Manuel Mayrdorfer


2021

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Assertion Detection in Clinical Notes: Medical Language Models to the Rescue?
Betty van Aken | Ivana Trajanovska | Amy Siu | Manuel Mayrdorfer | Klemens Budde | Alexander Loeser
Proceedings of the Second Workshop on Natural Language Processing for Medical Conversations

In order to provide high-quality care, health professionals must efficiently identify the presence, possibility, or absence of symptoms, treatments and other relevant entities in free-text clinical notes. Such is the task of assertion detection - to identify the assertion class (present, possible, absent) of an entity based on textual cues in unstructured text. We evaluate state-of-the-art medical language models on the task and show that they outperform the baselines in all three classes. As transferability is especially important in the medical domain we further study how the best performing model behaves on unseen data from two other medical datasets. For this purpose we introduce a newly annotated set of 5,000 assertions for the publicly available MIMIC-III dataset. We conclude with an error analysis that reveals situations in which the models still go wrong and points towards future research directions.

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Clinical Outcome Prediction from Admission Notes using Self-Supervised Knowledge Integration
Betty van Aken | Jens-Michalis Papaioannou | Manuel Mayrdorfer | Klemens Budde | Felix Gers | Alexander Loeser
Proceedings of the 16th Conference of the European Chapter of the Association for Computational Linguistics: Main Volume

Outcome prediction from clinical text can prevent doctors from overlooking possible risks and help hospitals to plan capacities. We simulate patients at admission time, when decision support can be especially valuable, and contribute a novel *admission to discharge* task with four common outcome prediction targets: Diagnoses at discharge, procedures performed, in-hospital mortality and length-of-stay prediction. The ideal system should infer outcomes based on symptoms, pre-conditions and risk factors of a patient. We evaluate the effectiveness of language models to handle this scenario and propose *clinical outcome pre-training* to integrate knowledge about patient outcomes from multiple public sources. We further present a simple method to incorporate ICD code hierarchy into the models. We show that our approach improves performance on the outcome tasks against several baselines. A detailed analysis reveals further strengths of the model, including transferability, but also weaknesses such as handling of vital values and inconsistencies in the underlying data.