The Smoke Clears in Scotland

When we last considered claims about the impact of Scotland's smoking ban, an alleged 17 percent drop in hospital admissions for heart attacks (a claim reported in the New England Journal of Medicine and widely repeated by the press) turned out to be more like 8 percent in the year after the ban took effect. A drop of this size is consistent with the pre-existing downward trend in heart attacks. Now data for the second year after the ban was imposed show an increase in heart attack admissions roughly equal to the previous year's decline. Christopher Snowden observes:

If the 2006-07 decline had really been the result of the smoke-free legislation, it would be expected for rates to remain low in subsequent years. The fact that Scottish hospitals have seen an unusually sharp rise—despite the smoking ban being rigorously enforced—suggests that whatever lay behind the 2006-07 dip, it was not the smoking ban.

Hospital data from England and Wales has failed to show a significant reduction in incidence of acute coronary syndrome since going smoke-free in 2007. This new evidence from Scotland casts serious doubts on the theory that smoking bans have a measureable impact on incidence of acute coronary syndrome.

As I noted in connection with smoking bans in Massachusetts, such laws, to the extent that they encourage smokers to quit and deter others from picking up the habit, can be expected to reduce heart disease over the long term, even if secondhand smoke has no effect on the cardiovascular health of bystanders. But the sharp, immediate reductions reported in some jurisdictions with smoking bans (beginning with Helena, Montana, in 2003) are not biologically plausible and are almost certainly due to random variation or pre-existing trends.

Michael Siegel challenges anti-smoking groups that seized on the NEJM report as evidence of the benefits from smoking bans to acknowledge the more recent data. He cites misleading statements about the Scottish ban from 19 groups and offers a $200 prize to the one that corrects the record first. "I am not going to lose sleep worrying about my $200," he says, "because I am sure that no anti-smoking groups will respond appropriately."