Mortality and Cause of Death in People on the Autism Spectrum: An Exploration of State-Based Administrative Data.

Background:

Examination of mortality and cause of death is of central importance for understanding the extent and nature of health inequalities for adults with autism spectrum disorder (ASD). Previous studies indicate that this population experiences 2 to 5.6 times higher mortality rates than the general population. Whilst respiratory disease and nervous system disorders are leading causes of death, unnatural and avoidable events, such as accidents and suicide, are also notable causes. In addition to the general paucity of information regarding health and wellbeing outcomes for adults on the autism spectrum, there has been limited investigation of mortality and cause of death.

Research concerning mortality and cause of death is of key importance for the evaluation and planning of health services and policy. Robust analysis of large linked data sets provides representative and timely information for such evaluation and planning.

Objectives:

To examine mortality rates and cause of death for adults with ASD, intellectual disability and both in comparison to the general population in New South Wales (NSW), Australia.

Methods:

Nine NSW state-based retrospective datasets have been linked as part of a larger project exploring the health and wellbeing of people with intellectual disabilities. These datasets cover the period of 2005/06 to 2011/12. We expect to have extended datasets (up to 2015/16) available for analysis and presentation by early 2017.

For the current study, the ASD cohort was identified primarily through the Disability Services Minimum Dataset. Mortality and cause of death data were obtained from the NSW Attorney General and Justice Register of Births, Deaths and Marriages (RBDM) and from the Australian Bureau of Statistics (ABS). Population size, mortality and cause of death in the general population in NSW were accessed via the ABS data.

We will compare data for four groups: (i) ASD only, (ii) intellectual disability only, (iii) ASD and intellectual disability; and (iv) the general population in NSW. Descriptive statistics will be used to describe causes of death. Other analyses will include age-specific crude death rates, standardised mortality rates and Comparative Mortality Figure (CMF) and years of potential life lost (YPLL).

Results:

In our existing data n=15,983 adults with ASD only, n=42,243 adults with intellectual disability only, and n=7,497 adults with both ASD and intellectual disability were identified to have accessed disability services in NSW between 2005/06-2011/12. We anticipate that for the extended dataset, this cohort will increase substantially (at least n=20,000 adults with ASD only, n=60,000 adults with ID only and n=10,000 adults with both ASD and intellectual disability).

Conclusions:

This study will provide the most reliable and current information on mortality and cause of death in adults on the autism spectrum in Australia. Due to the nature of the data, it will include a wider sample of individuals on the autism spectrum than any other Australian study. This information will be of intense interest to health professionals, service providers and families, and will help shape efforts to address premature death for this population.