Understanding Transformer-Based Classifications of Medical Text Using a Large Language Model for the Attribution of Feature Importance: Proof-of-Concept Algorithm Development and Validation Study

Fangwen Zhou   ¹ , MSc ;   Ashirbani Saha   ² , PhD ;   Muhammad Afzal   ³ , PhD ;   Rick Parrish   ¹ ;   R Brian Haynes   ¹ , MD, PhD ;   Alfonso Iorio   ^{1, 4} , MD, PhD ;   Cynthia Lokker   ¹ , PhD

¹ Health Information Research Unit, Department of Health Research Methods, Evidence, and Impact, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada

² Department of Oncology, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada

³ Department of Computer Science, Birmingham City University, Birmingham, United Kingdom

⁴ Department of Medicine, Faculty of Health Sciences, McMaster University, Hamilton, ON, Canada