Article Text

Assessing the effectiveness of antismoking television advertisements: do audience ratings of perceived effectiveness predict changes in quitting intentions and smoking behaviours?
1. Emily Brennan1,
2. Sarah J Durkin2,
3. Melanie A Wakefield2,
4. Yoshihisa Kashima3
1. 1Center of Excellence in Cancer Communication Research, Annenberg School for Communication, University of Pennsylvania, Philadelphia, Pennsylvania, USA
2. 2Centre for Behavioural Research in Cancer, Cancer Council Victoria, Melbourne, Victoria, Australia
3. 3Department of Psychological Sciences, University of Melbourne, Melbourne, Victoria, Australia
1. Correspondence to Dr Emily Brennan, Center of Excellence in Cancer Communication Research, Annenberg School for Communication, University of Pennsylvania, 3620 Walnut Street, Philadelphia, PA 19104, USA; ebrennan{at}asc.upenn.edu

## Abstract

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.

• Social marketing
• Media

## Introduction

Variations in the effectiveness of antismoking mass media campaigns are due in large part to differences in the reach, intensity and duration of campaign exposure.1 However, campaign success may also be related to the content and executional characteristics of the messages used.1 ,2 For this reason, there is a need for methods that can efficiently and effectively determine which messages are most likely to have the desired effects.3 Audience ratings of perceived effectiveness (PE)—which typically tap the extent to which a message has been favourably received and evaluated—may provide one such method.

Confidence in the utility of PE measures has increased recently, as the body of evidence linking PE with measures of actual effectiveness such as attitude4 ,5 and intention change3 ,4 ,6 has grown. In one recent study, the PE ratings given to the four antismoking advertisements to which an individual was exposed (from a range of 100 messages total) were found to predict quitting-related intentions.3 In another recent study, Davis et al6 found that PE ratings predicted several campaign outcomes measured 2 weeks after initial exposure to the message, including greater intentions to quit. However, Davis et al6 did not find PE ratings to be associated with the likelihood that smokers had actually attempted to stop smoking. While evidence of a predictive relationship between PE and changes in behavioural intentions is undoubtedly an important finding, and the link between intentions and behaviours is well established,7 it remains the case that demonstrating an association between PE ratings and subsequent behaviour change would greatly enhance confidence in the use of these measures. As such, in the current study we aimed to provide a further test of the association between the PE ratings given to antismoking television advertisements and the likelihood of subsequent changes in quitting intentions and smoking behaviours.

In explaining why they did not find a significant association between PE and behaviour change, Davis et al6 emphasised that participants received only a low dose of media exposure, and that for many smokers, a 2-week follow-up may not have allowed sufficient time for implementation of their decision to quit. In addition, baseline rates of quitting over a 2-week period are typically low (eg, 5%8), so the Davis et al study may have lacked power to detect differences in the rates of quitting activity. Therefore, given that many smokers relapse within the first week of quitting,9 and some smokers try to reduce their cigarette consumption before making an actual attempt to quit,10 in the current study we more broadly defined behaviour change to include both successful and unsuccessful quit attempts, as well as reductions in cigarette consumption, thereby capturing the activity most likely to occur soon after exposure to an effective antismoking message.

Some studies have found that smokers who are intending to quit tend to give higher PE ratings to antismoking advertisements than those who are uninterested in quitting,11 ,12 a finding which could be taken to indicate that antismoking messages will be most effective for this group.11 On the other hand, it is also possible that PE may not be all that important in determining whether those who are intending to quit are influenced by an advertisement, given that the arguments made in the message are likely to be consistent with their current attitudes. In contrast, those who are not yet planning to quit are likely to require convincing of the merits of the antismoking argument and may therefore only be affected by the advertisements that they perceive to be credible, relevant and motivating. To our knowledge, no previous studies have examined whether the association between PE and campaign outcomes is the same for smokers who are and are not intending to quit (note however that the two recent studies did control for baseline interest in quitting when testing the association between PE and postexposure intentions3 ,6). Therefore, given the practical implications of any such differences for the use of PE measures to pretest antismoking advertisements, in the current study we also examined whether the association between PE ratings and subsequent intention and behaviour change was moderated by baseline intentions to quit.

## Methods

### Sample and procedure

Data were collected as part of a larger study in which current smokers and non-smokers participated in friendship pairs. In this study, a two (advertisement: Pam Laffin or Rick Stoddard—46 Years Old) by two (conversation: no conversation or conversation) experimental design assessed the influence of interpersonal conversations on campaign effectiveness. For the purposes of the current study, however, participants from the four experimental conditions were combined, and the sample was restricted to the 231 current smokers. Additional information about the design, sample and procedures of the experimental study can be obtained from the authors.

## Results

### Descriptive data

At Time 1, 88.7% of smokers were not planning to quit. Overall, the ADPE scale had a mean of 3.6 (SD=1.0), and the PPE scale had a mean of 3.4 (SD=1.0). Preliminary linear regression models indicated that those who had no PTQ at Time 1 (M=3.6; SD=1.0) and those who were planning to quit (M=3.8; SD =0.9) gave similar ADPE scores, β=0.21, 95% CI (−0.16 to 0.57), p=0.267. However, compared with those who were not planning to quit (M=3.4; SD=1.0), those who were (M=3.9; SD=0.8) gave significantly higher PPE scores, β=0.50, 95% CI (0.14 to 0.86), p=0.007. From Time 1 to Time 2, 18.2% of participants changed their intentions to quit, and at follow-up, just over a quarter (26.4%) reported that they had changed their smoking behaviour.

### Models predicting changes in quitting intentions and smoking behaviour

Table 2 presents the results from analyses predicting intention change. ADPE and PPE were both significantly associated with intention change in the unadjusted and multivariable models. The two-way interaction between PTQ and ADPE was not significant, and the interaction with PPE was only approaching statistical significance. In the final multivariable model, only PPE was significantly associated with intention change. A two-way interaction between ADPE and PPE was also tested (not shown in table 2), but this interaction term was not significant, OR=1.40, 95% CI (0.91 to 2.16), p=0.126.

Table 2

Logistic regression models predicting changes in quitting intentions and smoking behaviour

Table 2 also presents the findings from analyses predicting changes in smoking behaviour. ADPE was not associated with the likelihood of behaviour change, and the two-way interaction with PTQ was also not significant. However, PPE was significantly associated with the likelihood of behaviour change (the interaction between PTQ and PPE was not significant; table 2). Consistently, PPE was the only significant predictor in the final multivariable model predicting behaviour change, and the two-way interaction between ADPE and PPE was not statistically significant (not shown in table 2; OR=1.04, 95% CI (0.73 to 1.50), p=0.819). One additional model examined the association between intention change and behaviour change. After adjusting for PTQ, smokers who changed their intentions between Time 1 and Time 2 were significantly more likely to make a subsequent change to their behaviour (40.0%, compared with 23.7% for those who did not change their intentions), OR=2.41, 95% CI (1.10 to 5.31), p=0.029.

## Discussion

Audience ratings of PE have been used in studies to compare the effectiveness of different types of antismoking messages,6 ,11 ,12 ,16 ,21–23 and have been recommended as a hurdle requirement that should be satisfied before messages are broadcast to a population.24 Building on recent findings of an association between PE and changes in message-relevant attitudes4 ,5 and intentions,3 ,6 in the current study we found that antismoking advertisements were more likely to produce a change in intention when smokers perceived the advertisement to be effective. We also found, for the first time, that perceptions of the personalised effectiveness of a message predicted the likelihood of individuals making positive changes in their smoking behaviour. As such, these findings further endorse the use of PE measures to pretest and evaluate antismoking advertisements.

Somewhat consistent with previous studies,11 ,12 we found that smokers who were planning to quit at baseline gave higher ratings on the PPE scale than did non-intenders. While this finding could indicate that antismoking messages may be most effective for those who are already planning to quit,11 the results from the interaction analyses did not provide any evidence that the associations between PE and changes in intentions and behaviours were moderated by baseline interest in quitting. As such, the current findings indicate that, while baseline interest in quitting should be used as a control variable when assessing the association between PE ratings and quitting outcomes, it may not be necessary to consider the baseline quitting intentions of the sample when using PE ratings to decide which messages should be aired in a given population.

Antismoking mass media campaigns are increasingly being recommended as a key component of comprehensive tobacco control programmes,26–28 and evidence of their effectiveness at the population level continues to grow.1 With this increased use comes the need for methods that can guide decisions about which antismoking messages should be aired. By demonstrating that PE measures—and in particular, measures that tap the extent to which a smoker has been personally affected by a message—may predict subsequent changes in quitting intentions and smoking behaviours, the current study provides further evidence supporting the use of PE ratings to assess the potential effectiveness of antismoking television advertisements.

### What this paper adds

• Perceived effectiveness measures may provide an efficient method by which to pretest and evaluate antismoking messages, but only to the extent that these measures are associated with indicators of actual effectiveness, such as intention and behaviour change. Consistent with the findings from two recent studies, in this study we found that changes in intentions to quit following exposure to an anti-smoking advertisement were predicted by audience ratings of personalised perceived effectiveness. We also found, for the first time, that changes in smoking behaviour were also predicted by personalised perceived effectiveness ratings. By demonstrating that smokers who perceived that they had been personally affected by the advertisement were then more likely to change their quitting intentions and smoking behaviour, these findings provide important evidence supporting the use of perceived effectiveness ratings to guide decisions about which antismoking messages should be aired.

## Footnotes

• Correction notice This article has been corrected since it was published Online First. The *** p value indicators in the Table 2 body have been changed to *, and the * p value indicators have been changed to ***.

• Contributors EB designed the study, analysed and interpreted the data and led the writing of all drafts. SJD, MAW and YK assisted in the design of the study, oversaw data analysis and contributed to the interpretation of the data and all drafts. All authors gave final approval of the manuscript.

• Funding This research was supported by an Australian Research Council Linkage Grant LP0882363 awarded to YK at the University of Melbourne, and SJD and MAW at the Cancer Council Victoria. The Australian Research Council had no involvement in the study design; in the collection, analysis and interpretation of data; in the writing of the report; or in the decision to submit the paper for publication.

• Competing interests All authors have completed the Unified Competing Interest form at http://www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: EB, SJD, MAW and YK had support, in the form of grant funding, from the Australian Research Council for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous 3 years; and no other relationships or activities that could appear to have influenced the submitted work. This study was conducted while EB was a PhD candidate at the University of Melbourne and the Cancer Council Victoria.

• Ethics approval University of Melbourne's Human Research Ethics Committee.

• Provenance and peer review Not commissioned; internally peer reviewed.

• Data sharing statement Readers are encouraged to contact the authors for further information regarding the data.

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