Analyzing the health status of patients based on Electronic Health Records
(EHR) is a fundamental research problem in medical informatics. The presence of
extensive missing values in EHR makes it challenging for deep neural networks
to directly model the patient's health status based on EHR. Existing deep
learning training protocols require the use of statistical information or
imputation models to reconstruct missing values; however, the protocols inject
non-realistic data into downstream EHR analysis models, significantly limiting
model performance. This paper introduces Learnable Prompt as Pseudo Imputation
(PAI) as a new training protocol. PAI no longer introduces any imputed data but
constructs a learnable prompt to model the implicit preferences of the
downstream model for missing values, resulting in a significant performance
improvement for all EHR analysis models. Additionally, our experiments show
that PAI exhibits higher robustness in situations of data insufficiency and
high missing rates. More importantly, in a real-world application involving
cross-institutional data with zero-shot evaluation, PAI demonstrates stronger
model generalization capabilities for non-overlapping features.

基于电子健康记录（EHR）分析患者的健康状况是医学信息学中的一个基础研究问题。现有的深度学习训练协议需要使用统计信息或填补模型来重构缺失值，但是这限制了模型性能。本文引入了 Learnable Prompt as Pseudo Imputation（PAI）作为一种新的训练协议，通过构建可学习的提示来模拟下游模型对缺失值的隐含偏好，从而显著提高所有 EHR 分析模型的性能。此外，实验结果表明，在数据不足和高缺失率的情况下，PAI 表现出更高的鲁棒性。更重要的是，在涉及零射评估的跨机构数据的真实应用中，PAI 展现了更强的模型泛化能力，特别是对非重叠特征。