摘要：Objectives. We examined the rate of acute myocardial infarction (AMI) deaths in Massachusetts before and after the implementation of a comprehensive smoke-free workplace law in July 2004. Methods. We used Poisson regression models to examine the impact of the state law in cities and towns with and without previous local smoking bans and the effect of the local laws for the period of 1999 through 2006. Results. The AMI mortality rate decreased by 7.4% (95% confidence interval [CI] = 3.3%, 11.4%) after implementation of the state law. The state ban had an impact in cities and towns with no prior local smoking ban (9.2% decrease; P < .001) but not cities and towns with a prior local smoking ban. However, there was a nonsignificant 4.9% (95% CI = −5.0%, 13.9%) decrease associated with the local smoking ban that preceded the effect of the state ban. The effect of the state ban was modest (−1.6%) in the first 12 months after implementation but much larger after the first 12 months (−18.6%; P < .001). Conclusions. Comprehensive statewide smoke-free workplace laws in Massachusetts were associated with an estimated 270 fewer AMI deaths per year. These results add to the evidence suggesting that smoke-free air laws are associated with lower rates of AMI. Comprehensive smoking bans prohibit smoking in workplaces, including public and private worksites, restaurants, and bars. Studies have shown that comprehensive smoking bans reduce exposure to environmental tobacco smoke, whereas smoking restrictions, which permit designated smoking areas or provide separately ventilated sections, are not effective at preventing or eliminating exposure to environmental tobacco smoke. 1 In addition to reducing exposure to environmental tobacco smoke, comprehensive smoking bans may change social norms regarding the acceptability of smoking in a community, resulting in fewer people smoking in public places. 1 Comprehensive smoking bans have been shown to reduce smoking prevalence by 3.8% (95% confidence interval [CI] = 2.8%, 4.7%) and to reduce the number of cigarettes smoked per smoker per day by 3.1 (95% CI = 2.4, 3.8). 2 Both cigarette smoking and exposure to environmental tobacco smoke increase the risk of coronary heart disease (CHD). 1 It is hypothesized that a decrease in these exposures as a result of a comprehensive smoking ban would result in reductions in CHD. The association between comprehensive smoking bans and acute myocardial infarction (AMI) hospital admissions was examined previously in the United States and Europe. Several meta-analyses have been conducted that pooled the results of these studies and found that comprehensive smoking bans were associated with a 17% to 19% lower AMI hospital admission rate. 3 – 5 The first comprehensive workplace smoking ban in Massachusetts was implemented in 1994 in the town of Amherst. 6 Individual cities and towns enacted comprehensive smoking bans over the next decade. In 2003, Boston, Cambridge, and Somerville implemented comprehensive smoking bans. All residents of Massachusetts were covered by the state comprehensive smoking ban in July 2004, which banned smoking in all workplaces, including restaurants and bars. 7 The experience in Massachusetts, in which local laws introduced comprehensive workplace smoking bans at various times, offers the opportunity to assess the impact of the local and statewide laws both separately and jointly. We examined the AMI mortality rate before and after the Massachusetts smoke-free air law in cities and towns with and without prior local comprehensive smoking bans. We also examined the impact of the local smoking bans before the statewide smoke-free law took effect.
