Interval estimations for parameters of gompertz model with time-dependent covariate and right censored data

摘要

There are numerous parametric models for analyzing survival data such as exponential, Weibull, log-normal and gamma.udOne of such models is the Gompertz model which is widely used in biology and demography. Most of these models areudextended to new forms for accommodating different types of censoring mechanisms and different types of covariates. Inudthis paper the performance of the Gompertz model with time-dependent covariate in the presence of right censored dataudwas studied. Moreover, the performance of the model was compared at different censoring proportions (CP) and sampleudsizes. Also, the model was compared with fixed covariate model. In addition, the effect of fitting a fixed covariate modeludwrongly to a data with time-dependent covariate was studied. Finally, two confidence interval estimation techniques,udWald and jackknife, were applied to the parameters of this model and the performance of the methods was compared.