The Concordance Index decomposition: A measure for a deeper understanding of survival prediction models
2024 (English)In: Artificial Intelligence in Medicine, ISSN 0933-3657, E-ISSN 1873-2860, Vol. 148, article id 102781Article in journal (Refereed) Published
Abstract [en]
The Concordance Index (C-index) is a commonly used metric in Survival Analysis for evaluating the performance of a prediction model. In this paper, we propose a decomposition of the C-index into a weighted harmonic mean of two quantities: one for ranking observed events versus other observed events, and the other for ranking observed events versus censored cases. This decomposition enables a finer-grained analysis of the relative strengths and weaknesses between different survival prediction methods. The usefulness of this decomposition is demonstrated through benchmark comparisons against classical models and state-of-the-art methods, together with the new variational generative neural-network-based method (SurVED) proposed in this paper. The performance of the models is assessed using four publicly available datasets with varying levels of censoring. Using the C-index decomposition and synthetic censoring, the analysis shows that deep learning models utilize the observed events more effectively than other models. This allows them to keep a stable C-index in different censoring levels. In contrast to such deep learning methods, classical machine learning models deteriorate when the censoring level decreases due to their inability to improve on ranking the events versus other events.
Place, publisher, year, edition, pages
Elsevier B.V. , 2024. Vol. 148, article id 102781
Keywords [en]
Concordance Index, Evaluation metric, Survival analysis, Variational encoder–decoder, Machine Learning, Neural Networks, Computer, Bioinformatics, Forecasting, Learning systems, Signal encoding, Encoder-decoder, Evaluation metrics, Fine-grained analysis, Performance, Prediction modelling, Survival prediction, Weighted harmonic means, artificial neural network, Deep learning
National Category
Mathematics
Identifiers
URN: urn:nbn:se:ri:diva-71927DOI: 10.1016/j.artmed.2024.102781Scopus ID: 2-s2.0-85184733529OAI: oai:DiVA.org:ri-71927DiVA, id: diva2:1841123
Note
This research was performed under the CAISR+ project funded by the Swedish Knowledge Foundation
2024-02-272024-02-272024-02-27Bibliographically approved