The Experts below are selected from a list of 28410 Experts worldwide ranked by ideXlab platform
I. U. H. Mian - One of the best experts on this subject based on the ideXlab platform.
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Maximum likelihood estimation of the Kappa Coefficient from bivariate logistic regression.
Statistics in Medicine, 1996Co-Authors: Mohamed Shoukri, I. U. H. MianAbstract:We propose a maximum likelihood estimator (MLE) of the Kappa Coefficient from a 2 x 2 table when the binary ratings depend on patient and/or clinician effects. We achieve this by expressing the logit of the probability of positive rating as a linear function of the subject-specific and the rater-specific covariates. We investigate the bias and variance of the MLE in small and moderate size samples through Monte Carlo simulation and we provide the sample size calculation to detect departure from the null hypothesis H0: Kappa = Kappa 0 in the direction of H1: Kappa > Kappa 0.
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maximum likelihood estimation of the Kappa Coefficient from models of matched binary responses
Statistics in Medicine, 1995Co-Authors: Mohamed Shoukri, S W Martin, I. U. H. MianAbstract:We present an estimate of the Kappa-Coefficient of agreement between two methods of rating based on matched pairs of binary responses and show that the estimate depends on the common intraclass correlation Coefficient between the pairs. Via Monte Carlo simulation, we investigate power of the test of significance on Kappa, and the large sample bias and variance of its maximum likelihood estimator.
Mohamed Shoukri - One of the best experts on this subject based on the ideXlab platform.
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Maximum likelihood estimation of the Kappa Coefficient from bivariate logistic regression.
Statistics in Medicine, 1996Co-Authors: Mohamed Shoukri, I. U. H. MianAbstract:We propose a maximum likelihood estimator (MLE) of the Kappa Coefficient from a 2 x 2 table when the binary ratings depend on patient and/or clinician effects. We achieve this by expressing the logit of the probability of positive rating as a linear function of the subject-specific and the rater-specific covariates. We investigate the bias and variance of the MLE in small and moderate size samples through Monte Carlo simulation and we provide the sample size calculation to detect departure from the null hypothesis H0: Kappa = Kappa 0 in the direction of H1: Kappa > Kappa 0.
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maximum likelihood estimation of the Kappa Coefficient from models of matched binary responses
Statistics in Medicine, 1995Co-Authors: Mohamed Shoukri, S W Martin, I. U. H. MianAbstract:We present an estimate of the Kappa-Coefficient of agreement between two methods of rating based on matched pairs of binary responses and show that the estimate depends on the common intraclass correlation Coefficient between the pairs. Via Monte Carlo simulation, we investigate power of the test of significance on Kappa, and the large sample bias and variance of its maximum likelihood estimator.
John M Mazur - One of the best experts on this subject based on the ideXlab platform.
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interobserver reliability and intraobserver reproducibility of the system of king et al for the classification of adolescent idiopathic scoliosis
Journal of Bone and Joint Surgery American Volume, 1998Co-Authors: R J Cummings, E A Loveless, S Samelson, J. Campbell, John M MazurAbstract:The classification of adolescent idiopathic scoliosis with use of the system of King et al. has become widely accepted since its introduction. The purpose of the present study was to establish the interobserver reliability and intraobserver reproducibility of this classification system. The preoperative radiographs of sixty-three patients who were managed operatively for adolescent idiopathic scoliosis were classified by five observers with the system of King et al. Interobserver reliability was assessed by comparison of the classification of the curves among the observers, and intraobserver reproducibility was evaluated by comparison of the classifications of each set of radiographs by each observer on two occasions three weeks apart. The median interobserver reliability Kappa Coefficient for the classification system of King et al. was 0.44 (range, 0.28 to 0.50), and the median intraobserver reproducibility Kappa Coefficient was 0.64 (range, 0.44 to 0.72). According to the definition of Landis and Koch, the classification system of King et al. is substantially reproducible but is only moderately reliable. However, according to the stricter definition of Svanholm et al., its reproducibility is only fair and its reliability is poor.
Mufei Li - One of the best experts on this subject based on the ideXlab platform.
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Serial testing of Mycobacterium tuberculosis infection in Chinese village doctors by QuantiFERON-TB Gold Plus, QuantiFERON-TB Gold in-Tube and T-SPOT.TB
Journal of Infection, 2019Co-Authors: Haoran Zhang, Dakuan Wang, Jinxing Wang, Xiangwei Li, Boxuan Feng, Mufei LiAbstract:Summary Objectives To evaluate the performance of QuantiFERON-TB Gold Plus (QFT-Plus) on Mycobacterium tuberculosis (MTB) infection test among registered village doctors from China. Methods MTB infection of the registered village doctors in Zhongmu County were tested using QFT-Plus and two other interferon-gamma release assays (IGRAs) in parallel: QuantiFERON-TB Gold In-Tube (QFT) and T-SPOT.TB (T-SPOT). Retests were carried out for baseline positives at 3 and 6 months later, respectively. Results A total of 616 village doctors were included in the baseline examination. The positivity of QFT, QFT-Plus and T-SPOT was 27.91% (168/602), 31.22% (187/599) and 27.70% (169/610), respectively. The concordance between QFT and QFT-Plus was 94.81% (Kappa Coefficient: 0.87) and between T-SPOT and QFT-Plus was 88.93% (Kappa Coefficient: 0.73). Reversions were frequently observed for all three assays. With respect to QFT-Plus, the quantitative results of reversions in the serial testing were mostly distributed in an “uncertain range” zone (0.2-0.7 IU/mL). Similar patterns of distribution were observed for QFT and T-SPOT as well. Conclusion Village doctors should gain more attention as an at-risk group for TB infection control in rural China. Our results support, by means of serial testing, a good agreement between QFT-Plus and QFT in Chinese population.
Jose Luis Lazaromartinez - One of the best experts on this subject based on the ideXlab platform.
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respond to the letter on interobserver reliability of the ankle brachial index toe brachial index and distal pulse palpation in patients with diabetes a methodological issue
Diabetes and Vascular Disease Research, 2018Co-Authors: Francisco Javier Alvaro Afonso, Esther Garciamorales, Raul Juan Molinesbarroso, Yolanda Garciaalvarez, Irene Sanzcorbalan, Jose Luis LazaromartinezAbstract:We respond to the letter of Nadery and Shahsavari regarding our paper entitled 'Interobserver reliability of the ankle brachial index, toe -brachial index and distal pulse palpation in patients with diabetes. In this letter, we concluded that despite some limitations, the Kappa Coefficient is an informative measure of agreement in most circumstances that we can use in this type of clinical research.