Copula-based semiparametric nonnormal transformed linear model for survival data with dependent censoring

TL;DR

This paper introduces a flexible semiparametric copula-based model for survival data with dependent censoring, addressing violations of the independent censoring assumption common in survival analysis.

Contribution

It proposes a joint transformed linear model with unspecified transformation functions and copula-based bivariate nonnormal distribution, allowing for dependent censoring and covariate effects.

Findings

Model is identifiable and statistically consistent.

Simulation studies show good performance under various scenarios.

Real data example demonstrates practical applicability.

Abstract

Although the independent censoring assumption is commonly used in survival analysis, it can be violated when the censoring time is related to the survival time, which often happens in many practical applications. To address this issue, we propose a flexible semiparametric method for dependent censored data. Our approach involves fitting the survival time and the censoring time with a joint transformed linear model, where the transformed function is unspecified. This allows for a very general class of models that can account for possible covariate effects, while also accommodating administrative censoring. We assume that the transformed variables have a bivariate nonnormal distribution based on parametric copulas and parametric marginals, which further enhances the flexibility of our method. We demonstrate the identifiability of the proposed model and establish the consistency and asymptotic normality of the model parameters under appropriate regularity conditions and assumptions. Furthermore, we evaluate the performance of our method through extensive simulation studies, and provide a real data example for illustration.