A Discrete Joint Model for Entity and Relation Extraction from Clinical Notes.

Extracting clinical concepts and their relations from clinical narratives is one of the fundamental tasks in clinical natural language processing. Traditional solutions often separate this task into two subtasks with a pipeline architecture, which first recognize the named entities and then classify the relations between any possible entity pairs. The pipeline architecture, although widely used, has two limitations: 1) it suffers from error propagation from the recognition step to the classification step, 2) it cannot utilize the interactions between the two steps. To address the limitations, we investigated a discrete joint model based on structured perceptron and beam search to jointly perform named entity recognition (NER) and relation classification (RC) from clinical notes.