Disease Burdens and Disability-Adjusted Life Years in Aboriginal and Non-Aboriginal Populations

Abstract:

This chapter presents the methodology and some detailed results from the burden of disease and injury study, undertaken in 2000 by the NT Department of Health and Community Services, Australia (Zhao et al., 2004). In the disease and injury categories for which the data was available, this study followed closely the methods developed by WHO in Global Burden of Disease Study (Murray and Lopez, 1996) and AIHW in the Australian Burden of Diseases and Injury Study 1996 (Mathers et al., 1999). In the categories for which the data was unavailable, a hierarchical approach was adopted to choose the most appropriate method. This study provides a comprehensive assessment of the amount of ill health for both Aboriginal and non-Aboriginal people in the NT during the period 1994–1998.

Population mortality and morbidity attributive to 176 disease and injury categories were quantified by using a common currency – disability adjusted life years (DALYs). One DALY equals to 1 year lost due to premature death (YLL) or equivalent one healthy life year lost due to disability (YLD). YLL measures the mortality burden, whereas YLD gauges the disability burden.

The strength of using DALYs is that it summarizes both mortality and morbidity information, and facilitates meaningful comparisons when setting health care service priorities, identifying disadvantaged population groups and evaluating health interventions. Assessment of burden of disease estimates indicated that the YLL estimates were robust, as they were based on good quality mortality data. The quality of YLD data sources varied from “excellent” in disease surveillance systems to “reasonable” for the extrapolation method of national averages. The accuracy and precision of YLD estimates were not quantifiable, and therefore should be regarded as provisional and developmental.