Type of Document Master's Thesis Author Zhou, Haochuan URN etd-07182008-160250 Title NEW NON-PARAMETRIC CONFIDENCE INTERVAL FOR THE YOUDEN Degree Master of Science Department Mathematics and Statistics Advisory Committee
Advisor Name Title Gengsheng Qin Committee Chair Yixin Fang Committee Member Yu-sheng Hsu Committee Member Keywords
- Confidence intervals
- Optimal cut-point
- ROC curve
- Specificity
- Sensitivity
- Youden index
Date of Defense 2008-07-17 Availability unrestricted Abstract Youden index, a main summary index for the Receiver Operating Characteristic (ROC) curve, is a comprehensive measurement for the effectiveness of a diagnostic test. For a continuous-scale diagnostic test, the optimal cut-point for the positive of disease is the cut-point leading to the maximization of the sum of sensitivity and specificity. Finding the Youden index of the test is equivalent to maximize the sum of sensitivity and specificity for all the possible values of the cut-point. In this thesis, we propose a new non-parametric confidence interval for the Youden index. Extensive simulation studies are conducted to compare the relative performance of the new interval with the existing intervals for the index. Our simulation results indicate that the newly developed non-parametric method performs as well as the existing parametric method but it has better finite sample performance than the existing non-parametric methods. The new method is flexible and easy to implement in practice. A real example is also used to illustrate the application of the proposed interval.Files
Filename Size Approximate Download Time (Hours:Minutes:Seconds)
28.8 Modem 56K Modem ISDN (64 Kb) ISDN (128 Kb) Higher-speed Access Zhou_Harris_MS_2008.pdf 357.89 Kb 00:01:39 00:00:51 00:00:44 00:00:22 00:00:01