Participant responses to ‘What is your best guess as to the percent chance that John actually had COVID-19 at the time of his test, given his test result?’, by message viewed
| Message viewed | N answering 48%–52% (percentage, 95% CI52) | N answering categorically (0% or 100%) (percentage, 95% CI52) |
| Control | 84/356 23.6% (19.5% to 28.3%) | 42/356 11.8% (8.8% to 15.6%) |
| USA | 98/342 28.7% (24.1% to 33.7%) | 42/342 12.3% (9.2% to 16.2%) |
| New Zealand | 66/345 19.1% (15.3% to 23.6%) | 20/345 5.8% (3.7% to 8.8%) |
| UK | 97/343 28.3% (23.8% to 33.3%) | 68/343 19.8% (15.9% to 24.4%) |
| Experimental | 98/358 27.4% (23% to 32.2%) | 41/358 11.5% (8.5% to 15.2%) |