In this article we combine ideas from spatial statistics with lifetime data analysis techniques to investigate possible spatial variation in survival of adult acute myeloid leukemia patients in northwest England. Exploratory analysis suggests both clinically and statistically signiŽ cant variation in survival rates across the region. A multivariate gamma frailty model incorporating spatial depe...

In recent years substantial research has been devoted to developing failure-time methodology which accounts for possible dependency between observations. An example is the univariate frailty model (Vaupel, Manton & Stallard, 1979), which incorporates an exchangeable dependence structure by the inclusion of cluster-specific random effects. In some studies it may be reasonable to expect more than...

BACKGROUND Frailty is not universal among older people but increases the risk of dependence. AIM To assess frailty among older people and its relationship with biological, psychological and social factors. MATERIAL AND METHODS Seven hundred fifty four older people aged 73 ± 6 years (61% females), attending a public primary care were assessed. Frailty was defined according to Fried criteria ...

This paper proposes a general framework to compare the strength of the dependence in survival models, as time changes, i. e. given remaining lifetimes X , to compare the dependence of X given X > t, and X given X > s, where s > t. More precisely, analytical results will be obtained in the case the survival copula of X is either Archimedean or a distorted copula. The case of a frailty based mode...

The Gompertz distribution has many applications, particularly in medical and actuarial studies. However, there has been little recent work on the Gompertz in comparison with its early investigation. The problem of analyzing and estimating parameters of bivariate Gompertz distribution with shared frailty is of interest and the focus of this paper. We propose maximum likelihood estimation procedu...

The observation of time to tumour progression (TTP) or progression-free survival (PFS) may be terminated by a terminal event. In this context, deaths may be due to tumour progression, and the time to the major failure event (death) may be correlated with the TTP. The usual assumption of independence between the TTP process and death, required by many commonly used statistical methods, can be vi...

Gap time hazard estimation is of particular interest in recurrent event data. This article proposes a fully nonparametric approach for estimating the gap time hazard. Smoothing spline analysis of variance (ANOVA) decompositions are used to model the log gap time hazard as a joint function of gap time and covariates, and general frailty is introduced to account for between-subject heterogeneity ...

This paper proposes nonparametric and semi-nonparametric estimation of hazard models with various types of dependence between observations. The methods are designed to examine the impact that di¤erent macroeconomic and …nancial conditions have on hazard rates. First, dependence between time-varying covariate processes across observations is examined. Among other possibilities, covariate process...

BACKGROUND Injuries are often recurrent, with subsequent injuries influenced by previous occurrences and hence correlation between events needs to be taken into account when analysing such data. OBJECTIVE This paper compares five different survival models (Cox proportional hazards (CoxPH) model and the following generalisations to recurrent event data: Andersen-Gill (A-G), frailty, Wei-Lin-We...