A list of tables required for health economic simulation modeling. This object is used to setup models by defining the treatment strategies, target population, and model structure.

`hesim_data(strategies, patients, states = NULL, transitions = NULL)`

- strategies
A table of treatment strategies. Must contain the column

`strategy_id`

denoting a unique strategy. Other columns are variables describing the characteristics of a treatment strategy.- patients
A table of patients. Must contain the column

`patient_id`

denoting a unique patient. The number of rows should be equal to the number of patients in the model. The table may also include columns for`grp_id`

for subgroups and`patient_wt`

specifying the weight to apply to each patient (within a subgroup). If`grp_id`

is`NULL`

, then it is assumed that there is only one subgroup. If`patient_wt`

is`NULL`

. then each patient is given the same weight. Weights cannot be used in individual-level models because each patient should be weighted equally; that is, weights can only be specified in cohort models. Weights within subgroups are normalized to sum to one. Other columns are variables describing the characteristics of a patient.- states
A table of health states. Must contain the column

`state_id`

, which denotes a unique health state. The number of rows should be equal to the number of health states in the model. Other columns can describe the characteristics of a health state.- transitions
A table of health state transitions. Must contain the column

`transition_id`

, which denotes a unique transition;`from`

, which denotes the starting health state; and`to`

which denotes the state that will be transitioned to.

Returns an object of class `hesim_data`

, which is a list of data tables for
health economic simulation modeling.

Each table must either be a `data.frame`

or `data.table`

. All ID variables
within each table must be numeric vectors of integers and should be of the form
1,2,...N where N is the number of unique values of the ID variable.

```
strategies <- data.frame(strategy_id = c(1, 2))
patients <- data.frame(patient_id = seq(1, 3), age = c(65, 50, 75),
gender = c("Female", "Female", "Male"))
states <- data.frame(state_id = seq(1, 3),
state_var = c(2, 1, 9))
hesim_dat <- hesim_data(strategies = strategies,
patients = patients,
states = states)
```