surv_cox: Survival Effect Estimation with Cox Censoring Scores

In PSsurvival: Propensity Score Methods for Survival Analysis

Survival Effect Estimation with Cox Censoring Scores

Description

Implements Estimator I (AJE 2022, Eq. 2) combining propensity score weighting and inverse probability of censoring weighting to estimate counterfactual survival functions and treatment effects. Variance estimation uses bootstrap only. Estimate Counterfactual Survival Functions Using Cox Censoring Scores

Usage

surv_cox(
  data,
  time_var,
  event_var,
  treatment_var,
  eval_times = NULL,
  weight_result,
  censoring_formula,
  censoring_control = list(),
  ties = "efron"
)

Arguments

data	Data frame.
time_var	Name of time variable.
event_var	Name of event indicator (1 = event, 0 = censored).
treatment_var	Name of treatment variable.
eval_times	Numeric vector of time points. If NULL, uses all unique event times.
weight_result	Output from estimate_weights().
censoring_formula	Formula for censoring score model.
censoring_control	Control parameters for coxph(). Default list().
ties	Tie handling method for Cox model. Default "efron".

Details

Estimates counterfactual survival function for each treatment group j:

S^{(j)}_w(t) = 1 - \frac{\sum_i w_i I(A_i=j) \delta_i I(T_i \leq t) / K_c^{(j)}(T_i, X_i)}{\sum_i w_i I(A_i=j)}

Censoring scores are estimated using Cox proportional hazards models fit separately within each treatment group. Variance estimation for Cox-based survival functions is performed using bootstrap only (no analytical variance available).

Value

List containing:

survival_matrix	Matrix [time x J] of survival function estimates S^(j)(t).
eval_times	Time points evaluated.
treatment_levels	Treatment level values.
n_levels	Number of treatment levels.
weights_by_group	List of weight vectors by treatment group.
censoring_scores_by_group	List of censoring score vectors by group.
method, estimand	Weighting method and target estimand.
censoring_result, ps_result, weight_result	Input objects.
Z_matrix	Binary indicator matrix [n x J] for treatment groups.
time_vec, event_vec	Original time and event vectors.

PSsurvival documentation built on Dec. 9, 2025, 9:07 a.m.