Estimating concordance correlation coefficients by variance components for longitudinal Poisson data
| Autor: | Chiu,Ying-Lin, 邱瑩琳 |
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| Rok vydání: | 2018 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 106 The concordance correlation coefficient (CCC) is an indice that can measure the agreement between observers. In the past, the classical concordance correlation coefficient is applied to measure the agreement between two observers with continuous data. However, it is common that we need to assess the agreement among multiple observers for discrete responses in clinical research. In this paper, we introduce how to use a variance components (VC) method to assess the agreement among multiple observers for countable replicated readings. We assume that under a three-way generalized linear mixed model, the subject effect, the subject-by-observer interaction effect and the subject-by-time interaction effect are assumed as random effects, while the observer effect, the time effect and the observer-by-time interaction are assumed to be fixed. In the simulation studies, we use the VC approach to assess the intra- and inter- and total-CCCs and compare the performance of VC and U-Statistics (US) methods. It is concluded that no matter what sample size is used, the mean square errors of VC are smaller than those of US, and the 95% coverage rates of VC remain at the nominal coverage. Finally, an application of reproducibility of corticospinal diffusion tensor tractography study is illustrated. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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