transfusion thresholds was 94.4 [93.7, 95] and 86 [85, 86.9] respectively. Error trended with increasing HBl values (slope 0.27 [0.19, 0.36] and intercept -3.14 [-4.21, -2.07] (p<0.001) such that HBc tended to underestimate hemoglobin in higher ranges and overestimate in lower ranges. Higher quality images had a smaller bias trend than lower quality images. When separated by skin tone results were unaffected. A smartphone can be used in screening for anemia and transfusion thresholds. Improvements in image quality and computational corrections can further enhance estimates of hemoglobin.

Applying Item Response Theory Modeling to Identify Social (Pragmatic) Communication Disorder

2020 ◽  
Vol 63 (6) ◽  
pp. 1916-1932 ◽  
Author(s):  
Haiying Yuan ◽  
Christine Dollaghan
Keyword(s):  
Item Response Theory ◽  
Item Response ◽  
Sensitivity And Specificity ◽  
Social Communication ◽  
National Database ◽  
Communication Disorder ◽  
Social Communication Questionnaire ◽  
Autism Research ◽  
The Social ◽  
Pragmatic Communication

Purpose No diagnostic tools exist for identifying social (pragmatic) communication disorder (SPCD), a new Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition category for individuals with social communication deficits but not the repetitive, restricted behaviors and interests (RRBIs) that would qualify them for a diagnosis of autism spectrum disorder (ASD). We explored the value of items from a widely used screening measure of ASD for distinguishing SPCD from typical controls (TC; Aim 1) and from ASD (Aim 2). Method We applied item response theory (IRT) modeling to Social Communication Questionnaire–Lifetime ( Rutter, Bailey, & Lord, 2003 ) records available in the National Database for Autism Research. We defined records from putative SPCD ( n = 54), ASD ( n = 278), and TC ( n = 274) groups retrospectively, based on National Database for Autism Research classifications and Autism Diagnostic Interview–Revised responses. After assessing model assumptions, estimating model parameters, and measuring model fit, we identified items in the social communication and RRBI domains that were maximally informative in differentiating the groups. Results IRT modeling identified a set of seven social communication items that distinguished SPCD from TC with sensitivity and specificity > 80%. A set of five RRBI items was less successful in distinguishing SPCD from ASD (sensitivity and specificity < 70%). Conclusion The IRT modeling approach and the Social Communication Questionnaire–Lifetime item sets it identified may be useful in efforts to construct screening and diagnostic measures for SPCD.

IgA-antitissue transglutaminase: Sensitivity and specificity for diagnosing Celiac Disease

2001 ◽  
Vol 120 (5) ◽  
pp. A395-A395
Author(s):  
J WEST ◽  
A LLOYD ◽  
P HILL ◽  
G HOLMES
Keyword(s):  
Celiac Disease ◽  
Sensitivity And Specificity

Rationalization and internalization

2001 ◽  
Vol 60 (4) ◽  
pp. 215-230 ◽  
Author(s):  
Jean-Léon Beauvois
Keyword(s):  
Phase 1 ◽  
Facilitatory Effect ◽  
Phase 2 ◽  
Causal Explanations ◽  
Reduction Effect ◽  
Dissonance Reduction

After having been told they were free to accept or refuse, pupils aged 6–7 and 10–11 (tested individually) were led to agree to taste a soup that looked disgusting (phase 1: initial counter-motivational obligation). Before tasting the soup, they had to state what they thought about it. A week later, they were asked whether they wanted to try out some new needles that had supposedly been invented to make vaccinations less painful. Agreement or refusal to try was noted, along with the size of the needle chosen in case of agreement (phase 2: act generalization). The main findings included (1) a strong dissonance reduction effect in phase 1, especially for the younger children (rationalization), (2) a generalization effect in phase 2 (foot-in-the-door effect), and (3) a facilitatory effect on generalization of internal causal explanations about the initial agreement. The results are discussed in relation to the distinction between rationalization and internalization.

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