How reactions to cigarette packet health warnings influence quitting: findings from the ITC Four-Country survey.

OBJECTIVES To examine prospectively the impact of health warnings on quitting activity. DESIGN Five waves (2002-06) of a cohort survey where reactions to health warnings at one survey wave are used to predict cessation activity at the next wave, controlling for country (proxy for warning differences) and other factors. These analyses were replicated on four wave-to-wave transitions. SETTING AND PARTICIPANTS Smokers from Australia, Canada, the United Kingdom and the United States. Samples were waves 1-2: n = 6525; waves 2-3: n = 5257; waves 3-4: n = 4439; and waves 4-5: n = 3993. MEASURES Warning salience, cognitive responses (thoughts of harm and of quitting), forgoing of cigarettes and avoidance of warnings were examined as predictors of quit attempts, and of quitting success among those who tried (1 month sustained abstinence), replicated across four wave-to-wave transitions. RESULTS All four responses to warnings were independently predictive of quitting activity in bivariate analyses. In multivariate analyses, both forgoing cigarettes and cognitive responses to the warnings predicted prospectively making quit attempts in all replications. However, avoiding warnings did not add predictive value consistently, and there was no consistent pattern for warning salience. There were no interactions by country. Some, but not all, the effects were mediated by quitting intentions. There were no consistent effects on quit success. CONCLUSIONS This study adds to the evidence that forgoing cigarettes as a result of noticing warnings and quit-related cognitive reactions to warnings are consistent prospective predictors of making quit attempts. This work strengthens the evidence base for governments to go beyond the Framework Convention on Tobacco Control to mandate health warnings on tobacco products that stimulate the highest possible levels of these reactions.