Recent advances in large language models have led to renewed interest in natural language processing in healthcare using the free text of clinical notes. One distinguishing characteristic of clinical notes is their long time span over multiple long documents. The unique structure of clinical notes creates a new design choice: when the context length for a language model predictor is limited, which part of clinical notes should we choose as the input? Existing studies either choose the inputs with domain knowledge or simply truncate them. We propose a framework to analyze the sections with high predictive power. Using MIMIC-III, we show that: 1) predictive power distribution is different between nursing notes and discharge notes and 2) combining different types of notes could improve performance when the context length is large. Our findings suggest that a carefully selected sampling function could enable more efficient information extraction from clinical notes.

本论文通过研究MIMIC-III数据集中的病历笔记，提出了一个基于自然语言处理模型的框架，通过挑选预测能力高的笔记部分来实现有效的信息提取，并在不同类型的笔记结合时提高了模型的性能。

利用有限的上下文长度发挥最大的预测能力：预测能力因临床记录类型和记录部分而异