Intro
In 1993 the World Bank, in collaboration with the World Health Organization (WHO) and the Harvard School of Public Health, sponsored a study to assess the global burden of disease in 1990 ( Murray, Lopez, and Jamison 1994 ; World Bank 1993 ). As well as generating the first comprehensive and consistent set of estimates of mortality and morbidity by age, sex, and region for the world, the Global Burden of Disease (GBD) study also introduced a new metric, the disability-adjusted life year (DALY), to quantify the burden of disease ( Murray and Lopez 1996c , 1996d ). The DALY is a summary measure of population health that combines years of life lost from premature death and years of life lived in less than full health and is described in more detail later. Thus, burden of disease analysis provides a unique perspective on health that integrates fatal and nonfatal outcomes, yet allows the two classes of outcomes to be examined separately as well.
The original (1990) GBD study analyzed and synthesized a large volume of data on population health to produce comprehensive and comparable information on the causes of loss of health globally and regionally, including low- and middle-income countries with considerable limitations in data availability and comparability. In addition, the GBD study made estimates even for diseases and conditions for which data were limited and involved considerable uncertainty to ensure that causes of the disease burden for which information was sparse were not implicitly considered to impose no burden and hence be ignored by health policy makers ( Murray, Mathers, and Salomon 2003 ).
Under the leadership of Chris Murray, WHO's executive director of the Evidence and Information for Policy Cluster from 1998 to 2003, WHO undertook a new assessment of the global burden of disease for 2000 to 2002, with consecutive revisions and updates published annually in WHO's world health reports. Version 1 estimates for 2000 were published in the World Health Report 2001 ( WHO 2001d ), and Version 3 estimates for 2002, with consistent back revision of the 2000 estimates, were published in the World Health Report 2003 ( WHO 2003b ).
The editors of the second edition of Disease Control Priorities in Developing Countries (DCP2) ( Jamison and others 2006 ) decided to use the Version 3 GBD estimates for 2001 to provide a common framework for assessing the causes of burden of disease in low- and middle-income countries and in analyzing priorities for interventions. We refer to these estimates as the GBD 2001. DCP2 measured the burden of disease in DALYs using a 3 percent discount rate, but without the nonuniform age weights used in the 1990 GBD study and in the results WHO published for 2000 to 2002.
This chapter documents the data sources and methods used to prepare the GBD 2001 estimates for DCP2 and provides an overview of the global and regional results for causes of disease and injury. The results presented here are those DCP2 used as a starting point for disease-specific economic and intervention analyses. The GBD 2001 incorporates a range of new data sources for developing internally consistent estimates of incidence, health state prevalence, severity, duration, and mortality for 136 major causes by sex and by eight age groups. It estimates deaths by cause, age, and sex for 226 countries and territories drawing on a total of 770 country-years of death registration data, as well as 535 additional sources of information on levels of child and adult mortality and in excess of 2,700 data sets providing information on specific causes of death in regions not well covered by death registration systems. Estimates of incidence, prevalence, severity, duration, and DALYs by cause, age, and sex drew on more than 8,500 data sources, including epidemiological studies, disease registers, and notification systems.
The results are presented here in terms of the World Bank's income and regional groupings of countries, which DCP2 used to facilitate matching causes of death and disease burden data with the economic and social data compilation in the World Development Report 2003 ( World Bank 2003 ). Countries are divided into seven groups: the high-income countries constitute one group and the low- and middle-income countries are divided into six geographical regions: East Asia and the Pacific, Europe and Central Asia, Latin America and the Caribbean, the Middle East and North Africa, South Asia, and Sub-Saharan Africa (see annex table 3A.1 and map 1 inside the front cover). Annex 3A includes tables documenting definitions of cause and sequela categories and regional categories and summarizing country-specific sources of information on mortality and causes of death and the disability weights used for each cause-sequela category. The tables in annexes 3B and 3C include results for the low- and middle-income countries as a whole as well as for the six regional groups.
