Last fortnight’s blog post featured a synopsis of the mighty Global Burden of Disease Study on life years lost across different countries and across the world over time due to different diseases. A subsequent paper has recently been published in the Lancet that uses a standardised framework and method to estimate summary measures of health loss expressed as DALYs and Health Life Expectancy. Health loss was estimated for 306 diseases/conditions across 188 countries at regular intervals between 1990 and 2013. Headline messages from this 46 page study are as follows:
- Worldwide life expectancy rose by 6.2 years (from 65 to 71 years) over the 23 years of the study.
- Age-standardised DALYs fell by a mighty 27%.
- Indicators (total DALYs and age-specific DALYs) improved dramatically for communicable diseases; and for maternal, neonatal and nutritional diseases.
- Age-adjusted DALYs have also declined for non-communicable disease – a surprise?
- Some communicable diseases (notably leishmaniasis and dengue) bucked the trend for communicable diseases as a whole and registered a recent increase in DALYs. The CLAHRC WM Director questions the finding regarding leishmaniasis – he suspects that visceral leishmaniasis, at least, is declining.
- The greatest causes of DALYs were ischaemic heart disease, pneumonia, stroke, spinal pain, and road injuries. The CLAHRC WM Director suspects that mental illness is underestimated in this study?
- Leading causes of DALYs are highly variable across countries.
- Progress has been most rapid in the latter part of the survey period thanks to major reductions in HIV/AIDS and malaria, along with maternal, neonatal and nutritional disorders.
- DALY rates for neoplasms and cardiovascular disease are minimally related to socio-economic status except that risk for cardiovascular disease drops at the very highest economic level.
The health of the world’s population really has improved and to quite a dramatic degree. This has happened even in countries that have not prospered economically. The GBD study is a remarkable achievement, up there with the human genome project. It shows that science is a massive public good, and is a stark vindication of Enlightenment values and investment in research.
— Richard Lilford, CLAHRC WM Director
- GBD 2013 DALYs and HALE Collaborators. Global, regional, and national disability-adjusted life years (DALYs) for 306 diseases and injuries and health life expectancy (HALE) for 188 countries, 1990–2013: quantifying the epidemiological transition. Lancet. 2015; 386: 2287-323.