Variational bayesian inference for exponentiated weibullright-censored survnaldata
The Weibull, log-logistic and log-normal distributions represent the heavy-tailed distributions that are often used in modelling time-to-event data. While the loglogistic and log-normal distributions are mainly used for modelling unimodal hazard functions, the Weibull distribution is well-known f...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English English English |
| Published: |
2023
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| Subjects: | |
| Online Access: | http://eprints.uthm.edu.my/10976/1/24p%20JIBRIL%20ABUBAKAR.pdf http://eprints.uthm.edu.my/10976/2/JIBRIL%20ABUBAKAR%20COPYRIGHT%20DECLARATION.pdf http://eprints.uthm.edu.my/10976/3/JIBRIL%20ABUBAKAR%20WATERMARK.pdf |
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| Summary: | The Weibull, log-logistic and log-normal distributions represent the heavy-tailed
distributions that are often used in modelling time-to-event data. While the loglogistic
and log-normal distributions are mainly used for modelling unimodal hazard
functions, the Weibull distribution is well-known for modelling monotonic hazard
rates. The commonly applied estimation technique for this class of model is the
Maximum Likelihood Estimator (MLE). However, previous studies have established
the inadequacy of this technique for the exponentiated class of models, such as the
exponentiated-Weibull model. Thus, in this thesis, we revisited the parameter
estimation for the exponentiated-Weibull model class by introducing a new Bayesian
technique called Variational Bayes. We considered the case of accelerated failure time
(AFT) exponentiated-Weibull regression model with covariates. The AFT model was
developed using two comparative studies based on real-life Lung cancer and
simulated datasets. The AFT model parameters were estimated using the MLE,
Bayesian Metropolis-Hasting and Variational Bayes procedure. The data calibration
results showed that the exponentiated Weibull regression adequately describes the
time-toevent data. In addition, the Variational Bayesian procedure was found to be the
most efficient among the three estimation techniques considered |
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