DDxGym: Online Transformer Policies in a Knowledge Graph Based Natural Language Environment

Benjamin Winter, Alexei Gustavo Figueroa Rosero, Alexander Loeser, Felix Alexander Gers, Nancy Katerina Figueroa Rosero, Ralf Krestel


Abstract
Differential diagnosis (DDx) is vital for physicians and challenging due to the existence of numerous diseases and their complex symptoms. Model training for this task is generally hindered by limited data access due to privacy concerns. To address this, we present DDxGym, a specialized OpenAI Gym environment for clinical differential diagnosis. DDxGym formulates DDx as a natural-language-based reinforcement learning (RL) problem, where agents emulate medical professionals, selecting examinations and treatments for patients with randomly sampled diseases. This RL environment utilizes data labeled from online resources, evaluated by medical professionals for accuracy. Transformers, while effective for encoding text in DDxGym, are unstable in online RL. For that reason we propose a novel training method using an auxiliary masked language modeling objective for policy optimization, resulting in model stabilization and significant performance improvement over strong baselines. Following this approach, our agent effectively navigates large action spaces and identifies universally applicable actions. All data, environment details, and implementation, including experiment reproduction code, are made publicly available.
Anthology ID:
2024.lrec-main.396
Volume:
Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024)
Month:
May
Year:
2024
Address:
Torino, Italia
Editors:
Nicoletta Calzolari, Min-Yen Kan, Veronique Hoste, Alessandro Lenci, Sakriani Sakti, Nianwen Xue
Venues:
LREC | COLING
SIG:
Publisher:
ELRA and ICCL
Note:
Pages:
4438–4448
Language:
URL:
https://aclanthology.org/2024.lrec-main.396
DOI:
Bibkey:
Cite (ACL):
Benjamin Winter, Alexei Gustavo Figueroa Rosero, Alexander Loeser, Felix Alexander Gers, Nancy Katerina Figueroa Rosero, and Ralf Krestel. 2024. DDxGym: Online Transformer Policies in a Knowledge Graph Based Natural Language Environment. In Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024), pages 4438–4448, Torino, Italia. ELRA and ICCL.
Cite (Informal):
DDxGym: Online Transformer Policies in a Knowledge Graph Based Natural Language Environment (Winter et al., LREC-COLING 2024)
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PDF:
https://aclanthology.org/2024.lrec-main.396.pdf