A study that compared cigarette warning labels from four countries concluded that those using pictorial images were more effective than text-based health messages, the BBC reported Feb. 6.

The study of labels used in the U.S., Canada, the U.K., and Australia also found that text warnings that are large and regularly updated are noticed more than smaller, static messages. About 15,000 smokers were involved in the study.

In Canada, which uses graphic images like a photo of a drooping cigarette to drive home the link between smoking and impotence, 60 percent of smokers said they noticed the warnings. In Australia, which requires text warnings to cover almost a third of cigarette packs, 52 percent of smokers noticed the warnings. But only 30 percent of U.S. smokers noticed the smaller Surgeon General's warnings on cigarette packs required since 1984.

About 15 percent of Canadian smokers said the warnings had deterred them from lighting up. "This study suggests that more prominent health warnings are associated with greater levels of awareness and perceived effectiveness among smokers," said researcher David Hammond.

The study was slated to be published in the March 2007 issue of the American Journal of Preventive Medicine.