COVID-19 myth-busting: an experimental study.

Background: COVID-19 misinformation is a danger to public health. A range of formats are used by health campaigns to correct beliefs but data on their effectiveness is limited. We aimed to identify A) whether three commonly used myth-busting formats are effective for correcting COVID-19 myths, immediately and after a delay, and B) which is the most effective.

Methods: We tested whether three common correction formats could reduce beliefs in COVID-19 myths: (i) question-answer, ii) fact-only, (ii) fact-myth. n = 2215 participants (n = 1291 after attrition), UK representative of age and gender, were randomly assigned to one of the three formats. n = 11 myths were acquired from fact-checker websites and piloted to ensure believability. Participants rated myth belief at baseline, were shown correction images (the intervention), and then rated myth beliefs immediately post-intervention and after a delay of at least 6 days. A partial replication, n = 2084 UK representative, was also completed with immediate myth rating only. Analysis used mixed models with participants and myths as random effects.

Results: Myth agreement ratings were significantly lower than baseline for all correction formats, both immediately and after the delay; all β's > 0.30, p's < .001. Thus, all formats were effective at lowering beliefs in COVID-19 misinformation. Correction formats only differed where baseline myth agreement was high, with question-answer and fact-myth more effective than fact-only immediately; β = 0.040, p = .022 (replication set: β = 0.053, p = .0075) and β = - 0.051, p = .0059 (replication set: β = - 0.061, p < .001), respectively. After the delay however, question-answer was more effective than fact-myth, β = 0.040, p =. 031.

Conclusion: Our results imply that COVID-19 myths can be effectively corrected using materials and formats typical of health campaigns. Campaign designers can use our results to choose between correction formats. When myth belief was high, question-answer format was more effective than a fact-only format immediately post-intervention, and after delay, more effective than fact-myth format.