Does viewing false messages about e-cigarette harms on Twitter change current smokers' perceptions of e-cigarettes in the US and the UK? A randomised controlled experiment

Measured pre-exposure (baseline) and post-exposure:
1. Smoking cessation contemplation ladder: participants provide a score reflecting their likelihood of quitting smoking from 0 (no thought of quitting) to 10 (taking action to quit)
2. Risk perceptions of combustible tobacco: participants were asked to give a score reflecting the likelihood that smoking combustible tobacco will result in lung cancer, heart disease, mouth or throat cancer, chronic obstructive pulmonary disorder (COPD) and stroke from 1 (extremely unlikely) to 5 (extremely likely)
3. Risk perceptions of electronic cigarettes: participants were asked to give a score reflecting the likelihood that smoking combustible tobacco will result in lung cancer, heart disease, mouth or throat cancer, chronic obstructive pulmonary disorder (COPD) and stroke from 1 (extremely unlikely) to 5 (extremely likely)
4. Perceived relative harm of e-cigarettes compared to smoking regular cigarettes: participants were asked: Compared to smoking regular cigarettes, would you say that e-cigarettes/vapes are much less harmful (1) - much more harmful (5).
5. Intentions to purchase electronic cigarettes in the next month: How probable is it that you will purchase an e-cigarette/vape in the next month? 0 (no chance) to 10 (certain)
6. Knowledge about electronic cigarettes: participants’ given statement about e-cigarettes e.g. E-cigarettes do not contain any of the toxic chemicals that can be found in regular cigarettes and asked if the statement is (1) true, (20) false, or (3) don’t know.

1. Perceived effectiveness of exposure condition: participants' were asked after viewing each exposure to rate how much they disagree or agree with the following statements about the message they just saw: this message is worth remembering, this message grabbed my attention, this message is powerful, this message is informative, this message is meaningful to me, this message is convincing.
2. Intentions to reply/retweet/like/share message (Tweets): participants were asked after each exposure are you likely to reply/retweet/like/share this message.
3. Emotional responses to exposure condition: participants were asked after each exposure: when thinking about e-cigarettes, does the message you just saw make you feel: scared, hopeful, worried, happy, angry, relieved
4. Self-efficacy to quit smoking, participants were asked at the end of the questionnaire: How confident are you that you can quit using tobacco? Not at all confident, Not very confident , Somewhat confident , Confident , Very confident & Completely confident
5. Prior exposure to e-cigarette misinformation, participants were asked at the end of the questionnaire
6. Level of trust for information on e-cigarettes: participants were asked at the end of the questionnaire
7. Exposure to conflicting information about e-cigarettes: participants were asked at the end of the questionnaire
8. Information seeking about e-cigarettes: participants were asked at the end of the questionnaire
9. Perceived addictiveness of cigarettes and e-cigarettes: participants were asked at the end of the questionnaire
10. Social media and internet use: participants were asked at the end of the questionnaire
11. Self-identity; participants were asked: How much do you agree or disagree with each of the following statements: I am very sensitive to criticism by others. Answers: strongly disagree (1) - strongly agree (5). Measured once, post-exposure.
12. Epistemic beliefs about facts and science: participants' were asked a series of questions about their intuition, need to see evidence and beliefs about how truth/facts and power/politics interact. Measured once, post-exposure.