Prevalence of current tobacco use among adults aged ≥ 15 years (percentage)
Rationale for use
The prevalence of current tobacco smoking among adults is an important measure of the health and economic burden of tobacco, and provides a baseline for evaluating the effectiveness of tobacco control programmes over time. While a more general measure of tobacco use (including both smoked and smokeless products) would be ideal, data limitations restrict the present indicator to smoked tobacco. Occasional tobacco smoking constitutes a significant risk factor for tobacco-related diseases and is therefore included along with daily tobacco smoking.
Definition
The prevalence of current tobacco smoking (including cigarettes, cigars, pipes or any other smoked tobacco products). “Current smoking” includes both daily and non-daily or occasional smoking.
Associated terms
The definition of “smoker”, age ranges and age groups, representativeness and survey years varied across studies, so crude prevalences are not comparable.
Data sources
The WHO Global InfoBase collects all country-level data on important noncommunicable disease risk factors for all WHO Member States. It acts as a repository for all survey information relevant to eight risk factors, including tobacco use. Data are taken from a variety of sources, including published peer-reviewed journal articles, government reports and unpublished surveys provided directly by study authors.
Methods of estimation
Age standardized current tobacco prevalence estimates were obtained using crude data from individual surveys contained in the WHO Global InfoBase. Adjustments were made to obtain comparable estimates across countries.
Data were included in the estimation process if they came from surveys that:
- provided country survey summary data for one or more of four tobacco use definitions: daily smoker, current smoker, daily cigarette smoker, or current cigarette smoker;
- included randomly selected participants who were representative of a general population;
- presented prevalence values by age and sex; or
- surveyed the adult population aged 15 years and older.
Summary data were taken from all data sources, and analysis of tobacco use prevalence data was performed according to the following three main steps.
- Exploratory data analysis techniques were used to assess the general shape of the age association with prevalence and the relationships between the preferred definitions of tobacco use, and to check for data errors.
- Models were fitted to the country reported data and country-level estimates were made.
- Regional and subregional estimates were obtained by pooling across country-level estimates using the United Nations Statistics Division regional and subregional designations.
To allow comparability between countries, adjustments were made to account for differences in definitions of smokers, urban–rural representativeness, survey year and trends. These adjusted estimates (by definition of smoker, urban–rural relationship and survey year) were age-standardized using the WHO standard population. Prevalences were reported representing estimates for 2005. The adjustment of country-reported survey data was limited by the availability and quality of the country survey data.
Disaggregation
Age-standardized current smoker prevalence estimates are shown by country and gender, for the population aged 15 years and older.
Database
Comments
Developing standard methods for adjusting and reporting the prevalence of tobacco use represents our best effort for developing a baseline with which to compare future prevalence estimates of tobacco use. The ideal would be to have national government agreement on a standard framework for collecting survey data on chronic disease risk factors, including tobacco use, within a common timeframe. As this may take a little time, these estimates are intended to be the baseline for tobacco control efforts worldwide.