Fits an Accelerated Failure Time (AFT) regression model using the
Exponentiated Danish (ED) kernel, that is the Beta-Danish distribution with a = 1.
Usage
fit_bd_aft(formula, data, n_starts = 10, method = "BFGS")
Arguments
- formula
A survival formula (e.g., `Surv(time, status) ~ age + treatment`).
- data
A data frame containing the variables.
- n_starts
Integer; number of random starts for optimization.
- method
Optimization method passed to `maxLik`.
Value
An object of class `bd_aft`.
Details
To ensure identifiability, the shape parameter `a` is fixed to 1. The scale
parameter `k` is linked to covariates via `k_i = exp(X_i
Positive coefficients in `delta` indicate a larger `k`, which corresponds
to shorter survival times (accelerated failure).