Evaluating the Appropriateness, Consistency, and Readability of ChatGPT in Critical Care Recommendations

<b>Background:</b> We assessed 2 versions of the large language model (LLM) ChatGPT-versions 3.5 and 4.0-in generating appropriate, consistent, and readable recommendations on core critical care topics. <b>Research Question:</b> How do successive large language models compare in terms of generating appropriate, consistent, and readable recommendations on core critical care topics? <b>Design and Methods:</b> A set of 50 LLM-generated responses to clinical questions were evaluated by 2 independent intensivists based on a 5-point Likert scale for appropriateness, consistency, and readability. <b>Results:</b> ChatGPT 4.0 showed significantly higher median appropriateness scores compared to ChatGPT 3.5 (4.0 vs 3.0, <i>P</i> < .001). However, there was no significant difference in consistency between the 2 versions (40% vs 28%, <i>P</i> = 0.291). Readability, assessed by the Flesch-Kincaid Grade Level, was also not significantly different between the 2 models (14.3 vs 14.4, <i>P</i> = 0.93). <b>Interpretation:</b> Both models produced "hallucinations"-misinformation delivered with high confidence-which highlights the risk of relying on these tools without domain expertise. Despite potential for clinical application, both models lacked consistency producing different results when asked the same question multiple times. The study underscores the need for clinicians to understand the strengths and limitations of LLMs for safe and effective implementation in critical care settings. <b>Registration:</b> https://osf.io/8chj7/.