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Full-Text Articles in Survival Analysis
Confidence Intervals In Survival Analysis, Tan Shay Kee
Confidence Intervals In Survival Analysis, Tan Shay Kee
Student Works (2010-2019)
In obtaining confidence interval for the survivor function using Greenwood’s formula and in performing log-rank test for comparing the survivor functions of two groups of individuals, only the information given by the first two moments of the relevant statistics are used. Presently we show that by incorporating the information given by the third and fourth moments of the statistics, the performance of the confidence interval and statistical test can be improved. When the survivor function can be described by the Weibull distribution, the knowledge regarding the survivor function can be obtained through the estimation of the Weibull scale and shape …
Detecting Outliers And Influential Observations In Survival Model., Nor Akmal Md Noh
Detecting Outliers And Influential Observations In Survival Model., Nor Akmal Md Noh
Student Works (2010-2019)
This study proposes outlier and influential observation detection procedures for Cox proportional hazard model. In the estimation process, the parameters for Cox proportional hazard model are estimated using partial likelihood method, while the baseline hazard estimates are obtained using Nelson-Aalen method. The procedure of outlier detection is based on three types of residuals; deviance, log-odd and normal deviate residuals. We study their properties and compare their performance in detecting outliers via simulation. On the other hand, we propose a procedure of identifying influential observation using forward search method. The method has been shown to be effective in detecting influential observations …