The hazards of smoking and the benefits of cessation: a critical summation of the epidemiological evidence in high-income countries

Abstract

In high-income countries, the biggest cause of premature death, defined as death before 70 years, is smoking of manufactured cigarettes. Smoking-related disease was responsible for about 41 million deaths in the United States, United Kingdom and Canada, cumulatively, from 1960 to 2020. Every million cigarettes smoked leads to one death in the US and Canada, but slightly more than one death in the UK. The 21^st century hazards reveal that smokers who start smoking early in adult life and do not quit lose a decade of life expectancy versus non-smokers. Cessation, particularly before age 40 years, yields large reductions in mortality risk. Up to two-thirds of deaths among smokers are avoidable at non-smoking death rates, and former smokers have about only a quarter of the excess risk of death compared to current smokers. The gap between scientific and popular understanding of smoking hazards is surprisingly large.

Keywords: epidemiology; global health; hazards; high-income countries; mortality; smoking; tobacco.

Figure 1.. Trends in per capita consumption in Canada, US, UK in cigarettes per adult per year.

Note. Data from Forey et al. (2016), International smoking statistics.

Figure 2.. Prevalence (%) of adult males (right panel), and females (left panel), usually 15 to 18 years or older that smoke by sex in US, UK and Canada.

Note. Data from National Center for Health Statistics, 2008, 1965–2012 National Health Interview Survey (NHIS); Office for National Statistics, 2018, Adult Smoking habits in Great Britain; and Reid et al., 2017, Tobacco Use in Canada: Patterns and Trends, 2017 Edition.

Figure 3.. Survival by smoking among US insured adults.

Figure 4.. Trends in per capita cigarette consumption and age-standardized lung cancer death rates in the US.

Adapted from American Cancer Society (2013).

Figure 5.. Trends in age-specific lung cancer death rates among men and women at ages 35–39, 55–59 and 75–79 in selected countries.

Figure 6.. Lung cancer death rates by sex by study period.

Adapted from U.S. Department of Health and Human Services (2014).

Figure 7.. Number of cigarettes (from 1955 to 1985) per death with a 20 year lag in US, UK, and Canada (from 1975 to 2005).

Note. Author’s calculations.

Figure 8.. Survival differences between smokers and non-smokers, adjusting for various factors.

Adapted from Jha and Peto (2014), p. 62.

Figure 9.. USSGR 2014 estimation of anatomic sites and cancers linked to smoking.

Adapted from U.S. Department of Health and Human Services (2014).

Figure 10.. Former and current smoking prevalence, US (2017), UK (2017), and Canada (2014) by sex and age group.

Note. Data from National Center for Health Statistics, 2017, NHIS, Office for National Statistics, 2017, Adult Smoking habits in Great Britain; Statistics Canada, 2016, Canadian Community Health Survey.

Figure 11.. Relative risks for all-cause mortality and cancer of the lung, by age of quitting, among UK women.

Adapted from Pirie et al. (2013), p. 138.

Figure 12.. Life expectancy: loss of 3 years with moderate obesity and 10 years with smoking.

Note: 2 kg/m² extra BMI (if overweight) or 10% smoking prevalence shortens life by ~1 year. Adapted from Peto et al. (2010), p. 856.