Abstract
BACKGROUND: The management of acute ischemic stroke (AIS) is time-sensitive, yet prehospital delays remain prevalent. The application of large language models (LLMs) for medical text analysis may play a potential role in clinical decision support. We assess the performance of LLMs on prehospital AIS and large vessel occlusion (LVO) stroke screening. METHODS: This retrospective study sourced cases from the electronic medical record database of the emergency department (ED) at Maoming People's Hospital, encompassing patients who presented to the ED between June and November 2023. We evaluate the diagnostic accuracy of GPT-3.5 and GPT-4 for the detection of AIS and LVO stroke by comparing the sensitivity, specificity, accuracy, positive predictive value, negative predictive value, and positive likelihood ratio and AUC of both LLMs. The neurological reasoning of LLMs was rated on a five-point Likert scale for factual correctness and the occurrence of errors. RESULT: On 400 records from 400 patients (mean age, 70.0 years ± 12.5 [SD]; 273 male), GPT-4 outperformed GPT-3.5 in AIS screening (AUC 0.75 (0.65-0.84) vs 0.59 (0.50-0.69), P = 0.015) and LVO identification (AUC 0.71 (0.65-0.77) vs 0.60 (0.53-0.66), P < 0.001). GPT-4 achieved higher accuracy than GPT-3.5 in screening of AIS (89.3% [95% CI: 85.8, 91.9] vs 86.5% [95% CI: 82.8, 89.5]) and LVO stroke identification (67.0% [95% CI: 62.3%, 71.4%] vs 47.3% [95% CI: 42.4%, 52.2%]). In neurological reasoning, GPT-4 had higher Likert scale scores for factual correctness (4.24 vs 3.62), with a lower rate of error (6.8% vs 24.8%) than GPT-3.5 (all P < 0.001). CONCLUSIONS: The result demonstrates that LLMs possess diagnostic capability in the prehospital identification of ischemic stroke, with the ability to exhibit neurologically informed reasoning processes. Notably, GPT-4 outperforms GPT-3.5 in the recognition of AIS and LVO stroke, achieving results comparable to prehospital scales. LLMs are supposed to become a promising supportive decision-making tool for EMS practitioners in screening prehospital stroke.