recensor_sim_rpsftm: Simulation Study to Evaluate Recensoring Rules in RPSFTM

In trtswitch: Treatment Switching

Simulation Study to Evaluate Recensoring Rules in RPSFTM

Description

Simulates datasets to evaluate the performance of various recensoring strategies under the Rank Preserving Structural Failure Time Model (RPSFTM) for handling treatment switching in survival analysis.

Usage

recensor_sim_rpsftm(
  nsim = NA_integer_,
  n = NA_integer_,
  shape = NA_real_,
  scale = NA_real_,
  gamma = NA_real_,
  tfmin = NA_real_,
  tfmax = NA_real_,
  psi = NA_real_,
  omega = NA_real_,
  pswitch = NA_real_,
  a = NA_real_,
  b = NA_real_,
  low_psi = -1,
  hi_psi = 1,
  treat_modifier = 1,
  recensor_type = 1L,
  admin_recensor_only = 1L,
  autoswitch = 1L,
  alpha = 0.05,
  ties = "efron",
  tol = 1e-06,
  boot = 1L,
  n_boot = 1000L,
  seed = NA_integer_
)

Arguments

nsim	Number of simulated datasets.
n	Number of subjects per simulation.
shape	Shape parameter of the Weibull distribution for time to death.
scale	Scale parameter of the Weibull distribution for time to death in the control group.
gamma	Rate parameter of the exponential distribution for random dropouts in the control group.
tfmin	Minimum planned follow-up time (in days).
tfmax	Maximum planned follow-up time (in days).
psi	Log time ratio of death time for control vs experimental treatment.
omega	Log time ratio of dropout time for control vs experimental treatment.
pswitch	Probability of treatment switching at disease progression.
a	Shape parameter 1 of the Beta distribution for time to disease progression as a fraction of time to death.
b	Shape parameter 2 of the Beta distribution for time to disease progression.
low_psi	Lower bound for the search interval of the causal parameter \psi.
hi_psi	Upper bound for the search interval of the causal parameter \psi.
treat_modifier	Sensitivity parameter modifying the constant treatment effect assumption.
recensor_type	Type of recensoring to apply: 0: No recensoring 1: Recensor all control-arm subjects 2: Recensor only switchers in the control arm 3: Recensor only control-arm switchers whose counterfactual survival exceeds the planned follow-up time
admin_recensor_only	Logical. If TRUE, recensoring is applied only to administrative censoring times. If FALSE, it is also applied to dropout times.
autoswitch	Logical. If TRUE, disables recensoring in arms without any treatment switching.
alpha	Significance level for confidence interval calculation (default is 0.05).
ties	Method for handling tied event times in the Cox model. Options are "efron" (default) or "breslow".
tol	Convergence tolerance for root-finding in estimation of \psi.
boot	Logical. If TRUE, bootstrap is used to estimate the confidence interval for the hazard ratio. If FALSE, the confidence interval is matched to the log-rank p-value.
n_boot	Number of bootstrap samples, used only if boot = TRUE.
seed	Optional. Random seed for reproducibility. If not provided, the global seed is used.

Value

A data frame summarizing the simulation results, including:

• recensor_type, admin_recensor_only: Settings used in the simulation.

• Event rates: p_event_1, p_dropout_1, p_admin_censor_1, p_event_0, p_dropout_0, p_admin_censor_0.

• Progression and switching: p_pd_0, p_swtrt_0, p_recensored_0.

• Causal parameter (\psi) estimates: psi, psi_est, psi_bias, psi_se, psi_mse.

• Log hazard ratio estimates: loghr, loghr_est, loghr_se, loghr_mse.

• Hazard ratio metrics: hr, hr_est (geometric mean), hr_pctbias (percent bias).

• Standard errors of log hazard ratio: loghr_se_cox, loghr_se_lr, loghr_se_boot.

• Coverage probabilities: hr_ci_cover_cox, hr_ci_cover_lr, hr_ci_cover_boot.

Author(s)

Kaifeng Lu, [e-mail]

Examples

result <- recensor_sim_rpsftm(
  nsim = 10, n = 400, shape = 1.5, scale = exp(6.3169),
  gamma = 0.001, tfmin = 407.5, tfmax = 407.5,
  psi = log(0.5) / 1.5, omega = log(1), pswitch = 0.7,
  a = 2, b = 4, low_psi = -5, hi_psi = 5,
  treat_modifier = 1, recensor_type = 1,
  admin_recensor_only = TRUE, autoswitch = TRUE,
  alpha = 0.05, tol = 1e-6, boot = TRUE,
  n_boot = 10, seed = 314159)

trtswitch documentation built on Nov. 5, 2025, 7:08 p.m.