Flinders University experts have played an important role in “the largest ever systematic effort to describe the global distribution and causes of a wide array of major diseases, injuries and health risk factors”.

The Global Burden of Disease Study 2010 (GBD), published in December in The Lancet, had its ‘regional launch’ in Melbourne in May.

Professor Konrad Pesudovs, Head of Optometry and Vision Science at Flinders, and Professor James Harrison, Director of the Research Centre for Injury Studies, were among some 500 researchers worldwide who took part in the study.

As members of the vision loss expert group, Professor Pesudovs and his colleagues conducted a comprehensive survey of epidemiological studies of eye disease.

“There are two aspects to the GBD: there’s the counting of people with health problems; and there’s the disability weights, which express how important those problems are [on a scale of 0 – representing perfect health – to 1, which is equivalent to death],” Professor Pesudovs said.

“You multiply the two figures to determine the burden of disease,” he said.

One finding of study is that while men and women worldwide have gained slightly more than ten years of life expectancy overall since 1970, they spend more years living with injury and illness.

Similarly, while fewer children are dying every year, more young and middle-aged adults are dying and suffering from disease and injury.

However, there were some surprises within the disability weights.

“When you look at the results, the sensory impairments like hearing loss and vision loss and some of the physical impairments like, like amputation, have come up with surprisingly low weights,” Professor Pesudovs said.

“And there are some things that are surprisingly high: mild drug abuse, mild alcohol abuse, pain in the neck,” he said.

Professor Pesudovs, whose concerns have been raised in The Lancet, believes the discrepancy lies in the nature of questions put to respondents about how they compared unrelated conditions.

“The questions asked, ‘Which of these two people is healthier? The blind person or the mild alcoholic?’ They didn’t ask, ‘Which of these persons is more able to engage in their life or who’s got a better life or worse life?’ They asked who is healthier. We think this is a serious problem for the results.”

Despite these reservations, Professor Pesudovs said he remains a strong advocate of the GBD and was pleased to be involved.

“It’s highly valuable to people who decide where resources go because they can think about where best to spend their money,” he said.

Professor James Harrison, who led with injury expert group with Dr Kavi Bhalla from the Johns Hopkins Center for Global Health, agrees.

“The GBD is definitely a worthwhile endeavour and it’s important to recognise just what an enormous endeavour it is,” Professor Harrison said.

He said that one of the virtues of the GBD is that, in addition to providing estimates of the burden of disease that are “probably as good as anyone else’s”, it does so for all conditions.

“One very special property of the GBD is that it covers the whole spectrum of types of conditions – and it attempts to deal with both deaths and non-fatal cases. It’s a special kind of lens,” he said.

“That’s helpful for politicians and health ministers who, as you can imagine, are always being harangued to give money to everybody’s favourite cause. The GBD results bounce responsibility back on advocates for individual conditions to argue their case in a way that also takes account of the impact of other conditions.”

Another important aspect of the GBD, and one that Professor Harrison and colleagues in Australia and elsewhere will now pursue independently, is that it has driven improvements in the search for injury data and the methods to analyse them.

“Ten or 20 years ago, many of us would have had rather simplistic views about how much data there is on this or that topic, in some ways over-optimistic and in some ways underestimating what is really there.

“When you actually go and look, you can be quite surprised by what is actually there and but also by the extent of some of the gaps.”

Professor Harrison added, however, that the nature of the GBD did have a downside.

“There is a risk that things like the GBD become ‘inviolate’, or unchallengeable,” he said.

“The GBD 2010 project was so large, complex and expensive that it would be hard for others to replicate. There is a potential risk in having only one primary source of global estimates of health burden.”