The role of usability, usefulness and frame in persuasive health communication

Background: A large proportion of ill-health is preventable (Signorelli 1993). A goal for health promoters is to provide information about health risks with the aim of persuading individuals to modify their behaviour. Previous research suggests that the readability of many health promotion materials is too low for effective comprehension. Evidence suggests that much of the health information available is written at a level that is too difficult for the target populations (e.g. Dollahite et al. 1996, Meade & Byrd 1989, Greenfield et al. 2005). Whilst this work is useful in identifying barriers to accessibility to health information, there has been little research that systematically explores the concept of usability within the context of health information. Objectives: The first objective of the thesis was to examine whether the concepts of usability and usefulness as outlined in the Technology Acceptance Model (Davis 1993) can be applied to the domain of health promotion and used to predict intentions to follow the advice given in health promotion leaflets. Second, the studies sought to make distinctions between subjective and objective usability and to explore the factors underlying subjective ratings of the usability of health information. Further, the thesis sought to demonstrate that both objective and subjective usability would influence the persuasive effect of health promotion materials. Finally, using theory from dual-processing models of persuasion (e.g. Elaboration Likelihood Model. Petty and Cacioppo 1986) it was predicted that when usability of leaflets was high, participants would be more likely to make judgements about their intentions to follow the advice given in the leaflets based on peripheral clues such as frame (Tversky and Kahneman 1981, Rothman and Salovey 1997, Levin et al. 1998). Methodology: 5 empirical studies examined the research questions. The first study consisted of two samples from working populations (n=441), and explored manual hand