Abstract
The integration of large language models (LLMs) into clinical diagnostics presents significant challenges regarding their accuracy and reliability.This study aimed to evaluate the performance of DeepSeek R1, an open-source reasoning model, alongside two other LLMs, GPT-4.1 and Claude 3.5 Sonnet, across multiple-choice clinical cases.A dataset of complex medical cases representative of real-world clinical practice was selected.For efficiency, models were accessed via application programming interfaces (APIs) and assessed using standardized prompts and a predefined evaluation protocol.The models demonstrated an overall accuracy of 77.1%, with GPT-4 producing the fewest errors and Claude 3.5 the most. The reproducibility analysis indicated that the tests were very repeatable: DeepSeek (100%), GPT-4.1 (97.5%), and Claude 3.5 Sonnet (92%).While LLMs show promise for enhancing diagnostics, ongoing scrutiny is required to address error rates and validate standard medical answers. Given the limited dataset and prompting protocol, findings should not be interpreted as broader equivalence in real-world clinical reasoning. This study demonstrates the need for robust evaluation standards, attention to error rates, and further research.