Estimation of the confidence interval for the difference between two median survival times under a gamma frailty model

• Main Authors: Chen, Kuan-Ming, 陳冠銘
• Other Authors: Chang, Yu-Mei
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/76147658128152619862

碩士 === 東海大學 === 統計學系 === 101 === In medical medicine studies, we often evaluate the effect of two drugs according to the difference of median survival time between two groups of patients. When the data are from the clinical trials with long term follow-up, the treatment effect diminishes as time progresses. Thus, the proportional hazards assumption may be violated. To account for variability due to unobserved factors, we consider the confidence interval for the difference between two median survival times under a gamma frailty model by extending the Su and Wei (1993) method. The associated coverage probability and the average length of the interval will be evaluated via a simulation study. The implementation of the proposed confidence interval will be illustrated with a real data set.