Objectives Behavior change campaigns typically try to change beliefs that influence behaviors, with targeted beliefs comprising the campaign theme. We present an empirical approach for choosing among a large number of potential themes, and results from the implementation of this approach for campaigns aimed at 4 behavioral targets: (1) preventing smoking initiation among youth, and (2) preventing initiation, (3) stopping progression to daily smoking and (4) encouraging cessation among young adults. Methods An online survey of 13- to 17-year-olds and 18- to 25-year-olds in the United States (US), in which 20 potential campaign themes were represented by 154 beliefs. For each behavioral target, themes were ranked based on the strength of belief-intention and belief-behavior associations and size of the population not already endorsing the beliefs. Results The most promising themes varied across behavioral targets but 3 were consistently promising: consequences of smoking for mood, social acceptance and social popularity. Conclusions Using a robust and systematic approach, this study provides campaign developers with empirical data to inform their selection of promising themes. Findings related to the campaign to prevent initiation among youth informed the development of the US Food and Drug Administration’s “The Real Cost” campaign.

Several message topic selection approaches propose that messages based on beliefs pretested and found to be more strongly associated with intentions will be more effective in changing population intentions and behaviors when used in a campaign. This study aimed to validate the underlying causal assumption of these approaches which rely on cross-sectional belief–intention associations. We experimentally tested whether messages addressing promising themes as identified by the above criterion were more persuasive than messages addressing less promising themes. Contrary to expectations, all messages increased intentions. Interestingly, mediation analyses showed that while messages deemed promising affected intentions through changes in targeted promising beliefs, messages deemed less promising also achieved persuasion by influencing nontargeted promising beliefs. Implications for message topic selection are discussed.