Aims: We used the hospital discharge records of Piedmont region (northern Italy) to evaluate whether a national law banning smoking in public resulted in a short-term reduction in hospital admissions for acute myocardial infarction (AMI).
Methods and results: Rates of admission for AMI before the ban (October-December 2004) and during the ban (February-June 2005) were analysed. Each period was compared with the corresponding period 12 months before. Among persons aged under 60, the number of admissions for AMI decreased significantly after the introduction of the ban: from 922 cases in February-June 2004 to 832 cases in February-June 2005 (sex- and age-adjusted rate ratio, 0.89; 95% confidence interval, 0.81-0.98). No decrease was seen before the ban. No effect was found among persons aged at least 60. We estimated that the observed reduction in active smoking after the introduction of the ban could account for a 0.7% decrease in admissions for AMI during the study period, suggesting that most of the observed effect (11%) might be due to the reduction of passive smoking.
Conclusion: Our study, based on a population of about 4 million inhabitants, suggests that smoke-free policies may result in a short-term reduction in admissions for AMI.