Clustering Aware Classification for Risk Prediction and Subtyping in Clinical Data

TL;DR

This paper introduces a novel clustering-aware classification method, DeepCAC, that improves risk prediction and subtyping in heterogeneous clinical data by leveraging deep learning to find optimal clusters for classifier training.

Contribution

The paper proposes a generic, deep learning-based clustering aware classification algorithm, DeepCAC, that enhances classifier performance on heterogeneous data by optimizing cluster formation.

Findings

DeepCAC outperforms previous methods on synthetic datasets.

DeepCAC demonstrates superior accuracy on real benchmark datasets.

Theoretical analysis shows conditions where clustering improves classification.

Abstract

In data containing heterogeneous subpopulations, classification performance benefits from incorporating the knowledge of cluster structure in the classifier. Previous methods for such combined clustering and classification either 1) are classifier-specific and not generic, or 2) independently perform clustering and classifier training, which may not form clusters that can potentially benefit classifier performance. The question of how to perform clustering to improve the performance of classifiers trained on the clusters has received scant attention in previous literature, despite its importance in several real-world applications. In this paper, first, we theoretically analyze the generalization performance of classifiers trained on clustered data and find conditions under which clustering can potentially aid classification. This motivates the design of a simple k-means-based classification algorithm called Clustering Aware Classification (CAC) and its neural variant {DeepCAC}. DeepCAC effectively leverages deep representation learning to learn latent embeddings and finds clusters in a manner that make the clustered data suitable for training classifiers for each underlying subpopulation. Our experiments on synthetic and real benchmark datasets demonstrate the efficacy of DeepCAC over previous methods for combined clustering and classification.