Levels of trust in risk-only negative health messages issued by public agencies: a quantitative research-based mindsponge framework

Trust in messengers is essential for a public agency to ensure effective benefit-risk communication. However, there is insufficient research on the difference in trust between risk-only or benefit-and-risk messages that deal with negative topics. To clarify these differences, this study used three radiation topics to determine the best benefit-risk communication design. We conducted a randomized comparative study in November 2020 on 1100 Japanese individuals (550 men and 550 women), who were allocated either to the risk message group (risk-only) or the benefit-and-risk message group (benefit-and-risk). The questionnaire focused on the trust level in a public agency for each message. We conducted an independent sample t -test using the trust mean at the time of registration. There were significant differences in the trust level in the public agency for all three topics ( p < 0.001). The trust level was ranked as risk-only, followed by benefit-and-risk; however, the trust level was still high enough when the trust level at baseline was high from the outset. In risk-only communication on negative topics, perceptions were consistent with the types of risk message due to confirmation bias. Hence, trust in risk-only negative health messages promoted a preferential higher information absorptivity under the mindsponge mechanism. However, effective benefit-risk communication is assured by high trust levels between a public agency and the public, so it is important to consistently build trust with all stakeholders on a regular basis.