Development and validation of the Perceived Effectiveness of Nutrition Messages Scale.

An understanding of the extent to which target audiences consider different nutrition-related messages to be effective could assist campaign developers design more persuasive communications. Accordingly, this study sought to develop and assess the utility of the Perceived Effectiveness of Nutrition Messages Scale (PENMS). A longitudinal online survey was completed by Australian adults (n = 5,014 at Time 1 and 2,880 at Time 2). At T1, respondents saw one of two messages promoting healthy eating. They were then administered the PENMS, and asked how likely they were to engage in the behaviour specified in the message. Respondents completed the PENMS again at T2. An exploratory factor analysis was performed on PENMS scores and measures of reliability and validity obtained. Two factors were identified: 'effects perceptions' (Factor 1) and 'message perceptions' (Factor 2). Internal consistency of scores was 0.82 for Factor 1 and 0.70 for Factor 2. Test re-test reliability was 0.76 and 0.69 for Factors 1 and 2, respectively. Scores on both factors were moderately correlated with behavioural intentions. The favourable results for PENMS scores suggest the scale may be a useful tool for assessing the extent to which target audiences consider different nutrition-related messages to be effective.