Principal Results
INFECTIOUS DISEASES
Trust is key in any communication [The inclusion of a call to action at the end of the message also increased trust. The inclusion of a call to action may impact the level of cognitive processing by leading to elaborations, which might increase the feeling of knowing and hence trust. Notably, the use of a call to action is not unproblematic, seen from a health communication perspective. Multiple papers comment on the importance of being neutral when handing over information so that recipients can make informed choices—“strive to inform, never persuade” [Comprehension, on the other hand, was not significantly affected by whether the source was a formal field expert or a nonexpert. This is in line with previous works regarding the source as a potential determinant of comprehension [As with comprehension, intention to follow the pandemic recommendations was not influenced by whether the source was a field expert or a nonexpert. More surprisingly, however, although the inclusion of a call to action increased comprehension, it did not increase intention. Although the factorial ANOVA showed a main effect of the topic of intentions to follow recommendations, the pairwise comparisons did not yield any statistically significant difference between the 3 topics. That is, none of the investigated variables were found to have an effect on intention.As the intended outcome of health communication during a public health crisis like a pandemic is often not merely informing the public but also wanting them to act in a certain way in order to reduce risk for themselves and society, some of our findings might come across as depressing. Greater intention to follow pandemic recommendations was expected if the communication comes from an infectious diseases specialist with respect to a sales consultant. Furthermore, also the inclusion of a call to action was expected to lead to greater intention to follow recommendations. Both these factors increase trust in our experiment, but, alas, not intention. On the other hand, we observed little variation in the data, along with a ceiling effect. The mean value for intention to follow the recommendations was 5.56 on a 1-6 scale, with a group mean ranging from 5.44 to 5.67 (high to low ratio equal to 1.04). The small variation in the data might hide the investigated effects. Further research in different contexts is encouraged.As with intention, neither the topic nor the inclusion of a call to action had a significant impact on behavior. As behavior is a “harder” outcome than mere intentions, this comes as no surprise. The source, however, had a statistically significant impact on behavior, with the nonexpert source leading to an increase of 5.7% in the number of people who decided to fill in their email addresses in order to continue being part of the pandemic research project. Although this can be explained by a higher identification of participants with a nonexpert source compared with a field expert, this finding requires careful interpretation. First, as opposed to the high mean for intention, the mean for behavior was relatively low (0.30 on a 0-1–point scale), with a group mean ranging from 0.20 to 0.37. Second, the proxy used to measure behavior—asking participants to fill in their email address to receive updates and advice—might be inaccurate in measuring the desired construct. As most indirect measures, caution is required in drawing conclusions. The literature is scarce in this point. A recent literature review revealed that only a handful of studies assessing the association between health communication and actual behavior have been carried out [