Multimodal Prescriptive Deep Learning
Dimitris Bertsimas, Lisa Everest, Vasiliki Stoumpou
TL;DR
This work introduces Prescriptive Neural Networks (PNNs), a multimodal deep learning framework that integrates optimization with neural networks to output outcome-optimizing prescriptions from both structured and unstructured data. The method builds end-to-end embeddings, employs doubly robust counterfactual estimation, and uses a softmax-based policy learner to assign treatments, with interpretability recovered via Mirrored Optimal Classification Trees. Empirically, PNNs achieve significant outcome improvements on multimodal medical datasets (e.g., TAVR and liver trauma) and competitive results on unimodal tabular datasets, while maintaining stability and offering interpretable surrogates. The framework provides a flexible, scalable approach to data-driven prescription with realistic, robust prescriptions suitable for real-world deployment across diverse domains.
Abstract
We introduce a multimodal deep learning framework, Prescriptive Neural Networks (PNNs), that combines ideas from optimization and machine learning, and is, to the best of our knowledge, the first prescriptive method to handle multimodal data. The PNN is a feedforward neural network trained on embeddings to output an outcome-optimizing prescription. In two real-world multimodal datasets, we demonstrate that PNNs prescribe treatments that are able to significantly improve estimated outcomes in transcatheter aortic valve replacement (TAVR) procedures by reducing estimated postoperative complication rates by 32% and in liver trauma injuries by reducing estimated mortality rates by over 40%. In four real-world, unimodal tabular datasets, we demonstrate that PNNs outperform or perform comparably to other well-known, state-of-the-art prescriptive models; importantly, on tabular datasets, we also recover interpretability through knowledge distillation, fitting interpretable Optimal Classification Tree models onto the PNN prescriptions as classification targets, which is critical for many real-world applications. Finally, we demonstrate that our multimodal PNN models achieve stability across randomized data splits comparable to other prescriptive methods and produce realistic prescriptions across the different datasets.
