On bootstrap accuracy with censored data

In survival analysis with censored data, we consider three closely related survival function estimators: the Kaplan-Meier, Nelson and moment estimators. We derive the Edgeworth expansions for these three estimators with Studentization. Edgeworth expansions for the corresponding bootstrap statistics are also given. It is found that the bootstrap approximation is better than the normal approximation for the Studentized Kaplan-Meier and Nelson estimators, but not so for the Studentized moment estimator. With these results, we construct bootstrap-based confidence intervals with better coverage probabilities. We also include some simulations which show strong agreement with our theoretical findings.