Quality, engagement, and predictive validity of acne-related short videos on Chinese platforms Bilibili and TikTok: A cross-sectional content analysis

Objective To evaluate the informational quality and user engagement of acne-related videos on Bilibili and TikTok, and examine associations with uploader characteristics, disease-related topics, presentation formats, and factors linked to high-quality content. Methods A cross-sectional analysis was conducted on 272 videos (122 from Bilibili, 150 from TikTok) retrieved in May 2025. Video characteristics, uploader types, disease-related topics, and presentation formats were recorded. Quality was assessed using the Journal of the American Medical Association benchmark criteria (JAMA), modified DISCERN instrument (mDISCERN), Global Quality Scale (GQS), and Video Information and Quality Index (VIQI). Engagement metrics (likes, comments, collections, shares) were analyzed. Correlation and predictive modeling were applied to examine associations between quality and engagement. Results Bilibili videos were longer (median 409 s vs 51 s; P < 0.001) and scored higher on VIQI (12.05 ± 2.94 vs 10.90 ± 1.97; P = 0.002). TikTok videos were more often uploaded by verified (68.10% vs 33.33%) and professional accounts (65.52% vs 25.64%), achieved higher JAMA (1.28 ± 0.45 vs 0.92 ± 0.98; P < 0.001) and mDISCERN scores (2.10 ± 0.52 vs 2.02 ± 0.93; P = 0.009), and demonstrated higher daily engagement. High-quality content was primarily produced by verified and professional uploaders, particularly in anatomy/physiology topics and doctor monologues. Official media, epidemiology, and television programs/documentaries achieved the greatest engagement. VIQI and GQS were strongly correlated (ρ = 0.755). VIQI (area under the curve [AUC] 0.922) and collections (AUC 0.901) were the strongest discriminators of high-quality content. Conclusions Acne-related videos on Bilibili and TikTok were generally of suboptimal quality. Bilibili favored coherence and accuracy, while TikTok favored transparency and engagement. Quality assessments outperformed engagement metrics in identifying high-quality content. These findings highlight the need to improve credentialing and promote engaging, evidence-based formats to enhance the reliability and impact of dermatologic information on short-video platforms.