Ordering of series and parallel systems comprising heterogeneous generalized modified Weibull components

2018 ◽  
Vol 34 (6) ◽  
pp. 816-834 ◽  
Author(s):  
Narayanaswamy Balakrishnan ◽  
Phalguni Nanda ◽  
Suchandan Kayal
Keyword(s):  
Parallel Systems ◽  
Generalized Modified Weibull ◽  
Modified Weibull

Bayesian mixture cure rate frailty models with an application to gastric cancer data

2020 ◽  
pp. 096228022097469
Author(s):  
Ali Karamoozian ◽  
Mohammad Reza Baneshi ◽  
Abbas Bahrampour
Keyword(s):  
Gastric Cancer ◽  
Bayesian Inference ◽  
Weibull Distribution ◽  
Survival Data ◽  
Random Variable ◽  
Frailty Models ◽  
Accurate Estimation ◽  
Cure Rate ◽  
Generalized Modified Weibull ◽  
Modified Weibull

Mixture cure rate models are commonly used to analyze lifetime data with long-term survivors. On the other hand, frailty models also lead to accurate estimation of coefficients by controlling the heterogeneity in survival data. Gamma frailty models are the most common models of frailty. Usually, the gamma distribution is used in the frailty random variable models. However, for survival data which are suitable for populations with a cure rate, it may be better to use a discrete distribution for the frailty random variable than a continuous distribution. Therefore, we proposed two models in this study. In the first model, continuous gamma as the distribution is used, and in the second model, discrete hyper-Poisson distribution is applied for the frailty random variable. Also, Bayesian inference with Weibull distribution and generalized modified Weibull distribution as the baseline distribution were used in the two proposed models, respectively. In this study, we used data of patients with gastric cancer to show the application of these models in real data analysis. The parameters and regression coefficients were estimated using the Metropolis with Gibbs sampling algorithm, so that this algorithm is one of the crucial techniques in Markov chain Monte Carlo simulation. A simulation study was also used to evaluate the performance of the Bayesian estimates to confirm the proposed models. Based on the results of the Bayesian inference, it was found that the model with generalized modified Weibull and hyper-Poisson distributions is a suitable model in practical study and also this model fits better than the model with Weibull and Gamma distributions.

Sign in / Sign up

Export Citation Format

Share Document