Abridged risk information: Effects of warning labels on snus packages

Abstract

<i>Background</i> - We screened the sparse literature on how health warnings on snus products affect risk perception and use intentions, and contributed with two experimental studies on the topic.<p>

<p><i> Methods</i> - First, we examined previous studies on health warnings on smokeless tobacco in a systematic review, studied the manipulations in exposure studies, and systematized the outcome measures and main results. Next, we examined how textual health warnings applied in the European Union, and finally warnings comparing risks from snus and cigarettes, affected risk perception and intentions to use. The studies were experiments, with participants randomized to a warning or control condition, and risk perception and intentions to use measured pre and post warning exposure.<p>

<p><i>Results</i> - Of 808 articles, 12 were included in the systematic review. All studied cognitive outcomes, six included outcomes related to behavior. Graphic warnings had stronger effects on some measures, for example on attention and thoughts about health risks. Removing “can” from the warning “This product (can) damages your health” increased long-term risk perception, although not when followed up in a pre-post study. The same warning kept perceptions of risk stable, while a comparative warning reduced perceived risks from snus and adjusted its perceived relative risk to smoking closer to expert opinions. Intention to use snus did not change.<p>

<p><i>Discussion</i> - The few studies on effects from smokeless tobacco warnings mimic the effects from cigarette warnings: graphic elements have a stronger effect on some measures. Research about comparative warnings is very sparse. Minor verbal changes in warning texts do not seem to have reliable effects on risk perception, but changing the content to comparative information can have a stronger impact, especially when using concrete information such as percentages.<p>

<p><i>Conclusion</i> - Text-only warnings may be less effective than graphic warnings, and comparative information may affect perceptions of risk differently than non-comparative.