Quality, reliability, and accountability of patellofemoral pain-related short videos on three Chinese social media platforms: a cross-sectional comparative study

Patellofemoral pain (PFP) is a common cause of anterior knee pain, but the quality of related short-video information remains unclear. This cross-sectional study evaluated PFP-related videos on BiliBili, Douyin, and Rednote. Using one formal Chinese query, we screened the first 100 default-ranked videos per platform on 5 March 2026. After removing six repeated URL occurrences and reconciling five duplicated URL clusters to single adjudicated values, 184 unique within-platform listings were analysed, of which 12 probable cross-platform repost clusters (26 listings) were retained in the primary analysis. Video characteristics and engagement were extracted, and two raters independently assessed quality, reliability, and accountability using the Global Quality Score (GQS), modified DISCERN (mDISCERN), and Journal of the American Medical Association (JAMA) criteria. Median GQS, mDISCERN, and JAMA scores were 2 (IQR 2–3), 2 (IQR 2–3), and 2 (IQR 2–2), respectively. Overall, 11.4% achieved a GQS of 4 or 5, and none met all four JAMA criteria. Douyin scored higher than BiliBili on GQS and mDISCERN; Douyin and Rednote scored higher than BiliBili on JAMA. Uploader subgroup findings were exploratory, and engagement–score associations varied by platform. Pre-adjudication agreement was strong for GQS (weighted κ = 0.869) and good for mDISCERN (ICC = 0.804) and JAMA (ICC = 0.847). The findings represent one query at one time point and do not assess factual accuracy.