Using efficacy cues in persuasive health communication is more effective than employing threats – An experimental study of a vaccination intervention against Ebola
Authors: Ort Alexander , Fahr Andreas 
Published: April 2018

ObjectivesAlthough much effort has been made to study fear appeals in persuasive health communication, there is still mixed support for the effectiveness of this approach. Therefore, this research investigated the effect of invoked fear via health communication messages on crucial components of the Extended Parallel Process Model (EPPM) by focusing on the rarely examined interaction between perceptions of threat and efficacy and their effects on fear control and danger control processes as well as health‐relevant outcomes.DesignWe recruited 447 participants (Mage = 32.00 years; 64% female) for a 2 × 2 between‐subjects experimental study via quota sampling. While completing an online questionnaire, subjects were randomly assigned to view one of four versions of a mock website containing information about vaccinations against Ebola virus disease (EVD), which varied in threat and efficacy.MethodsAfter seeing the stimulus, participants completed assessments of their perceptions of threat and efficacy, evoked fear, adaptive and defensive responses to the presented message, attitudes, and intentions. Structure equation modelling (SEM) was used to analyse the relationships within the model (EPPM).ResultsPromoting efficacy with respect to EVD was more effective than emphasizing threat, resulting in danger control rather than fear control processes. Although threat may be effective in attracting peoples’ attention, there is a comparatively small effect of evoked fear on attitudes and intentions.ConclusionsThe data support the assumption that there is an important association between threat and coping appraisals facilitating behaviour change. Moreover, the widely held notion that people have to be scared or threatened to encourage attitude and behaviour changes should be treated with caution. Communication should instead focus on efficacy to foster adaptive responses.
Statement of contribution

What is already known on this subject?

There is mixed support for the effectiveness of fear appeals in persuasive health communication, especially regarding the interaction of threat perceptions and coping appraisals for fear and danger control processes.

The Extended Parallel Process Model – being a current and often applied model to investigate the effects of fear appeals – suggests a multiplicative relationship between threat perceptions and coping perceptions

Most studies applying conventional analysis strategies (e.g., [M] ANOVAs) indicate that perceptions and appraisals of threat and efficacy are not directly related to each other.

What does this study add?

It demonstrates the parallelism and interaction between threat appraisal and coping appraisal processes and demonstrates the usefulness of SEM in testing associations within the EPPM.

It confirms the assumption of an important multiplicative association between threat and coping appraisals within the EPPM, while related cognitive processes still seem to operate independently.

Adaptive responses to persuasive messages are mainly triggered using efficacy cues, not threat, which could also be triggered by promoting positive emotional experiences (e.g., gain‐framing or entertainment education).