Impact of indoor smoking bans on hospitalizations due to acute miocardial infarction in Uruguay

Abstract

Introduction: exposure to environmental tobacco smoke increases the risk for infarction in 31% among non-smokers. A decrease in hospital admission due to acute myocardial infarction was noticed in developed countries when indoor smoking was banned. The present study analyzed the impact of smoking bans on acute myocardial infarction in Uruguay, the first tobacco- smoke-free-country in the Americas.
Method: we conducted an ecological study that compared hospital admissions for infarction in the 24 months prior to March 2006 to admissions during the 24 months subsequent to that date (date when the anti-smoking regulation was passed, banning indoor public spaces). We retrospectively analyzed the medical records of patients residing in the country whose main diagnosis for admission was myocardial infarction. The statistic analysis was made by using the chi square test.
Results: 7,949 patients were admitted in the 37 participating institutions (66,4 ± 12,6 years old, 35,1% women), 4,346 were admitted over the two year period prior to the new measures, and 3,603 during the two-year period subsequent to the prohibition, what implied a 17.1% drop. The younger the patients, the greater the drop: <45years old: 38,5%; 45 to 64 years old: 14,8%; > 65 years old: 16,9%, p < 0,05. Admissions decreased by 24.2% on Fridays and Saturdays, and 14.3% from Sundays to Thursdays (p < 0,05). Decrease was 22.0% in private institutions and 6.3% in public institutions, p < 0,05.
Conclusions: Indoor smoking bans were associated to a decrease in hospital admission for acute myocardial infarction in our country, being this effect particularly important in the younger people. The benefit of this new legislation was more important on Fridays and Saturday and lower in those patients seen in the public sector.