Effects of Prior Exposure to Conflicting Health Information on Responses to Subsequent Unrelated Health Messages

To accomplish these aims, an online survey-based experiment using a population-based sample of U.S. adults (anticipated N=1,800) will be conducted. At 2 time points across a 28-day period, participants will be exposed to news stories and social media posts about 6 health topics: mammography screening, prostate-specific antigen (PSA) testing, Vitamin D supplementation, carbohydrate consumption, alcohol consumption, and breastfeeding. Participants will be randomized to 1 of 2 treatment groups that differ only in the amount of conflict presented in these news and social media posts (conflict, no conflict). At a third time point, after the exposure to conflict period, all participants will be exposed to 3 (out of a possible 9) messages from existing health campaigns about 3 behaviors for which there is scientific consensus: fruit and vegetable consumption, colorectal cancer screening, and physical activity. To assess carryover effects (Primary Aim), participants' receptivity to these messages-as measured through several affective and cognitive responses (e.g., confidence in the evidence presented)-will be measured. Message receptivity is expected to be lower among those who were randomized to receive conflicting health information. Individual-level differences in message receptivity are possible; thus exploratory analyses (Secondary Aim) will be conducted to assess whether carryover effects of exposure to conflict may be more pronounced among certain groups (e.g., those with greater trust in media sources, those of lower socioeconomic position).