Questions tagged [accelerated-failure-time]
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Constructing nomogram from approximate model in Regression Modelling Strategies
In section 19.5 in Regression Modelling Strategies by Frank Harrell we make an approximate model using linear regression with ols. Since this is an ols object we have to calculate survival quantities ...
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Interpreting AFT or Cox PH model in terms of median
An AFT model has been fit, with a binary sex variable. The coefficient estimate of female was 0.416 (reference level is Male). The interpretation of the coefficient is provided as below.:
"This ...
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What is the distribution of error term in Gompertz AFT model?
Given the AFT model $\ln(T)=\beta+\sigma\times W$, the distribution of $T$ depends on the random term $W$. If $T$ follows a Gompertz distribution with the shape and rate, how can I derive the value of ...
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Interpreting AFT Model Coefficients: Mean vs. Median Survival Time in Log-Normal Distribution
When interpreting the coefficients of an Accelerated Failure Time (AFT) model that assumes a log-normal distribution, should we focus on the impact of coefficients on the mean survival time or the ...
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Best way to write the likelihood of a model?
Suppose we have the classic AFT (Accelerated Failure Time) model:
$$\log T = -X'\beta + \epsilon$$
I have seen the Likelihood corresponding to this model written in different ways.
For example, I have ...
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How to write a Gompertz model as an accelerated failure time model?
Accelerated failure time models are usually defined as a model for $X>0$ with (constants) covariates $Z\in \mathbb{R}^p$ such that
\begin{equation}
\log(X) = \mu + \beta^*Z + \sigma W,
\end{...
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The AFT and PH model
According to the following - https://dylanspicker.com/courses/STAT437/content/041%20+%20044.%20Lecture%20Notes.pdf
the PH and AFT models are equivalent for Weibull distribution.
Does this implies the ...
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Counting process equality for linear rank test under AFT model
I am currently reading through the paper:
Estimating Regression Parameters Using Linear Rank Tests for Censored Data - A.A. Tsiatis, Annals of Statistics 18(1): 354-372, 1990.
https://projecteuclid....
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R package for Accelerated failure time Models with arbitrary censoring and left truncation
This is a simple exploratory R question i hope somebody can help me with. I am trying to model accelerated failure time models on data that is arbitrarily censored (right, left, or interval censored) ...
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Test assumptions Log-Logistic AFT Model
I'm considering adopting a Log-logistic Accelerated Failure Time (AFT) model for my analysis. Initially, I contemplated using the Cox Proportional Hazards (PH) model; however, the PH assumption was ...
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How to speed up aftreg estimation?
I am performing an Accelerated Failure Time (AFT) regression data on a panel setting (multiple records per observation with time-dependent variables) using the eha ...
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Choice between Proportional Hazard and Accelerated Failure Time survival models
How can I determine whether to use proportional hazard (PH) or accelerate failure time (AFT) survival models in order to analyze my data?
Are there any established guidelines or common practices that ...
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Options on modelling a hazard function with a turning point
I have some survival data and need to fit survival models to it and extrapolate. I plotted the log cumulative hazard and empirical hazard plot (using muhaz). There appears to be a change in the hazard ...
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How do I choose correct model (AFT or PH) & distribution when Cox proportional hazards is not appropriate?
I have been tasked with evaluating hospital length of stay (LOS) in two groups of patients using the Cox proportional hazards model. One group of patients received a medication, the other did not. ...
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How to predict survival curves with step changes over time
I'm trying to predict the survival curves for customers, knowing that for some rare customers after a certain time the survival probability has a jump. Those jumps are due to endings of minimum ...
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