Differential Responses to Cigarette Package Labeling Alternatives Among Adults Who Smoke: Results From a Randomized Trial.

Introduction: Little experimental research has evaluated whether the effects of cigarette package inserts with efficacy messages and/or pictorial health warning labels (PHWLs) differ across key subgroups of adults who smoke.

Aims and methods: Adults who reported currently smoking (n = 367) were randomly assigned to one of four groups: Small text-only HWLs on pack sides (control); inserts with efficacy messages and small HWLs (inserts-only); PHWLs showing harms of smoking (PHWLs-only); both (inserts + PHWLs). Participants received a 14-day supply of cigarettes labeled to reflect their group. Every evening over 2 weeks, participants reported forgoing and stubbing out cigarettes before they finished smoking over the prior 24 hours, combined into a binary indicator of either behavior (eg, forgoing/stubbing). Separate mixed-effects logistic models were estimated to evaluate moderation of labeling group contrasts (ie, PHWLs vs not; inserts vs. not; inserts-only vs. inserts + PHWLs; PHWLs-only vs. inserts + PHWLs) by baseline covariates (self-efficacy to quit, intention to quit, education, health literacy, and time discounting), predicting day-level forgoing/stubbing.

Results: Education moderated PHWL effects, with PHWLs predicting more forgoing/stubbing only among those with low education (OR = 4.68, p < .001). Time discounting moderated insert effects, with inserts promoting forgoing/stubbing only among those with low time discounting (ie, lower impulsivity; OR = 4.35, p < .001).

Conclusions: Inserts with efficacy messages appear effective mostly among people with low time discounting, whereas PHWLs appear most effective among those with low education, suggesting their potential to address education-related disparities. Labeling strategies appeared equally effective across subgroups defined by self-efficacy to quit, quit intention, and health literacy. Combining inserts with PHWLs did not appear to mitigate moderation effects.

Implications: This randomized trial with adults who smoke suggests that cigarette packs with inserts describing cessation benefits and tips can promote cessation-related behaviors (ie, forgoing or stubbing out cigarettes) among those with low-time discounting (ie, low impulsivity). Alternative interventions may be needed for people with high-time discounting, as found in cessation trials. PHWLs appear most effective among those with low education, potentially addressing education-related disparities. No differential effects were found for those with different levels of self-efficacy to quit, quit intentions, or health literacy. Combining inserts and PHWLs may not be more effective than either alone.