Quality of Colorectal Cancer Information on Douyin (TikTok's Chinese version) and Bilibili in China: A Cross-Sectional Content Analysis
This cross-sectional content analysis reveals that while Douyin and Bilibili offer similar general quality and reliability for colorectal cancer information, Bilibili provides more comprehensive disease-specific details, with video length positively correlating to completeness while popularity and search rank fail to serve as reliable quality indicators.
Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer
Every day, millions of people turn to their phones to find answers about their health. When a diagnosis like colorectal cancer appears, the search often begins not in a doctor's office, but on short-video platforms where information flows as fast as a scrolling feed. These digital spaces have become a primary source of medical knowledge, yet the way they deliver content is shaped by algorithms designed to keep viewers watching, not necessarily by a commitment to clinical accuracy. The core question for anyone navigating this landscape is simple: does a video that is popular, polished, or easy to find actually contain the complete and reliable information a patient needs to understand their condition?
Researchers set out to answer this by comparing two of China's most prominent video platforms: Douyin, known for its rapid, short-form content, and Bilibili, which hosts longer, more archival-style videos. They focused specifically on colorectal cancer, a disease that remains a leading cause of illness and death worldwide. The team was not interested in how many likes a video received or how high it appeared in a search list. Instead, they wanted to measure the actual substance of the information. They looked for three specific qualities: how well the video was presented, whether the sources were reliable, and most importantly, whether the video covered the essential facts about the disease, such as its causes, symptoms, and treatment options.
To conduct this investigation, the researchers performed a systematic sweep of both platforms on a single day. They logged out of their accounts to ensure they were seeing the default search results that any new user would encounter. They typed in the Chinese term for colorectal cancer and recorded the first 110 videos that appeared on each site. From this initial pool, they filtered out duplicates and irrelevant clips, leaving a final set of 170 videos to analyze. Two medical experts then watched every single video independently, scoring them against a strict checklist. This checklist included seventeen specific items that a complete explanation of colorectal cancer should cover, ranging from dietary habits and genetic risks to the specifics of surgery and recovery. They also evaluated the videos for clarity and whether they acknowledged the limits of current medical knowledge.
The results revealed a clear distinction between the two platforms, one that defies the assumption that popularity equals quality. While the videos on both sites were generally well-presented and appeared to come from credible sources, Bilibili offered significantly more complete information. The videos on Bilibili were longer, averaging nearly five minutes, compared to roughly two and a half minutes on Douyin. This extra time allowed them to cover more ground. Specifically, Bilibili videos were more likely to explain the causes of the disease and describe the symptoms in detail, covering about one additional topic from the checklist on average. In contrast, the shorter videos on Douyin, while engaging, often skipped these critical details.
Perhaps the most surprising finding was that the metrics usually used to judge success on social media had no connection to the quality of the medical advice. The number of likes, comments, and shares a video received did not predict whether it contained accurate or complete information. Similarly, a video's position in the search results did not guarantee it was a better resource. A highly popular video could be missing key facts about prevention or treatment, while a less viewed video might offer a thorough explanation. The researchers found that the only factor that reliably signaled a more complete video was its length; longer videos tended to cover more of the necessary topics.
The study also examined who was posting these videos. It turned out that specialist physicians were the most common creators on both platforms, contributing nearly 60 percent of the content. However, the source of the video did not guarantee a higher score. Videos uploaded by doctors were not consistently more complete or reliable than those from other creators. This suggests that simply having a medical title is not enough; the content itself must be structured to ensure all vital information is included.
Ultimately, the research highlights a gap between the way these platforms function and the needs of patients seeking health information. The algorithms that prioritize engagement and speed are not designed to ensure that a viewer learns everything they need to know about a complex disease. A polished, fast-moving video can be entertaining and easy to watch, but it may leave out the very details that help a person recognize risk factors or understand their treatment options. The findings suggest that for high-stakes health topics, the length and depth of a video matter more than its popularity, and that viewers should be cautious about assuming that a top-ranked or highly shared video is the most trustworthy source of medical truth.
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