3 documents found, page 1 of 1
Estimation of the bivariate distribution function for censored gap times
Moreira, Ana Cristina; Araújo, Artur Agostinho; Machado, Luís MeiraIn many medical studies, patients may experience several events during follow-up. The times between consecutive events (gap times) are often of interest and lead to problems that have received much attention recently. In this work we consider the estimation of the bivariate distribution function for censored gap times. Some related problems such as the estimation of the marginal distribution of the second gap t...
smoothHR: an R package for pointwise nonparametric estimation of hazard ratio c...
Machado, Luís Meira; Cadarso-Suárez, Carmen; Gude, Francisco; Araújo, Artur AgostinhoThe Cox proportional hazards regression model has become the traditional choice for modeling survival data in medical studies. Usually, this model is assumed to be (semi)parametric, and the effects of continuous predictors on log-hazards are modeled linearly. In practice, however, the effect of a given continuous predictor can be unknown. To introduce flexibility into the Cox model, several smoothing methods ma...
Estimation of the bivariate distribution function: a comparative study
Moreira, Ana Cristina; Araújo, Artur Agostinho; Machado, Luís MeiraLet (X,T) be a random vector where the response variable T denotes a lifetime, which is subject to random right censoring, and X denotes a covariate. In this paper we compare several estimators for the bivariate distribution of (X,T) through a simulation study. The methods are applied to bone marrow transplant data where we use one qualitative predictor. The proposed estimators can be applied to ROC curves for ...