About the data
The limited availability of data on health status is a
many developing countries most new infections
• Prevalence of smoking is the adjusted and age-
major constraint in assessing the health situation in
occur in young adults, with young women especially
standardized prevalence estimate of smoking among
developing countries. Surveillance data are lacking
adults. The age range varies but in most countries is
for many major public health concerns. Estimates
Data on HIV are from the Joint United Nations
18 and older or 15 and older. • Incidence of tuber-
of prevalence and incidence are available for some
Programme on HIV/AIDS (UNAIDS) Global Report:
culosis is the number of new and relapse cases of
diseases but are often unreliable and incomplete.
UNAIDS Report Global AIDS Epidemic 2010. Changes
tuberculosis (all types) per 100,000 people. • Preva-
National health authorities differ widely in capacity
in procedures and assumptions for estimating the
lence of diabetes refers to the percentage of people
and willingness to collect or report information. To
data and better coordination with countries have
ages 20–79 who have type 1 or type 2 diabetes.
compensate for this and improve reliability and inter-
resulted in improved estimates of HIV and AIDS. For
• Prevalence of HIV is the percentage of people who
national comparability, the World Health Organiza-
example, improved software was used to model the
are infected with HIV. Total and youth rates are per-
tion (WHO) prepares estimates in accordance with
course of HIV epidemics and their impacts, making
centages of the relevant age group. Female rate is as
epidemiological models and statistical standards.
full use of information on HIV prevalence trends from
a percentage of the total population living with HIV.
Smoking is the most common form of tobacco use
surveillance data as well as survey data. The soft-
• Condom use is the percentage of the population
and the prevalence of smoking is therefore a good
ware explicitly includes the effect of antiretroviral
ages 15–24 who used a condom at last intercourse
measure of the tobacco epidemic (Corrao and others
therapy (ART) when calculating HIV incidence and
in the last 12 months.
2000). Tobacco use causes heart and other vascular
models reducted infectivity among people receiv-
diseases and cancers of the lung and other organs.
ing ART, which is having an increasing impact on
Given the long delay between starting to smoke and
HIV prevalence, with HIV-positive people living lon-
the onset of disease, the health impact of smoking
ger lives. The software also allows for changes in
in developing countries will increase rapidly only in
urbanization over time—important because preva-
the next few decades. Because the data present a
lence is higher in urban areas and because many
one-time estimate, with no information on intensity
countries have seen rapid urbanization over the past
or duration of smoking, and because the definition of
adult varies, the data should be used with caution.
The estimates include plausible bounds, not shown
Tuberculosis is one of the main causes of adult
in the table, which reflect the certainty associated
deaths from a single infectious agent in develop-
with each of the estimates. The bounds are avail-
ing countries. In developed countries tuberculosis
able at http://data.worldbank.org or from the original
has reemerged largely as a result of cases among
immigrants. Since tuberculosis incidence cannot
Data on condom use are from household surveys
be directly measured, estimates are obtained by
and refer to condom use at last intercourse. How-
eliciting expert opinion or are derived from mea-
ever, condoms are not as effective at preventing the
surements of prevalence or mortality. These esti-
transmission of HIV unless used consistently. Some
mates include uncertainty intervals, which are not
surveys have asked directly about consistent use,
shown in the table, which are available at http://
but the question is subject to recall and other biases.
data.worldbank.org or from the original source.
Caution should be used in interpreting the data.
Diabetes, an important cause of ill health and a
For indicators from household surveys, the year in
risk factor for other diseases in developed countries,
the table refers to the survey year. For more informa-
is spreading rapidly in developing countries. Highest
tion, consult the original sources.
among the elderly, prevalence rates are rising among younger and productive populations in developing
countries. Economic development has led to the
Data on smoking are from the WHO’s Report on
spread of Western lifestyles and diet to develop-
the Global Tobacco Epidemic 2009: Implementing
ing countries, resulting in a substantial increase in
Smoke-Free Environments. Data on tuberculosis
diabetes. Without effective prevention and control
are from the WHO’s Global Tuberculosis Control
programs, diabetes will likely continue to increase.
Report 2010. Data on diabetes are from the Inter-
Data are estimated based on sample surveys.
national Diabetes Federation’s Diabetes Atlas,
Adult HIV prevalence rates reflect the rate of HIV
3rd edition. Data on prevalence of HIV are from
infection in each country’s population. Low national
UNAIDS’s Global Report: UNAIDS Report on the
prevalence rates can be misleading, however. They
Global AIDS Epidemic 2010. Data on condom use
often disguise epidemics that are initially concen-
are from Demographic and Health Surveys by
trated in certain localities or population groups and
threaten to spill over into the wider population. In
2011 World Development Indicators
Health risk factors and future challenges
Published on Apr 4, 2011
Looking for accurate, up-to-date data on development issues? 'World Development Indicators' is the World Bank's premier annual compilation o...