Abstract
Ankylosing Spondylitis (AS) is a complex autoimmune disease for which early diagnosis and treatment are critical for prognosis. The quality of health information shared on social media significantly impacts patient education. This study aims to evaluate the quality and completeness of AS-related health information on 2 major Chinese video platforms, TikTok and Bilibili. On August 27, 2025, a cross-sectional study was conducted, retrieving and analyzing the top 100 AS-related videos (N = 200) from each platform. Video reliability was assessed using the DISCERN tool and JAMA, and video quality was assessed using GQS and the 6-Dimensional Content Integrity Scale. Bilibili was found to be significantly superior to TikTok only in academic rigor (defined as information reliability and source transparency, measured by DISCERN-Dimension 1 and JAMA; P < .001), while both platforms performed poorly in practical utility (defined as content completeness and instructional value for patients, measured by GQS and DISCERN-Dimension 2; P > .05). Video "quality" was found to be completely uncorrelated with "popularity" (eg, likes, favorites) (P > .05), while video duration was the only significantly correlated external factor (rho = .41, P < .001). Content completeness exhibited a "cancelation effect" (Referring to the complementary nature of content strengths across platforms where one excels in areas the other lacks. Bilibili excelled in "diagnosis," while TikTok excelled in "treatment"). Notably, orthopedists and other healthcare professionals (HCPs; 59.5%) were the main content creators, not rheumatologists (27%). On Bilibili, the "patient" group scored significantly higher in "treatment information" (Dim2) than the "rheumatologist" group (P = .029). Bilibili provides more academically rigorous AS information, but both platforms severely lack depth in core practical content, and platform algorithms fail to effectively screen for high-quality content (quality-popularity disconnect). The video ecosystem (eg, "orthopedist-dominated" and "professionalism inversion" [a phenomenon where patient-led narratives outperformed specialists in treatment-related metrics due to the inherent structural alignment between comprehensive personal storytelling and traditional assessment criteria].) profoundly reflects real-world diagnostic dilemmas and the limitations of traditional assessment tools in the modern video era.