Evaluating the Effectiveness of advanced large language models in medical Knowledge: A Comparative study using Japanese national medical examination

GPT-4o achieved an overall accuracy rate close to 90%, with 95.0% on easy questions, significantly outperforming the other LLMs. This indicates GPT-4o's potential as a knowledge source for easy questions. Image-based questions and question difficulty significantly impact LLM accuracy. "Gastroenterology and Hepatology" is the specialty with the lowest performance. The LLMs' performance across medical specialties correlates positively with the number of related publications.