Abstract
Over the last 30 years, HIV/AIDS has emerged as a major global health challenge. Globally, the trend is that non-communicable diseases and injuries are accounting for a larger share of disease burden, but HIV/AIDS is a notable exception. Maintaining and expanding the response to the epidemic will require assessment of its magnitude and impact at the country level. It is also critical to examine the HIV/AIDS epidemic in the context of other health problems to clearly understand its impact and effectively allocate resources. To this end, its levels and trends must be measured in units, such as disability-adjusted life years, or DALYS, that allow comparison with other major conditions. The authors used the metrics and data produced by the Global Burden of Diseases, Injuries, and Risk Factors Study 2010 (GBD 2010) to assess where HIV/AIDS remains a dominant cause of health loss and where disease burden is still increasing.
Analytical approach
In GBD 2010, DALYs are used as a key measurement of disease burden. DALYs are the sum of years of life lived with disability (YLDs) and years of life lost to premature mortality (YLLs). YLDs are disability-weighted prevalence estimates and YLLs are the difference between age of cause-specific death and an ideal lifespan. Researchers derived DALY estimates for HIV/AIDS from the UNAIDS 2012 prevalence estimates, the GBD 2010 disability weights, and their own custom estimates. The custom mortality model arrived at estimates on a country-by-country basis. For 36 countries with complete and high-quality vital registration systems, researchers used CODEm, the standard GBD 2010 cause of death model, so the estimates would make best use of the available data. For the remaining countries where cause of death data was not sufficient for analysis, because there were either too few deaths recorded or systematic misclassification of deaths in vital registration or verbal autopsy studies, researchers used UNAIDS 2012 estimates.
Findings
Researchers found that global HIV/AIDS mortality peaked in 2006 and has been steadily declining at an average annual rate of 4.17% ever since. The decline in HIV/AIDS mortality reflects both declining incidence in some settings as well as the impact of the rapid scale-up of antiretroviral therapy (ART) in some countries with large epidemics. HIV/AIDS was the 33rd most important cause of burden in 1990 and increased dramatically to the 5th cause of burden in 2010. In absolute terms, the burden of HIV increased during that period by 354%.
The distribution of HIV/AIDS burden is not equal across demographics. In 2010, HIV/AIDS was the leading cause of DALYs for both males and females aged 30 to 44. It is also not equal across regions. In 2010, HIV/AIDS was the leading cause of DALYs for 21 countries that fall into four distinctive blocks: Eastern and Southern Africa, Central Africa, the Caribbean, and Thailand. While HIV/AIDS is a global epidemic, a majority of the disease burden is concentrated in a handful of countries with particularly large epidemics. HIV/AIDS is ranked within the top five causes of burden in 26 countries.
Conclusions
The burden of HIV/AIDS has declined in the last half decade, which is likely attributable to declines in incidence, massive scale-up of ART coverage, and increased efforts to prevent transmission from mothers to their children. Clear and compelling links between donor funding for ART programs and scale-up provide strong evidence on the impact of some investments. Despite progress, however, the message is clear: HIV/AIDS is still very much a global problem. The global HIV/AIDS community will need to increasingly focus its attention on settings where the disease is not yet a dominant health problem. Several studies have shown the cost savings and health benefits that can occur if low-burden countries invest in HIV/AIDS prevention now. This may require different political and technical strategies moving forward.
The GBD effort will be updated to provide accurate and timely estimates of disease burden at the country, regional, and global levels. This data can foster a sustained, coherent response to the HIV/AIDS epidemic and other current and future global health challenges.
