Evaluating the Accuracy of Responses by Large Language Models for Information on Disease Epidemiology.

Purpose: Accurate background epidemiology of diseases are required in pharmacoepidemiologic research. We evaluated the performance of large language models (LLMs), including ChatGPT-3.5, ChatGPT-4, and Google Bard, when prompted with questions on disease frequency.

Methods: A total of 21 questions on the prevalence and incidence of common and rare diseases were developed and submitted to each LLM twice on different dates. Benchmark data were obtained from literature searches targeting "gold-standard" references (e.g., government statistics, peer-reviewed articles). Accuracy was evaluated by comparing LLMs' responses to the benchmark data. Consistency was determined by comparing the responses to the same query submitted on different dates. The relevance and authenticity of references were evaluated.

Results: Three LLMs generated 126 responses. In ChatGPT-4, 76.2% of responses were accurate, which was higher compared to 50.0% in Bard and 45.2% in ChatGPT-3.5. ChatGPT-4 exhibited higher consistency (71.4%) than Bard (57.9%) or ChatGPT-3.5 (46.7%). ChatGPT-4 provided 52 references with 27 (51.9%) providing relevant information, and all were authentic. Only 9.2% (10/109) of references from Bard were relevant. Of 65/109 unique references, 67.7% were authentic, 7.7% provided insufficient information for access, 10.8% provided inaccurate citation, and 13.8% were non-existent/fabricated. ChatGPT-3.5 did not provide any references.

Conclusions: ChatGPT-4 outperformed in retrieving information on disease epidemiology compared to Bard and ChatGPT-3.5. However, all three LLMs presented inaccurate responses, including irrelevant, incomplete, or fabricated references. Such limitations preclude the utility of the current forms of LLMs in obtaining accurate disease epidemiology by researchers in the pharmaceutical industry, in academia, or in the regulatory setting.