Treatment effect parameter covariance matrix

Extract the covariance matrix of the treatment effect parameters of a progression model for repeated measures.

Usage

# S3 method for class 'pmrm_fit'
vcov(object, ...)

Arguments

object

A fitted model object of class "pmrm_fit".

...

Not used.

Value

A matrix with covariance of each pair of theta parameters. Rows and columns are labeled (by just study arm for proportional models, arm and visit for non-proportional models.)

See also

Other estimates: VarCorr.pmrm_fit(), coef.pmrm_fit(), pmrm_marginals(), tidy.pmrm_fit()

Examples

  set.seed(0L)
  simulation <- pmrm_simulate_decline_proportional(
    visit_times = seq_len(5L) - 1,
    gamma = c(1, 2)
  )
  fit <- pmrm_model_decline_proportional(
    data = simulation,
    outcome = "y",
    time = "t",
    patient = "patient",
    visit = "visit",
    arm = "arm",
    covariates = ~ w_1 + w_2
  )
  vcov(fit)
#>             arm_2       arm_3
#> arm_2 0.002912489 0.001176870
#> arm_3 0.001176870 0.002767405