BACKGROUND Gastric cancer is the one of the most prevalent reason of cancer-related death in the world. Survival of patients after surgery involves identifying risk factors. There are various models to detect the effect of risk factors on patients' survival. The present study aims at evaluating these models. METHODS Data from 330 gastric cancer patients diagnosed at the Iran cancer institute ...

Introduction: Colorectal cancer (CRC) is a commonly fatal cancer that ranks as third worldwide and third and the fifth in Iranian women and men, respectively. There are several methods for analyzing time to event data. Additive hazards regression models take priority over the popular Cox proportional hazards model if the absolute hazard (risk) change instead of hazard ratio is of primary concer...

Cox proportional hazards model is a commonly used model in providing hazard ratio to compare survival times of two population groups. The exponentiated linear regression part of the model describes the effects of explanatory variables on hazard ratio. PROC PHREG is a SAS procedure that implements the Cox model and provides the hazard ratio estimate. The estimate is interpreted as the percent ch...

BACKGROUND Randomized Controlled Trials almost invariably utilize the hazard ratio calculated with a Cox proportional hazard model as a treatment efficacy measure. Despite the widespread adoption of HRs, these provide a limited understanding of the treatment effect and may even provide a biased estimate when the assumption of proportional hazards in the Cox model is not verified by the trial da...

Survival analysis is a statistical method used to analyze data with time until the occurrence of certain event which commonly referred as "failure". One objectives survival determine effect predictor variables on time. The purpose this study was regression model and hazard ratio each factor that thought affect cervical cancer patients. results showed factors influence patients in their are stag...

The primary objective of this work was to investigate and compare the use of the Cox proportional hazards model and Aalen’s additive model in analysing survival data. Survival data from a study of 52 patients with advanced breast cancer was investigated using the Cox proportional hazards model. The model was optimized by examining different aspects by use of appropriate residual plots. Covariat...