Drivers of change in risk factor attributable burden

This chapter presents new analyses undertaken using data from the Australian Burden of Disease Study 2015 to explore the different drivers of change over time in burden of disease attributable to 5 selected risk factors: tobacco use, alcohol use, overweight and obesity, high blood pressure and dietary risk factors.

The disease burden attributed to a selected risk factor is referred to as ‘attributable burden’ and is measured in terms of Disability Adjusted Life Years (or DALY). It reflects the reduction in fatal burden (measured by years of life lost (YLL)) and non-fatal burden (measured by years lived with disability (YLD)) that would have occurred if exposure to the risk factor had been avoided or reduced to its lowest level. For more information on how attributable burden is calculated, see Australian Burden of Disease Study: methods and supplementary material 2015.

Between 2003 and 2015, there was an 11% increase in the total number of DALY attributed to all risk factors included in the Australian Burden of Disease Study (for those that were measured in both 2003 and 2015). Note this is different to changes in the age-standardised rate of attributable DALY per 1,000 population (which was 76.7 DALY per 1,000 in 2003 and 65.3 DALY per 1,000 in 2015).

The main factors contributing to the increase in the total number of attributable DALY were population growth (the Australian population increased by 21% between 2003 and 2015), population ageing, changes to exposure to the risk factor in the population, and changes in the amount of burden for diseases linked to each risk factor. These 4 factors and the method used to estimate the contribution of each to changes in attributable burden, are explained further in the box below.

Key results from these analyses for the 5 selected risk factors can be found in the data visualisations below and in Table S2.