Assessing the effectiveness of antismoking television advertisements: do audience ratings of perceived effectiveness predict changes in quitting intentions and smoking behaviours?

Background Decisions about which antismoking advertisements should be aired are often guided by audience ratings of perceived effectiveness (PE). Given that the usefulness of PE measures depends on their ability to predict the likelihood that a message will have a positive impact on outcomes such as behaviour change, in the current study we used pre-exposure, postexposure and follow-up measures to test the association between PE and subsequent changes in quitting intentions and smoking behaviours. Methods Daily smokers (N=231; 18 years and older) completed baseline measures of quitting intentions before watching an antismoking advertisement. Immediately following exposure, intentions were measured again and PE was measured using six items that factored into two scales: ad-directed PE (ADPE) and personalised PE (PPE). A follow-up telephone survey conducted within 3 weeks of exposure measured behaviour change (reduced cigarette consumption or quit attempts). Results From pre-exposure to postexposure, 18% of smokers showed a positive change in their intentions. Controlling for baseline intentions, PPE independently predicted intention change (OR=2.57, p=0.004). At follow-up, 26% of smokers reported that they had changed their behaviour. PPE scores also predicted the likelihood of behaviour change (OR=1.93, p=0.009). Conclusions Audience ratings of PPE, but not ADPE, were found to predict subsequent intention and behaviour change. These findings increase confidence in the use of PE measures to pretest and evaluate antismoking television advertisements, particularly when these measures tap the extent to which a smoker has been personally affected by the message.