We thank Noar et al. for their comments. We understand their concerns regarding our review of pictorial warnings on cigarette packages in smoking behavior1 and are aware of the potential misuse or misunderstandings that could derive from it. We thus take this opportunity to clarify the issues raised in their letter.
It is true that there is other evidence that supports the efficacy of graphic warnings. Indeed, we acknowledged these in the last section of the introduction2,3 and in the first paragraph of the discussion.4–7 However, the focus of our review was on actual behavior change and not on precursors or intermediate indicators of behavior change. In fact, we clearly mentioned that we “purposely excluded outcomes not related to behavior change, such as those looking at perceptions, attitudes, reactions, knowledge, or even motivation and intention to quit.”1(pe12)
It is also true that heterogeneity across studies makes it difficult to draw insights. This was also acknowledged in the paper, and it was actually the reason for not even attempting to use forest plots to depict results, as these could have misled readers. Instead, we used narrative descriptions. We believe that the limitations to which Noar et al. refer more likely concern the methodological designs and quality of the studies conducted so far on behavior change (that could have underestimated the graphic warning's true impact), rather than to biased selection or misinterpretation of the results presented in our review.
We would also like to clarify that we did not state that pictorial warnings on cigarette packages were unlikely to have much effect. In the abstract, we wrote that “the evidence for or against the use of pictorial warnings on cigarette packages is insufficient, suggesting that any effect of pictorial warnings on cigarette packages on behavior would be modest,”1(pe11) and in the conclusion section of the article we further explained that “it would be modest compared with other tobacco control policies”1(pe28) (e.g. increased taxes or smoking bans), namely, in relative terms.
Finally, we agree with Noar et al. that much work remains to be done, and that the body of literature is growing. Examples of the latter are the last two papers they cite8,9 that were not included in our review, as they were published after the review study period.
We hope that our review encourages researchers to produce more and better evidence to determine the effect of pictorial warnings on cigarette packages on behavior change that can be useful for legislators and policy makers.
References
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