Dependence Measures in Bivariate Gamma Frailty Models Bivariate duration data frequently arise in economics, biostatistics and other areas. In “bivariate frailty models”, dependence between the frailties (i.e., unobserved determinants) induces dependence between the durations. Using notions of quadrant dependence, we study restrictions that this imposes on the implied dependence of the duration...

Frailty is a health condition related to aging and dependence. A reduction or delay of frailty state can improve the quality of elderly life. However, providing a frailty assessment is difficult because many factors must be taken into account. Most of the time, measurement of these factors is performed in a non-centralized way, encouraging physician to make a wrong diagnosis or not as objective...

Survival Model is widely used in medical field and biostatistics. This model can be used to identify the risk factors of an event and can handle the situation when risk factors change with time. Timing of an event frequently depends on the location (spatial) called as spatial survival model. In the development, survival modeling also included random effects models (frailty) to overcome the hete...

Due to natural or artificial clustering, multivariate survival data often arise in biomedical studies, for example, a dental study involving multiple teeth from each subject. A certain proportion of subjects in the population who are not expected to experience the event of interest are considered to be "cured" or insusceptible. To model correlated or clustered failure time data incorporating a ...

BACKGROUND In developing countries about 3.5% of children aged 0-5 years are victims of severe acute malnutrition (SAM). Once the morbidity has developed the cure process takes variable period depending on various factors. Knowledge of time-to-cure from SAM will enable health care providers to plan resources and monitor the progress of cases with SAM. The current analysis presents modeling time...

background : malnutrition represents an important issue in older adults; unfortunately, there is lack of data concerning this topic in lebanon. this paper aims to provide a description of nutritional status and its correlates in older adults living in long stay institutions situated in beirut. methods : this cross-sectional study was conducted in three long stay institutions in beirut in 2012. ...

BACKGROUND In countries with high incomes, frailty indicators predict adverse outcomes in older people, despite a lack of consensus on definition or measurement. We tested the predictive validity of physical and multidimensional frailty phenotypes in settings in Latin America, India, and China. METHODS Population-based cohort studies were conducted in catchment area sites in Cuba, Dominican R...

1 Summary In this work we provide a simple estimation procedure for a general frailty model for analysis of prospective correlated failure times. Rigorous large-sample theory for the proposed estimators of both the regression coefficient vector and the dependence parameter is given, including consistent variance estimators. In a simulation study under the widely used gamma frailty model, our pr...

We present a hierarchical frailty model based on distributions derived from non-negative Lévy processes. The model may be applied to data with several levels of dependence, such as family data or other general clusters, and is an alternative to additive frailty models. We present several parametric examples of the model, and properties such as expected values, variance and covariance. The model...