# Create cost models

Source: `R/costmods.R`
`create_costmods.Rd`

Create a cost model for four cost categories: (i) treatment costs (i.e., drug acquisition and administration costs), (ii) inpatient medical costs, (iii) outpatient medical costs, and (iv) costs due to adverse events.

    create_costmods(n = 100, struct, patients, ae_probs,
      params_costs_tx = iviNSCLC::params_costs_tx,
      params_costs_op = iviNSCLC::params_costs_op,
      params_costs_inpt = iviNSCLC::params_costs_inpt,
      params_costs_ae = iviNSCLC::params_costs_ae)

## Arguments

n | The number of random observations of the parameters to draw.
struct | A `model_structure` object.
patients | A data table returned from `create_patients`.
ae_probs | An "ae_probs" object as returned by `ae_probs`.
params_costs_tx | Parameter estimates for treatment costs (i.e., acquisition and administration costs) in the same format as `params_costs_tx`.
params_costs_op | Parameter estimates for outpatient medical costs in the same format as `params_costs_op`.
params_costs_inpt | Parameter estimates for inpatient medical costs in the same format as `params_costs_inpt`.
params_costs_ae | Parameter estimates for adverse event costs in the same format as `params_costs_ae`.

## Value

A list of objects of class "StateVals" from the hesim package.

## Examples

    # Treatment sequences
    txseq1 <- txseq(first = "erlotinib",
                    second = c("osimertinib", "PBDC"),
                    second_plus = c("PBDC + bevacizumab", "PBDC + bevacizumab"))
    txseq2 <- txseq(first = "gefitinib",
                    second = c("osimertinib", "PBDC"),
                    second_plus = c("PBDC + bevacizumab", "PBDC + bevacizumab"))
    txseqs <- txseq_list(seq1 = txseq1, seq2 = txseq2)

    # Patient population
    pats <- create_patients(n = 2)

    # Model structure
    struct <- model_structure(txseqs, dist = "weibull")

    ## Cost models
    n_samples <- 2
    ae_probs <- ae_probs(n = n_samples, struct = struct)
    costmods <- create_costmods(n = 2, struct = struct, patients = pats,
                                ae_probs = ae_probs)