Ten-Year Follow-Up of the Impact of Scottish Smoke-Free Legislation on Acute Myocardial Infarction.

Abstract

Worldwide, 181 countries have ratified the World Health Organization’s Framework Convention on Tobacco Control and become Parties to the convention,1 and 1.5 billion people in 55 countries are now protected by comprehensive smoke-free legislation.2 Smoke-free legislation has been associated with many health benefits, but the most extensively researched has been myocardial infarction. Thirty-one studies, covering legislation in 47 jurisdictions, produced a pooled relative risk reduction of 12%.3 Many used simple before and after comparisons and most had follow-up to only 1 to 2 years after legislation. In Scotland, the Smoking, Health and Social Care Act prohibited smoking in all enclosed public and workplaces from March 2006. There was a 17% reduction in myocardial infarctions in the year after implementation compared with a 4% decline in England where legislation had not been introduced.4 The primary aim was to protect nonsmokers from the harmful effects of secondhand smoke. However, the legislation was associated with a short-term increase in quit attempts and temporary reduction in smoking prevalence.5 Hence, in the year after legislation, myocardial infarctions fell among current, as well as nonsmokers,4 and it is not known whether the overall reduction in myocardial infarctions has been maintained long-term. This study uses interrupted time-series analysis to investigate whether myocardial infarction incidence over the 10 years after Scottish legislation differed from the underlying trend before legislation.