Diagnostic Inferencing via Improving Clinical Concept Extraction with Deep Reinforcement Learning: A Preliminary Study
; Proceedings of the 2nd Machine Learning for Healthcare Conference, PMLR 68:271-285, 2017.
Clinical diagnostic inferencing is a complex task, which often requires significant medical research and investigation based on an underlying clinical scenario. This paper proposes a novel approach by formulating the task as a reinforcement learning problem such that the system can infer the most probable diagnoses by optimizing clinical concept extraction from a free text case narrative via leveraging relevant external evidence. Such a formulation is deemed to be suitable due to the inherent complexity of the task and unavailability of sufficient annotated data. During training, the agent tries to learn the optimal policy through iterative search and consolidation of the most relevant clinical concepts that best describe a correct diagnosis. A deep Q-network architecture is trained to optimize a reward function that measures the accuracy of the candidate diagnoses and clinical concepts. Our preliminary experiments on the TREC CDS dataset demonstrate the effectiveness of our system over non-reinforcement learning-based strong baselines.