Smoking bans reduce heart attack admissions

Bans on smoking substantially reduce hospital admissions for heart attacks, research has shown.

On the first anniversary of the ban on public smoking in England, a report shows that smoke-free laws worldwide reduce admissions by almost one fifth (Preventive Medicine 2008 Jun 18; doi: 10.1016/j.ypmed.2008.06.007).

This meta-analysis of published studies shows that the effects were immediate. "The fact that many studies from so many locations around the world provide consistent findings of a substantial drop in acute myocardial infarction associated with the implementation of smoke-free laws increases the confidence that . . . smoke-free policies have immediate and substantial benefits in terms of reducing acute myocardial infarctions," says the author, Stanton Glantz, professor of medicine at the University of California.

The analysis is based on eight studies published since 2004, when the first report of such a drop was reported for the town of Helena , Montana .

The results of the analysis show a pooled estimate of an immediate 19% (95% confidence interval 14% to 24%) reduction to admission rates associated with the laws.

The report says that the fact that the studies from Italy and Ireland showed smaller drops in admissions than in US locations may reflect lower levels of compliance with the law. It says that in Italy and Ireland implementation of the law was associated with a reduction in levels of secondhand smoke exposure of 64% and 69%, compared with an 84% reduction in the United States .

The analysis does not include two studies for which confidence intervals are not available-a small study of Monroe County , Indiana , which found a significant drop in admissions, and a study of Scotland presented at a conference, which reported a 17% drop but which has not yet been published.

The smoke-free law in England, introduced on 1 July last year to make virtually all enclosed public places and workplaces smokefree, has helped record numbers of smokers to quit and will help prevent an estimated 40 000 deaths in the next 10 years, according to the smoking toolkit study, funded by Cancer Research UK, McNeil, Pfizer, and GlaxoSmithKline, and presented at the UK National Smoking Cessation Conference this week.

The decline in smoking prevalence for the nine months before the ban was 1.6% compared with 5.5% in the nine months after. Based on these findings, the researchers estimate that at least 400 000 people quit smoking as a result of the ban.

Robert West, Cancer Research UK 's director of tobacco studies at the health behaviour research centre at University College London, who carried out the study, said, "These figures show the largest fall in the number of smokers on record. I never expected such a dramatic impact and of course there are no guarantees that smoking rates will not climb back up again."

The study was based on interviews with more than 32 000 people in England over the nine months before and nine months after the law took effect.

Cite this as: BMJ 2008;337:a597

 

 Meta-analysis of the effects of smokefree laws on acute myocardial infarction: An update

 Preventive Medicine
Article in Press, Accepted Manuscript

Stanton A. Glantz^a