DID-EC-IPW method — did_ec

Creates a method object for difference-in-differences inverse probability weighting (DID-EC-IPW) estimation with external control borrowing for the open-label extension phase (Zhou et al., 2024, Eq. 4).

Usage

did_ec_ipw(
  ps_formula,
  trt_formula = NULL,
  bootstrap = 500L,
  bootstrap_ci_type = NULL
)

Arguments

ps_formula: Formula string for the propensity score model predicting trial participation.
trt_formula: Formula string for the treatment assignment model, or NULL (default) for marginal probability.
bootstrap: Number of bootstrap replicates (required for DID methods). Defaults to 500.
bootstrap_ci_type: Bootstrap CI type. Defaults to "perc".

Value

An S4 object of class did_ec_ipw_method.

References

Zhou et al. (2024). Estimating treatment effect in randomized trial after control to treatment crossover using external controls. Journal of Biopharmaceutical Statistics. doi:10.1080/10543406.2024.2444222

Examples

did_ec_ipw(
  ps_formula = "S ~ x1 + x2 + x3 + x4 + x5",
  trt_formula = "A ~ x1 + x2 + x3 + x4 + x5",
  bootstrap = 500
)
#> An object of class "did_ec_ipw_method"
#> Slot "ps_formula":
#> [1] "S ~ x1 + x2 + x3 + x4 + x5"
#> 
#> Slot "trt_formula":
#> [1] "A ~ x1 + x2 + x3 + x4 + x5"
#> 
#> Slot "method_name":
#> [1] "DID-EC-IPW"
#> 
#> Slot "bootstrap":
#> [1] 500
#> 
#> Slot "bootstrap_ci_type":
#> [1] "perc"
#>