On correlation rank screening for ultra-high dimensional competing risks data

Volume under the ROC surface for high-dimensional independent screening with ordinal competing risk outcomes

We propose a screening method for high-dimensional data with ordinal competing risk outcomes, which is time-dependent and model-free. Existing methods are designed for cause-specific variable screening and fail to evaluate how a biomarker is associated with multiple competing events simultaneously. The proposed method utilizes the Volume under the ROC surface (VUS), which measures the concordance between values of a biomarker and event status at certain time points and provides an overall evaluation of the discrimination capacity of a biomarker. We show that the VUS possesses the sure screening property, i.e., true important covariates can be retained with probability tending to one, and the size of the selected set can be bounded with high probability. The VUS appears to be a viable model-free screening metric as compared to some existing methods in simulation studies, and it is especially robust to data contamination. Through an analysis of breast-cancer gene-expression data, we illustrate the unique insights into the overall discriminatory capability provided by the VUS.

Fast Lasso-type safe screening for Fine-Gray competing risks model with ultrahigh dimensional covariates

The Fine-Gray proportional sub-distribution hazards (PSH) model is among the most popular regression model for competing risks time-to-event data. This article develops a fast safe feature elimination method, named PSH-SAFE, for fitting the penalized Fine-Gray PSH model with a Lasso (or adaptive Lasso) penalty. Our PSH-SAFE procedure is straightforward to implement, fast, and scales well to ultrahigh dimensional data. We also show that as a feature screening procedure, PSH-SAFE is safe in a sense that the eliminated features are guaranteed to be inactive features in the original Lasso (or adaptive Lasso) estimator for the penalized PSH model. We evaluate the performance of the PSH-SAFE procedure in terms of computational efficiency, screening efficiency and safety, run-time, and prediction accuracy on multiple simulated datasets and a real bladder cancer data. Our empirical results show that the PSH-SAFE procedure possesses desirable screening efficiency and safety properties and can offer substantially improved computational efficiency as well as similar or better prediction performance in comparison to their baseline competitors.