background: cox proportional hazard (cph) model is the most widely used model for survival analysis. when there are unobserved/unmeasured individuals factor, then the results of the cox proportional hazard model may not be reliable. the purpose of this study was to compare the results of cph and frailty models in breast cancer (bc) patients. methods: a historical cohort study was carried out us...

For multivariate failure time data, we propose a new class of shared gamma frailty models by imposing the Box-Cox transformation on the hazard function, and the product of the baseline hazard and the frailty. This novel class of models allows for a very broad range of shapes and relationships between the hazard and baseline hazard functions. It includes the well-known Cox gamma frailty model an...

tires represent a critical spare part in mines. there is a shortage of medium and large tires. in addition, with increased mining activities and the creation of new mines, the demand for tires has increased significantly. thus, it is particularly important for mining engineers to identify tire characteristics and correctly manage the spare part inventory. spare parts management is critical from...

Semiparametric hazard function regression models are among the well studied risk models in survival analysis. The Cox proportional hazards model has been a popular choice in modelling data from epidemiological settings. The Cox-Aalen model is one of the tools for handling the problem of non-proportional effects in the Cox model. We show an application on Piedmont cancer registry data. We initia...

Methods Using data from two clinical trials in advanced stage pancreatic cancer, a prognostic model was developed using Royston-Parmar (R-P) flexible parametric survival models. R-P models use restricted cubic splines to model the baseline hazard function for time-to-event data and thereby allows absolute risk to be predicted for individuals. This contrasts the Cox regression approach which doe...

background: including multivariate survival data can be pointed competing risks data. there are various methods to analyze such data such as semi-parametric methods of cause-specific hazard function, and cumulative incidence function. the aim of this study was to deploy competing risks model to analyze the determinants of patients with liver cirrhosis. materials and methods: during the one-year...