Burden of chronic diseases

Chronic diseases and conditions are large contributors to the total burden of disease. A summary measure of the burden of disease is 'disability-adjusted life years' (DALYs). This is a measure of the years of healthy life lost due to illness or injury - one DALY is one lost year of 'healthy' life. DALYs are calculated as the sum of years of life lost due to premature mortality (YLL) and the equivalent years of 'healthy' life lost due to poor health or disability (YLD).

The only national estimates of DALYs for all diseases relate to data from 1996. In that year, the 12 chronic diseases covered on this web site accounted for about 42% of total DALYs. Coronary heart disease (CHD) was the major contributor to this total (Figure 1).

Figure 1: DALYs attributed to various chronic diseases and conditions, Australia, 1996

Source: AIHW: Mather C, Vos T, Stevenson C 1999. The burden of disease and injury in Australia. AIHW cat. No. PHE 17. Canberra: AIHW.

The mortality burden (YLL) is dominant in five of the chronic diseases (CHD, stroke, COPD, lung cancer and colorectal cancer). For the others, a greater proportion of the burden was from poor health and disability (YLD). For example, relatively few deaths are due to arthritis, asthma, oral diseases and osteoporosis, but these diseases still pose a significant burden in terms of poor health and disability. Depression is also in this category, and is the largest single contributor to YLD of all diseases.

Notes:

1. For further information on the methodology of DALY estimation, see the AIHW publication The burden of disease and injury in Australia
2. The International Classification of Diseases 9th Revision, was used for disease coding (click the link codes for detailed disease codes).
3. For other useful information, see the AIHW websites Burden of disease.

Last reviewed by on 23 June 2005