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, ...)
Object from which to extract cumulative coefficients.
Additional data if necessary.
A character vector of variables for which the cumulative coefficient should be calculated.
Further arguments passed to methods.
Logical. Indicates if confidence intervals should be returned as well.