MythTriage: Scalable Detection of Opioid Use Disorder Myths on a Video-Sharing Platform

Understanding the prevalence of misinformation in health topics online can inform public health policies and interventions. However, measuring such misinformation at scale remains a challenge, particularly for high-stakes but understudied topics like opioid-use disorder (OUD)-a leading cause of death in the U.S. We present the first large-scale study of OUDrelated myths on YouTube, a widely-used platform for health information. With clinical experts, we validate 8 pervasive myths and release an expert-labeled video dataset. To scale labeling, we introduce MYTHTRIAGE, an efficient triage pipeline that uses a lightweight model for routine cases and defers harder ones to a high-performing, but costlier, large language model (LLM). MYTHTRIAGE achieves up to 0.86 macro F1-score while estimated to reduce annotation time and financial cost by over 76% compared to experts and full LLM labeling. We analyze 2.9K search results and 343K recommendations, uncovering how myths persist on YouTube and offering actionable insights for public health and platform moderation. 1 Warning: Some content of this paper, included to contextualize our data, is misleading. 1. Data Collection 2. Data Labeling for OUD-Related Myths 1.1: Curating Opioid Topics and Queries Google Trends YouTube Autocomplete Fentanyl 8 Topics Kratom … 73 Queries fentanyl overdose fentanyl … 1.2: Collecting Data on YouTube Collecting Search Results Queries Collect Top-10 Results OUD Search Dataset (2.9K results) Repeat x4 Search Filter Collecting Recommendation Results (Recs.