In high-income nations, smoking remains the leading cause of premature death, with manufactured cigarettes contributing significantly to mortality rates. According to research in the United States, United Kingdom, and Canada, smoking-related diseases have accounted for approximately 41 million deaths.
Shockingly, every million cigarettes smoked leads to at least one death in the US and Canada, and slightly more in the UK. Moreover, smokers who initiate the habit early in adult life and continue without cessation sacrifice about a decade of their life expectancy compared to non-smokers.
Perhaps in response to these grim statistics, or perhaps coincidentally, there has been a notable increase in smoking cessation over the past decade. Either way, this trend has opened avenues for researchers to explore whether quitting smoking effectively reduces mortality rates associated with smoking-attributable diseases.
Therefore, Dr. Eo Rin Cho from the Centre for Global Health Research, Unity Health, and Dalla Lana School of Public Health, Toronto and colleagues from UiT-The Arctic University of Norway set out to research the potential benefits of smoking cessation across various demographics including age, sex, and duration since quitting, mainly in high-income countries. Their study was published in the New England Journal of Medicine Evidence.
People from the US, UK, Canada, and Norway were assessed between the years 1974 to 2018. In total, 1.48 million adults were included in the study analysis, with an average follow-up period of 15 years.
Of these participants, 122,697 individuals died during the observation period. Participants were categorized into three groups: current, former, and never smokers. The researchers then calculated smoking trends and hazard ratios of mortality due to smoking-attributable diseases.
Heavy smoking (defined as more than 20 cigarettes a day) was more prevalent in men (32%) than women (20%), yet women exhibited slightly higher hazard ratios for overall mortality associated with heavy smoking.
The hazard ratios for overall mortality were notably elevated among current smokers when compared to never smokers. Specifically, the hazard ratio was 2.8 for women and 2.7 for men. This indicates that current smokers were nearly three times as likely to die due to smoking-attributable diseases compared to those who had never smoked, regardless of gender.
Notably, across all age groups, cessation of smoking for 10 years or more resulted in survival rates comparable to those of never smokers. However, quitting smoking —particularly before the age of 40 — was associated with a decreased risk of mortality.
In conclusion, this research provides compelling evidence supporting the link between smoking cessation and lowering mortality rates due to smoking-related diseases. It also emphasizes the necessity of targeted public health initiatives designed to encourage and facilitate smoking cessation among diverse demographic groups.
