Background: Low back pain (LBP) is a prevalent healthcare concern that is frequently responsive to conservative treatment. However, it can also stem from severe conditions, marked by 'red flags' (RF) such as malignancy, cauda equina syndrome, fractures, infections, spondyloarthropathies, and aneurysm rupture, which physicians should be vigilant about. Given the increasing reliance on online health information, this study assessed ChatGPT-3.5's (OpenAI, San Francisco, CA, USA) and GoogleBard's (Google, Mountain View, CA, USA) accuracy in responding to RF-related LBP questions and their capacity to discriminate the severity of the condition. Methods: We created 70 questions on RF-related symptoms and diseases following the LBP guidelines. Among them, 58 had a single symptom (SS), and 12 had multiple symptoms (MS) of LBP. Questions were posed to ChatGPT and GoogleBard, and responses were assessed by two authors for accuracy, completeness, and relevance (ACR) using a 5-point rubric criteria. Results: Cohen's kappa values (0.60-0.81) indicated significant agreement among the authors. The average scores for responses ranged from 3.47 to 3.85 for ChatGPT-3.5 and from 3.36 to 3.76 for GoogleBard for 58 SS questions, and from 4.04 to 4.29 for ChatGPT-3.5 and from 3.50 to 3.71 for GoogleBard for 12 MS questions. The ratings for these responses ranged from 'good' to 'excellent'. Most SS responses effectively conveyed the severity of the situation (93.1% for ChatGPT-3.5, 94.8% for GoogleBard), and all MS responses did so. No statistically significant differences were found between ChatGPT-3.5 and Google Bard scores (p>0.05). Conclusions: In an era characterized by widespread online health information seeking, artificial intelligence (AI) systems play a vital role in delivering precise medical information. These technologies may hold promise in the field of health information if they continue to improve.
