A 30-year global study has analysed 286 causes of death, 369 diseases and injuries, and 87 risk factors in 204 countries and territories.
The latest findings from the Global Burden of Disease Study (GBD) were published this month in The Lancet, providing new insights on how well countries were prepared in terms of underlying health for the COVID-19 pandemic, and setting out the true scale of the challenge to protect against further pandemic threats.
The study – the work of more than 5647 collaborators, including several UNSW academics – also reveals that the rise in exposure to key risk factors (including high blood pressure, high blood sugar, high BMI, and elevated cholesterol) combined with rising deaths from cardiovascular disease in some countries, suggests the world might be approaching a turning point in life expectancy gains.
Healthy life expectancy in Australia – the number of years a person can expect to live in good health – has increased steadily over the past three decades to 70.0 years in Australia (a 4.1 year increase from 1990) in 2019, but it has not risen as much as overall life expectancy (82.9, a 5.9 increase from 1990), indicating that people are living more years in poor health.
Co-author Professor Perminder Sachdev, Co-Director, UNSW Sydney Centre for Healthy Brain Ageing (CHeBA), said a significant proportion of the gap between health span and life span was due to brain diseases, in particular dementia. “It is interesting that the most common risk factors identified by the GBD study are also risk factors of dementia and controlling them could offer a lifetime of good health,” he said.
Co-author Scientia Professor Philip Mitchell from UNSW Medicine’s School of Psychiatry said the study was the pre-eminent source of data on global disease patterns, with the capacity to track changes in health.
“While life expectancy continues to increase internationally, the pattern of disease burden is changing dramatically, with an increasing proportion being due to disability from conditions such as musculoskeletal disorders, mental illness and substance use, and a corresponding decrease in the proportion of burden due to premature mortality – particularly that due to infectious disease and maternal and child illness.”
Prof. Mitchell said while universal health coverage was improving worldwide, many health systems had not adapted to the rapid change in the pattern of disease burden from premature death to increased disability.
“There is a growing need for investment in innovative interventions to reduce this growth in the impact of disability,” he said.
Ischaemic heart disease was the leading cause of poor health in Australia and New Zealand in 2019, followed by low back pain, falls, chronic obstructive pulmonary disease, and depressive disorders.
The top five risk factors for death in Australia in 2019 were high systolic blood pressure (contributing to an estimated 25,500 deaths), dietary risks (21,600 deaths), tobacco use (20,100), high BMI (18,700), and high blood sugar (17,700).
Co-author Professor Alta Schutte from UNSW Medicine and The George Institute for Global Health said the continued comprehensive updates by the Global Burden of Disease Collaborators provided invaluable information on critical areas to address.
“It remains highly concerning to me – working in the field of hypertension and cardiovascular disease – that raised systolic blood pressure remains the leading global risk factor, contributing to 10.8 million deaths in 2019,” she said.
“World Hypertension Day, recently held on 17 October 2020, is an important reminder on why we need to check our blood pressure regularly, and ensure that it is controlled to save lives.”
Injury epidemiologist Associate Professor Soufiane Boufous from UNSW Science’s Transport and Road Safety (TARS) Research Centre said key findings included the progress made in terms of occupational injury.
“This was the leading risk factor in 1990 among youth aged 10-24 years (3.2 per cent of Disability Adjusted life Years), but in 2019 it was the fifth risk factor (1.8 per cent of Disability Adjusted life Years),” he said.
Over the past 30 years, overall rates of death among 15-49-year-olds declined by 31 per cent in Australia. However, rates of death due to drug use disorders rose substantially in this age group (by 55.2 per cent), as did rates of death due to endocrine, metabolic, blood, and immune disorders (by 75.2 per cent).
Professor Louisa Degenhardt, Deputy Director of UNSW Medicine's National Drug and Alcohol Research Centre (NDARC), said alcohol and drug use attributable burden had increased consistently since 1990, and increased at a higher rate in the past decade.
“Drug use increased from tenth to eighth-biggest risk factor from 1990-2019 among 25-49-year-olds, and is now 2.9 per cent of global attributable burden,” she said.
“In Australasia in 2019, tobacco is the number one risk factor. Alcohol is the sixth-largest risk factor and drug use is the ninth, increasing more than 1 per cent per year.”
The GBD is produced by a global network of 5647 collaborators in 152 nations and territories and who are working in more than 1100 universities, research centres, and government agencies.
Dr Amy Peden from UNSW Medicine’s School of Population Health said she was thrilled to play a role in disseminating the data and insights the world needs to make evidence-informed decisions to improve global health and wellbeing.
“In particular, I’m passionate about highlighting the burden of injury-related harm and working to prioritise strategies to reduce the burden,” she said.
Raaj Kishore Biswas from TARS has been part of the collaboration for Bangladesh and Australia.
“This study, overall, catches the magnitude of diseases and injuries worldwide that complements national estimates, policies and most importantly, will evaluate how global funds should be distributed,” he said.
The GBD has been used to inform health policies in numerous nations and local jurisdictions, as well as international organisations, including the World Bank and the World Health Organization.
UNSW co-authors on the paper include: