A Simulation Study on Cox Regression with Weighted Estimations

Cox regression model has an important and glaring place in survival analysis. The key assumption is proportional hazards and violation of this assumption can invalidate outcomes of a study. Our approach will be to use Cox regression model with weighted estimation for a survival data set that includes both proportional and nonproportional hazards. We carried out a simulation study, considering different censoring rates, sample sizes, and tied observations. Simulation results are interpreted and discussed with the results obtained by traditional Cox regression model. Cox regression model with N-Prentice weighting function serves as a better model under all simulation scenarios