Can the effects of fear arousing pictorial warning labels on cigarette packs be enhanced with inserts containing efficacy messages? Results from a two-week randomized trial

Theoretical Background and research questions/hypothesis: Studies have consistently demonstrated the effectiveness of pictorial health warning labels on the outside of packs for increasing understanding of risks and discouraging smoking; however, much less is known about the effects of inserts (i.e., small leaflets) inside of cigarette packs. Only Canada has implemented inserts, which contain rotating efficacy messages with tips to quit and descriptions of cessation benefits. The current randomized controlled trial (RCT) with adult smokers investigates the independent and potentially synergistic effects of efficacy inserts and pictorial health warning labels (PHWLs) on cigarette packages.

Methods: In our 2x2 RCT, adult smokers who smoked at least 100 cigarettes in their lifetime and 10 per day in the previous month were randomized to one of four conditions: 1) large pictorial health warning labels (HWLs; n=90), 2) inserts with efficacy messages and small text-only HWLs (n=84), 3) large PHWLs and inserts with efficacy messages (n=87), or 4) the control group with small text-only HWLs (n=98) and given a 2-week supply of their preferred brand variety, with packs modified to reflect their experimental condition. At the end of the trial, participants reported their responses to pack labels over the study period, including noticing, reading, and discussing labels, forgoing any cigarettes, thinking about smoking risks and the benefits of quitting, motivation to quit, and labels’ assistance. Ordinal logistic regression models were used to analyze the relationships between these outcomes and experimental conditions (vs. control). We also examined the potential mediating and moderating effects of engagement with labels (I.e., noticing and reading) on the other responses to labels.

Results: Across all outcomes, those in the inserts + PHWL condition had stronger label responses than the control group (ORs: 2.34-6.89, p-values <0.001), and for each outcome, the association was stronger than for those in the insert-only group (ORs: 1.39-3.53, p-values:<0.001-0.24) or the PHWL only group (ORs: 1.27-2.70 p-values:<0.001-0.50). Results from mediation analyses indicated that the entire effect of the experimental condition on all outcomes is explained by the influence of label engagement (I.e., noticing and reading).

Conclusions: Our study indicated that combining inserts with efficacy messages and prominent PHWLs was more effective in promoting desirable responses to cigarette labeling than either labeling strategy alone. This is consistent with behavior change theories that emphasize the need for efficacy messages to enhance the effectiveness of fear arousing messages, like those on PHWLs Countries should consider adopting this complementary strategy for public health communication to promote smoking cessation.

Implications for research and/or practice: This study highlights the importance of combining PHWLs that have fear-arousing content with pack inserts containing efficacy messages, providing a foundation for further research on ways to enhance the impact of tobacco product labeling. However, further research with longer follow-up periods is needed to evaluate this strategy’s impact on smoking cessation. Approximately half of all countries have implemented PHWLs, and inserts may enhance their impact. In the US, inserts present a legally viable strategy that may overcome First Amendment issues that the tobacco industry has used to block PHWL implementation for over a decade.