The broadening of Singapore’s smoking prohibition in 2013 to include the shared spaces of residential areas and various outdoor locations might have prevented as many as 20,000 heart attacks in individuals aged 65 and above. This finding comes from a pioneering local study that explored the health outcomes of extending smoking restrictions to outdoor environments.
Published in BMJ Global Health, a peer-reviewed open-access journal, the research was spearheaded by experts from the Duke-NUS Medical School. They discovered that the augmentation of the smoking ban correlated with a reduction in the monthly incidence of heart attacks, mainly benefiting the elderly and male populations.
Globally, exposure to second-hand smoke is linked to approximately 1.3 million deaths annually, with a significant number of these deaths due to heart attacks. Despite this, the positive health impacts of comprehensive smoke-free laws—adopted by 67 countries since 2003—are predominantly documented for indoor smoking prohibitions, leaving a gap in understanding regarding bans in residential and outdoor areas.
Dr Joel Aik, an Adjunct Assistant Professor in the Health Services & Systems Research Programme at Duke-NUS and the study’s senior author, highlighted the importance of smoke-free zones in communal areas of housing estates, where residents often gather. He emphasized that such bans minimize residents’ exposure to tobacco smoke, thereby lowering their heart attack risk.
To protect its citizens, Singapore expanded its smoke-free laws in 2013 to include all communal spaces in residential buildings—home to 80% of the population—as well as outdoor areas like covered walkways, overhead bridges, and the vicinity of bus stops. This initiative was extended in subsequent years to encompass reservoirs, residential parks, educational institutions, and more types of public transportation.
The researchers evaluated the impact of these legislative measures on heart attack occurrences by analyzing monthly data from the Singapore Myocardial Infarction Registry between January 2010 and December 2019. Over this decade, 133,868 heart attacks were recorded, with a significant proportion occurring among men and older adults.
Before the 2013 law expansion, the heart attack rate for those aged 65 and above was significantly higher than for younger individuals, with men experiencing nearly double the rate of women. Following the implementation of the law, there was a notable decline in heart attack rates, particularly among seniors and men, suggesting that these groups benefited most from the smoking ban.
The study estimated that the legislation may have prevented approximately 19,591 heart attacks in older adults and 4,748 in men. However, the impact of further legislative extensions on heart attack rates in later years was less pronounced, possibly due to advancements in diagnostic technology. Despite this, the consistent reduction in heart attack rates across different demographics following the 2017 law expansion indicates potential benefits, although further research is needed for confirmation.
Professor Patrick Tan, Senior Vice-Dean for Research at Duke-NUS, remarked on the study’s implications for policymakers, especially in Asia, where smoking remains a significant public health challenge. The research offers additional evidence to support the expansion of smoke-free laws as a means to mitigate the harmful effects of tobacco smoke exposure and reduce the burden of heart disease.
More information: Jamie S Y Ho et al, 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. DOI: 10.1136/bmjgh-2023-012339
Journal information: BMJ Global Health Provided by Duke-NUS Medical School
