In survival data analysis, the proportional hazards (PH), accelerated failure time(AFT), and proportional odds (PO) models are commonly used semiparametric models forthe comparison of survivability in subjects. These models assume that the survival curvesdo not cross. However, in some clinical...

In many clinical studies, researchers are interested in theeffects of a set of prognostic factors on the hazard of death from a specific disease even though patients may die from other competing causes. Often the time to relapse is right-censored for some individuals due to incomplete follow-up....

The accelerated failure time (AFT) model is a popular model for time-to-event data. It provides a useful alternative when the proportional hazards assumption is in question and it provides an intuitive linear regression interpretation where the logarithm of the survival time is regressed on the...

In many longitudinal studies, it is of interest to characterize the relationship between a time-to-event (e.g. survival) and time-dependent and time-independent covariates. Time-dependent covariates are generally observed intermittently and with error.For a single time-dependent covariate, a...

In longitudinal studies, data are often missing despite every attempt made to collect complete data. When the missingness is informative and hence not ignorable, it is generally difficult to analyze non-ignorable missing (NIM) data since the distributional assumptions about missing data are not...

Count data with excess zeros are commonly seen in experiments forimproving electronics manufacturing quality, in medical researchof HIV patients with high-risk behaviors and in agricultural study of number of insects per leaf.Yip (1988) and Lambert (1992) proposed zero-inflated Poisson...

The application of the bootstrap to spatially correlated data has not been studied as widely as its application to time series data. This is a challenging problem since it is difficult to preserve the correlation structure of the data while implementing the bootstrap method. Kunsch (1989),...