These functions are designed to extract (or mimic) the cumulative coefficients usually used in additive hazards models (Aalen model) to depict (time-varying) covariate effects. For PAMMs, these are the differences between the cumulative hazard rates where all covariates except one have the identical values. For a numeric covariate of interest, this calculates \(\Lambda(t|x+1) - \Lambda(t|x)\). For non-numeric covariates the cumulative hazard of the reference level is subtracted from the cumulative hazards evaluated at all non reference levels. Standard errors are calculated using the delta method.

get_cumu_coef(model, data = NULL, terms, ...)

# S3 method for gam
get_cumu_coef(model, data, terms, ...)

# S3 method for aalen
get_cumu_coef(model, data = NULL, terms, ci = TRUE, ...)

# S3 method for cox.aalen
get_cumu_coef(model, data = NULL, terms, ci = TRUE, ...)

Arguments

model

Object from which to extract cumulative coefficients.

data

Additional data if necessary.

terms

A character vector of variables for which the cumulative coefficient should be calculated.

...

Further arguments passed to methods.

ci

Logical. Indicates if confidence intervals should be returned as well.