Investigation of Misleading Techniques Used in Online Fluoride Misinformation

Fluoride misinformation can fuel anti-fluoridation movements, influencing political decisions and dental treatment choices. This study aimed to elucidate the misleading techniques used to produce online fluoride misinformation.

Two independent investigators searched scientific databases for references that supported or refuted 33 fluoride misinformation messages, derived from a prior study that manually identified dental falsehoods on websites through thematic content analysis. The levels of evidence were assessed according to the Oxford Centre for Evidence-Based Medicine (levels 1-5) and the GRADE guidelines (high to very low, indicating the degree of confidence that the direction of the net effect is correct). Misleading techniques were classified as false attribution, when no reference supported a message, or quote mining, when at least one supporting reference was identified but used out of context.

Nineteen references were identified to refute 27 fluoride misinformation, while seven references were identified to support six misinformation messages. False attribution was the predominant technique (81.82%), compared to quote mining (18.18%). The levels of evidence and strength of recommendations for refuting references ranged from 1A-1B (high, 31.6%) to 2C-5 (very low, 57.9%). Supporting references ranged from 2B (low, 14.3%) to 2C-5 (very low, 85.7%). The claim 'fluoride accumulates in the body' was the only one supported by low-level evidence.

Online fluoride misinformation is most often grounded in false attribution. Understanding the strategies that authors use to construct these false messages can support health educators in creating more targeted and effective prebunking and debunking interventions.