Survival models with a frailty term are presented as an extension of Cox's proportional risk model (COX, 1972), in which a random effect, called frailty, is introduced in the risk function in a multiplicative way with the ...

Frailty models are generally used to model heterogeneity and dependence between individuals. The distribution of the frailty variable is often assumed to be continuous. However, there are situations where a discretely-distributed ...

Frailty models are used for modeling heterogeneity in the data analysis of lifetimes. Analysis that ignore frailty when it is present leads to incorrect inferences. In survival analysis, the distribution of frailty is ...

It is introduced the proportional hazards frailty model to allow a discrete distribution for the frailty variable. Frailty zero can be interpreted as being immune or cured. It is defined a class of survival models induced ...

The present work's main objective is to study the significance of zeros in an observable and latent data. In observable data set that occur excess of zeros, its common to have sobredispersion. In this sense, the models ...

Services companies like telephony, health plans, internet and others, have redirect their marketing strategies in the customers retention. By maintaining a business relationship with their consumers, companies guarantee ...

Population aging is a known fact and accompanied by international policies, with a view to promoting health conditions in order to generate satisfactory experiences, with preservation of autonomy and quality of life for ...