The Global Burden of Diseases, Injuries, and Risk Factors Study 2010 (GBD 2010) began in the spring of 2007 and is the most comprehensive effort since the GBD 1990 to produce complete and comparable estimates of the burden of diseases, injuries, and risk factors for the years 1990, 2005, and 2010 for 21 regions covering the entire globe.
The GBD 2010 is significantly broader in scope than previous versions, including:
- 291 diseases and injuries
- 67 risk factors
- 1,160 sequelae (nonfatal health consequences)
- Estimates for 21 regions
- Estimates for 20 age groups
- Improved methods for the estimation of health state severity weights
The GBD 2010 has brought together a large community of experts and leaders in epidemiology and other areas of public health research from around the world to measure current levels and recent trends in all major diseases, injuries, and risk factors and to produce new and comprehensive sets of estimates and easy-to-use tools for research and teaching.
The principle guiding the burden of disease approach is that the best estimates can only be generated by analyzing all available sources of information in a country or region and correcting for bias. The results are presented in terms of disability-adjusted life years (DALYs), a time-based measure that combines years of life lost due to premature mortality and years of life lost due to time lived in health states less than ideal health, a metric that was specifically developed to assess the burden of disease.
The GBD 2010 is a collaboration of hundreds of researchers around the world, led by the Institute for Health Metrics and Evaluation at the University of Washington and a consortium of several other institutions including:
- Harvard University
- Imperial College London
- Johns Hopkins University
- University of Queensland
- University of Tokyo
- World Health Organization (WHO)
The GBD Study has undertaken several key activities to produce global burden estimates:
1. Produced valid, unbiased, and comparable estimates of prevalence of disease and injury cases or episodes and relevant disabling sequelae at the population level for the GBD regions
Together with information on duration, distribution by severity, and corresponding health state severity weights has been used to estimate the years lived with disability (YLD) by age and sex for all 21 regions of the world for 1990, 2005, and 2010. A large number of systematic reviews have been implemented by condition-specific experts around the world, accessing published and grey literature, to collate the data used to derive these estimates.
2. Produced cause-specific mortality by region that collectively sums to all-cause mortality estimates globally
3. Revised the health state severity weight system, a highly debated component of past GBD studies that seeks to measure health state severity
There are 1,160 sequelae, that result from one or more of the conditions being assessed for the GBD Study. A health state severity weight assigns each sequela a value representing a state between perfect health (0) and death (1). Health state severity weights provide the bridge between mortality and nonfatal outcomes in the burden of disease. The original GBD Study used expert opinion to assign these weights for each sequela. The current study utilizes household surveys fielded in a diverse set of cultural, demographic, and linguistic contexts as well as one made available on the Web.
The survey asks individuals to imagine different health outcomes and compare them to each other in simple, comprehensible questions for all educational levels. For example: “Imagine two people – the first person is completely blind, and the second person suffers from constant intense back pain. Who is healthier overall?” Answers are used to calculate a health state severity weight for each sequela.
4. Produced estimates of YLDs, YLLs, death, and DALYs for diseases, injuries, and risk factors for 21 regions for 20 age groups and both sexes, for 1990, 2005, and 2010
In order to maximize comparability across time and between conditions, the GBD Study is applying newly updated methods across all data. It will utilize analytic tools developed within several research teams at IHME to ensure high quality results that maximize the use of the data that have been identified through systematic reviews.
The estimates will include 291 diseases and injuries, and 67 risk factors – the single most comprehensive study of its kind carried out to date.
History of the GBD Study
The original Global Burden of Disease Study (GBD 1990) was commissioned by the World Bank in 1991 to provide a comprehensive assessment of the burden of 107 diseases and injuries and 10 selected risk factors for the world and eight major regions. The methods established by that study created a common metric to estimate the health loss associated with morbidity and mortality.
The study represented a major step in quantifying global and regional effects of diseases, injuries, and risk factors on population health. It also stimulated numerous national studies of burden of disease. The results have been used by governments and non-governmental agencies to inform priorities for research, development, policies, and funding.
Improving the health and well-being of the world’s population is a moral imperative and essential for global stability and progress. The vast energies, technologies, and resources pouring into global health have given us the capacity to fight disease, remedy disability, and address deep inequalities in health between populations.
The new round of the Global Burden of Diseases, Injuries, and Risk Factors Study will provide the tools and knowledge to inform efforts for making truly effective interventions possible. The GBD 2010’s consistent and comprehensive regional estimates will help policymakers and nonresearch audiences interpret GBD concepts and utilize study results.