Bayesian Integration of Nonlinear Incomplete Clinical Data
Lucía González-Zamorano, Nuria Balbás-Esteban, Vanessa Gómez-Verdejo, Albert Belenguer-Llorens, Carlos Sevilla-Salcedo
TL;DR
BIONIC tackles the challenge of integrating heterogeneous, high-dimensional clinical data with view-level missingness by learning a Bayesian dual-latent model that combines a generative space for missing data with a discriminative space for prediction. It uses pretrained, fixed embeddings as multimodal views and imposes sparsity through ARD priors to automatically prune irrelevant factors, while a joint inference scheme handles missing views and labels in a semi-supervised setting. The work contributes a principled treatment of missingness across variables, views, and labels, an intrinsic interpretability pipeline linking latent factors to inputs, and empirical validation across three diverse clinical datasets showing robust discriminative performance and improved calibration under incomplete data. The approach offers practical advantages for clinical decision support by enabling principled imputation, uncertainty quantification, and population-level insights into modality relevance, with potential extensions to temporal data and patient-specific explanations.
Abstract
Multimodal clinical data are characterized by high dimensionality, heterogeneous representations, and structured missingness, posing significant challenges for predictive modeling, data integration, and interpretability. We propose BIONIC (Bayesian Integration of Nonlinear Incomplete Clinical data), a unified probabilistic framework that integrates heterogeneous multimodal data under missingness through a joint generative-discriminative latent architecture. BIONIC uses pretrained embeddings for complex modalities such as medical images and clinical text, while incorporating structured clinical variables directly within a Bayesian multimodal formulation. The proposed framework enables robust learning in partially observed and semi-supervised settings by explicitly modeling modality-level and variable-level missingness, as well as missing labels. We evaluate BIONIC on three multimodal clinical and biomedical datasets, demonstrating strong and consistent discriminative performance compared to representative multimodal baselines, particularly under incomplete data scenarios. Beyond predictive accuracy, BIONIC provides intrinsic interpretability through its latent structure, enabling population-level analysis of modality relevance and supporting clinically meaningful insight.
