Object returned by fmsm representing a flexible parametric multi-state model. This must be Markov, rather than semi-Markov, and no check is performed for this. Note that all "competing risks" style models, with just one source state and multiple destination states, are Markov, so those are fine here.

Maximum time to compute parametric estimates to.

Data frame defining the subgroups to consider. This must have a column for each covariate in the model. If omitted, then all potential subgroups defined by combinations of factor covariates are included. Continuous covariates are not supported.