The top-line results of the Global Burden of Disease (GBD) 2013 study indicate that the average global life expectancy has risen faster than healthy life years from 1990 to 2013. This appears to suggest that although people are living longer on average, they are not doing so free from disease or disability.
IHS Life Sciences perspective | |
Significance | The Global Burden of Disease (GBD) 2013 study, a well-respected survey of disease trends and life expectancy, has been published showing that global life expectancy at birth increased by 6.2 years between 1990 and 2013. In the same period, healthy life expectancy increased 5.4 years. |
Implications | The increase in life expectancy but slower increase in healthy life expectancy suggests that although the global population is living longer, it is not doing so in better health. An additional component of the study indicated a limited link between socio-economic status and disability-adjusted life years (DALYs) attributed to non-communicable diseases. |
Outlook | Without intervention, the burden of disease from non-communicable diseases could place a significant burden on healthcare provision in the future. |
Highest and lowest life expectancies, 2013 | |||
Highest | Lowest | ||
1 | Japan | 10 | Zambia |
2 | Singapore | 9 | South Sudan |
3 | Andorra | 8 | Chad |
4 | Iceland | 7 | Afghanistan |
5 | Cyprus | 6 | Mozambique |
6 | Israel | 5 | Zimbabwe |
7 | France | 4 | Guinea-Bissau |
8 | Italy | 3 | Central African Republic |
9 | South Korea | 2 | Swaziland |
10 | Canada | 1 | Lesotho |
Source: GBD 2015 | |||
The Institute for Health Metrics and Evaluation has published top-line results from its Global Burden of Disease 2013 study on global health. In terms of life expectancy, the survey results show that life expectancy (for both sexes) was 71.5 globally during 2013, an increase of 6.2 years on life expectancy in 1990. Looking at healthy life expectancy (HALE, defined as life free from disease or disability) was 62.3 years in 2013, an increase of 5.4 years on 1990 levels. The fact that life expectancy has increased faster than healthy life expectancy suggests that populations are living longer, but in poorer health.
Increases in healthy life expectancy were not seen across the board globally. Although there were countries such as Nicaragua and Cambodia where HALE increased by 14.7 and 13.9 years, respectively, people in countries such as Botswana and Belize experienced declines of two and 1.3 years, respectively, in HALE over the 23-year period. The study also notes startling variation on a regional basis; newborns in Thailand had a HALE of 67 years in 2013, compared with newborns in neighbouring Cambodia who had a HALE of 57.5 during the same year.
Broadly, across the world, the number of disability-adjusted life years (DALYs, defined as years lost to disease or early death) due to non-communicable diseases has increased, from 1.08 billion in 1990 to 1.43 billion in 2013. Over the same period, that of DALYs caused by communicable diseases has declined, from 1.19 billion to 769.3 million. Significant progress appears to have been made in reducing DALYs from maternal, neonatal, and nutritional disorders. The study notes that although DALY's lost to HIV increased 341.5% over the period, they declined 23.9% from 2005.
Leading causes of DALYs | |
1 | Ischaemic heart disease |
2 | Lower respiratory infection |
3 | Stroke |
4 | Low back and neck pain |
5 | Road injuries |
6 | Diarrheal diseases |
7 | Chronic obstructive pulmonary disease |
8 | Neonatal preterm birth complications |
9 | HIV/AIDS |
10 | Malaria |
Source: GBD, 2015 | |
Outlook and implications
The survey seeks to collect data on death and disease in 188 countries, covering 306 diseases. It therefore provides a useful barometer of global health trends internationally and a useful tool for public health planners.
One of the messages emanating from the survey – the decline in DALYs due to communicable diseases alongside the increase those from non-communicable illnesses – has been known for some time. However, although the trends appear to show a steady increase in DALYs from non-communicable diseases up until now, we may expect a more dramatic shift in the longer term. Indeed, with areas such as the Gulf experiencing high numbers of pre-type 2 diabetes sufferers and rates of tobacco and alcohol consumption rising in regions such as Sub-Saharan Africa, the global health outlook may lurch towards more dramatic increases in incidence of communicable diseases in the future. Seeing off this trend will require a significant global effort and attempts in poorer countries to strengthen healthcare to meet these challenges. This is achievable given that health systems have been improved to reduce the burden of communicable diseases, with significant success.
Interestingly, the study sought to examine if socio-demographic status played a part in health loss. To do this, the researchers examined per-capita income, population age, fertility rates, and schooling, and compared these with health rates. The results of this component of this study suggested that these factors could be responsible for around half of the differences in DALYs lost to maternal and neonatal disorders. However, these factors did not appear to be so significant for rates of type 2 diabetes and cardiovascular conditions. This is an interesting point, as it is typically assumed that socio-economic status plays a significant part in all aspects of a patient's health – be that risk of contracting disease, survivability, and ongoing impact of that disease/disorder on a patient's life.