Explainable Survival Analysis of Censored Clinical Data Using a Neural Network Approach

Survival analysis is a statistical approach widely employed to model the time of an event, such as a patient's death. Classical approaches include the Kaplan-Meier estimator and Cox proportional hazards regression, which assume a linear relationship between the model's covariates. However, the linearity assumption might pose challenges with high-dimensional data, thus stimulating interest in performing survival analysis using neural network models. In the present work, we implemented a deep Cox neural network (Cox-net) to predict the time of a cardiac event using patient data collected from the Myocardial Iron Overload in Thalassemia (MIOT) project. Cox-net achieved a concordance index (c-index) of 0.812 +/- 0.036, outperforming the classical Cox regression (0.790 +/- 0.040), and it demonstrated resilience to varying levels of censored patients. A permutation feature importance analysis identified fibrosis and sex as the most significant predictors, aligning with clinical knowledge. Cox-net was able to represent the nonlinear relationships between covariates and maintain reliable survival curve predictions in datasets with a large number of censored patients, making it a promising tool for determining the appropriate clinical pathway for thalassemic patients.