Abstract
Importance
Tobacco is a leading global disease risk factor. Understanding national trends in prevalence and consumption is critical for prioritizing action and evaluating tobacco control progress.
Objective
To estimate the prevalence of daily smoking by age and sex and the number of cigarettes per smoker per day for 187 countries from 1980 to 2012.
Design
Nationally representative sources that measured tobacco use (n = 2102 country-years of data) were systematically identified. Survey data that did not report daily tobacco smoking were adjusted using the average relationship between different definitions. Age-sex-country-year observations (n = 38 315) were synthesized using spatial-temporal gaussian process regression to model prevalence estimates by age, sex, country, and year. Data on consumption of cigarettes were used to generate estimates of cigarettes per smoker per day.
Main Outcomes and Measures
Modeled age-standardized prevalence of daily tobacco smoking by age, sex, country, and year; cigarettes per smoker per day by country and year.
Results Global modeled age-standardized prevalence of daily tobacco smoking in the population older than 15 years decreased from 41.2% (95% uncertainty interval [UI], 40.0%-42.6%) in 1980 to 31.1% (95% UI, 30.2%-32.0%; P < .001) in 2012 for men and from 10.6% (95% UI, 10.2%-11.1%) to 6.2% (95% UI, 6.0%-6.4%; P < .001) for women. Global modeled prevalence declined at a faster rate from 1996 to 2006 (mean annualized rate of decline, 1.7%; 95% UI, 1.5%-1.9%) compared with the subsequent period (mean annualized rate of decline, 0.9%; 95% UI, 0.5%-1.3%; P = .003). Despite the decline in modeled prevalence, the number of daily smokers increased from 721 million (95% UI, 700 million–742 million) in 1980 to 967 million (95% UI, 944 million–989 million; P < .001) in 2012. Modeled prevalence rates exhibited substantial variation across age, sex, and countries, with rates below 5% for women in some African countries to more than 55% for men in Timor-Leste and Indonesia. The number of cigarettes per smoker per day also varied widely across countries and was not correlated with modeled prevalence.
Conclusions and Relevance
Since 1980, large reductions in the estimated prevalence of daily smoking were observed at the global level for both men and women, but because of population growth, the number of smokers increased significantly. As tobacco remains a threat to the health of the world’s population, intensified efforts to control its use are needed.
The year 2014 marks the 50th anniversary of the release of the first US surgeon general’s report1 on the health effects of smoking. The report’s conclusions led to further research on both the consequences of tobacco use and potential interventions to reduce tobacco prevalence and cigarette consumption. A wide range of effective interventions are available including increasing prices and bans on advertising, promotion, sales to minors, and smoking in public places.2- 5 The adoption of the Framework Convention on Tobacco Control (FCTC) in 2003 and its subsequent ratification by 177 countries reflects growing global efforts to control tobacco.6,7 Despite such efforts, tobacco continues to adversely influence global health patterns, leading to 5.7 million deaths, 6.9% of years of life lost, and 5.5% of disability-adjusted life-years (DALYs) in 2010.8,9 Given the importance of tobacco as a risk to health, monitoring the distribution and intensity of tobacco use is critical for identifying priority areas for action and evaluating progress.
Early efforts to estimate smoking prevalence10,11 were based on limited data for many developing countries. Investments in multicountry survey programs have subsequently substantially expanded the primary data available for monitoring. The most recent cross-sectional estimates of smoking prevalence were for 2011.7 Efforts to track cigarette consumption per capita have been less systematic over time, with results that differ substantially by source.12- 14The Tobacco Atlas15 has greatly facilitated the policy use of these data by assembling them in 1 location.
Despite improvements in data availability, information on trends has not been synthesized in a systematic and consistent way. This article presents modeled estimates of levels and trends in the prevalence of smoking by age and sex and consumption of cigarettes for 187 countries from 1980 to 2012.
