Content accuracy and reliability of myocarditis-related information on short-video platforms: A cross-sectional study of BiliBili and TikTok

Background Short-video platforms are increasingly used by the public to access medical information, yet the quality and educational value of myocarditis-related content remain insufficiently studied. This study evaluated the quality, reliability, understandability, actionability, and dissemination characteristics of myocarditis-related short videos on Bilibili and TikTok, with comparisons across platforms, video formats, and uploader types. Methods A cross-sectional content analysis was conducted on February 5, 2026. Videos were identified on Bilibili and TikTok using the Chinese term “心肌炎.” After screening, 253 eligible videos were included. Data on video characteristics, engagement metrics, uploader identities, and thematic coverage were extracted. Video quality was assessed using GQS, JAMA benchmark criteria, mDISCERN, VIQI, and PEMAT. Group comparisons and Spearman correlation analyses were performed. Results Of the 253 videos, 121 were from Bilibili and 132 from TikTok. Expert monologues were the most common format (51.0%). Significant differences in quality-related scores were observed across video formats. Course- and literature-based videos achieved higher GQS, VIQI, and JAMA scores, whereas expert monologues showed relatively higher mDISCERN scores. TikTok videos had higher mDISCERN and JAMA scores and greater engagement, while Bilibili videos were longer and more understandable according to PEMAT-U. Videos uploaded by medical professionals generally performed better in quality and reliability assessments than those uploaded by nonprofessionals. Engagement indicators were strongly intercorrelated but showed limited correlation with quality measures. Prevention, complications/prognosis, and long-term follow-up or recovery guidance were insufficiently addressed. Conclusions Myocarditis-related short videos on Bilibili and TikTok showed considerable variation in dissemination performance but generally limited quality and reliability. High popularity did not necessarily correspond to high informational value. Greater involvement of healthcare professionals, improved source transparency, and platform-tailored communication strategies may help enhance the quality and usefulness of myocarditis-related health information.