What scenarios did we examine?

Attributable burden is the amount by which disease burden could be reduced if exposure to the risk factor had been avoided or reduced to the lowest possible exposure. For example, the attributable burden for physical inactivity is the amount of illness and death that could be avoided if everyone was active enough to maintain a minimum risk of developing disease. This is quantified by using burden of disease measures, including the disability-adjusted life year (DALY). See the Technical notes section for a detailed description of data sources and methods used to calculate attributable burden.

What are disability-adjusted life years?

Disability-adjusted life years (or DALY) is a measure used in burden of disease analysis. It counts the combined years of healthy life lost through either premature death or living with disability due to illness or injury.

The modelling in this report explored the impact of hypothetical scenarios on disease burden in the year 2030 to align with national preventive health targets. See National health strategies for an overview of these targets.

This work builds on the latest methods used in the Australian Burden of Disease Study (ABDS) 2018 to extend earlier scenario modelling that estimated burden attributable to overweight (including obesity) and physical inactivity (AIHW 2021). For both risk factors, the scenarios are:

  • The stable scenario: estimated attributable burden in 2030 if the prevalence of living with overweight (including obesity) and levels of physical activity were to stay as they were in 2018.
  • The target scenarios: estimated attributable burden in 2030 if the population at risk in 2017–18 improved their exposure to the risk factor. The analysis looked at 3 scenarios for overweight (including obesity) and 6 scenarios for physical inactivity (Table 1).
  • A trend scenario: for overweight (including obesity), estimated attributable burden in 2030 if current trends in exposure were extended to 2030.

Trends in BMI were based on measured height and weight from successive health surveys of the Australian population by the Australian Bureau of Statistics. However, due to changes in the collection of self-reported data over time from successive surveys, a trend scenario for physical activity was not included. See the Technical notes section for more information.

Table 1a: Summary of target scenarios of improved BMI exposure

Overweight (including obesity)

Reduced BMI by 1 kg/m2

Reduced BMI by 2 kg/m2

Reduction in obese population’s BMI to overweight (but not obese) classification

Table 1b: Summary of target scenarios of improved physical activity exposure

Physical inactivity

Additional 15 mins of moderate-intensity activity per week

Additional 30 mins of moderate-intensity activity per week

Additional 60 mins of moderate-intensity activity per week

Additional 15 mins of moderate-intensity activity, 5 days a week
Additional 30 mins of moderate-intensity activity, 5 days a week
Additional 60 mins of moderate-intensity activity, 5 days a week

Note: Refer to the technical notes for more information on data sources and methods used to examine these scenarios.