A study published in the open-access journal BMJ Global Health suggests that extending the smoking ban to communal areas of residential blocks and other outdoor spaces in Singapore in 2013 may have prevented up to 20,000 heart attacks among those aged 65 and older. The extension of the smoking ban in Singapore was associated with a monthly decrease in the rate of heart attacks, with older individuals and men benefiting the most from this public health measure.Â
Second-hand smoke exposure is a significant global health concern, responsible for 1.3 million annual deaths, many of which result from heart attacks. Despite the known dangers of second-hand smoke, evidence of the health benefits of comprehensive smoke-free laws has primarily focused on indoor smoking bans rather than extending restrictions to housing estates and outdoor spaces.Â
In 2013, Singapore took a significant step by extending smoke-free legislation to all communal areas of residential blocks, covering approximately 80% of the population. This legislation also included outdoor spaces such as covered linkways, overhead bridges, and areas within 5 meters of bus stops. Subsequently, in 2016, the ban was further extended to include all parks, and in 2017, it applied to all educational institutions, buses, and taxis.Â
To assess the impact of these legislative changes on heart attack rates, the researchers conducted an analysis using data from the Singapore Myocardial Infarction Registry. They collected monthly reports from January 2010 through December 2019, during which 133,868 heart attacks were reported. Of these cases, 66% occurred among men, and 60% occurred in individuals aged 65 and older.Â
Before the 2013 ban extension, the prevalence of heart attacks among those aged 65 and older was approximately ten times higher than among those under 65. The rate of heart attack cases was also nearly double among men compared to women. Before the ban extension, the overall number of heart attacks increased at a rate of 0.9 per million people every month. However, after the extension, this rate fell to 0.6 per million, suggesting that an estimated 2,097 additional heart attacks might have occurred without the ban.Â
Older individuals and men experienced the most significant benefits from the extended ban. Among those aged 65 and older, the monthly decrease in heart attack rates was nearly 15 times greater than in younger individuals, with rates of 5.9 per million versus 0.4 per million. These findings suggest that an additional 19,591 heart attacks might have occurred in those aged 65 and older, compared to 1,325 in those under 65, had the legislation not been enacted. The ban also potentially averted 4,748 cases in men.Â
Public smoke-free laws are generally expected to reduce environmental smoke exposure in public spaces, theoretically lowering the risk of smoke-induced heart attack cases. The researchers suggest that the aging population in Singapore and the introduction of a new blood test for improved heart attack diagnosis might explain these figures.Â
This study provides evidence supporting the expansion of smoke-free laws to reduce the adverse health consequences of population exposure to tobacco smoke. The extension of the smoking ban in Singapore appears to have been effective, particularly among older individuals and men, in reducing the incidence of heart attacks in the community. Â
Reference Â
Association between the extension of smoke-free legislation and incident acute myocardial infarctions in Singapore from 2010 to 2019: an interrupted time-series analysis, BMJ Global Health (2023). DOI: 10.1136/bmjgh-2023-012339Â
