Rises in disability prevalence in the late 1990s were particularly marked among children aged 5-14, the older working age population and people aged 75 or over, according to a report released today by the Australian Institute of Health and Welfare.
And within these groups, Attention Deficit Hyperactivity Disorder (ADHD), the post-World War 2 baby-boomer population 'bulge', and the general ageing of the population have been singled out, respectively, as the most significant factors.
The report, Disability Prevalence and Trends, says overall rises in the number of people with a disability, especially those with a severe or profound core activity restriction, were also due in large part to substantial changes in survey methods between 1993 and 1998. These changes brought more people with a disability into the scope of the survey.
Senior Analyst with the AIHW's Functioning and Disability Unit, Dr Xingyan Wen, said that the increase in severe or profound core activity restriction among children applied especially to boys.
'The rates for boys aged 5-14 rose from 2.7% to 4.9% between 1993 and 1998, more than twice the average increase for males aged 15-64. For girls aged 5-14 the rates rose from 1.8% to 2.4%.'
The main area of increase in prevalence of disabling conditions in children was intellectual disabling conditions, of which most were reported as Attention Deficit Hyperactivity Disorder. Nearly 43,000 children reported it as a main or associated disabling condition in 1998.
'Higher levels of diagnosis and heightened awareness among parents, educators and health professionals may be the reasons behind the increase in reporting of ADHD', Dr Wen said.
Rises in disability prevalence among the older working age population reflected the passage of the post World War II baby-boom generation as it moves progressively up the population pyramid.
'This group is currently in their forties and fifties and is expected to affect future disability prevalence, especially the 55-64 year age group in the next 10 years', Dr Wen said.
'It's worth noting here the large rise in prevalence of musculoskeletal disorders in the working age population (6% rising to 8%) between 1993 and 1998. These disorders particularly affect older working age groups, both men and women.'
The ageing of the population aged 65 years and over has had a strong impact on prevalence of severe or profound restriction in older people.
Of the 1.1 million Australians estimated to have a severe or profound core activity restriction, 975,400 reported a physical/diverse disability, 398,300 reported a psychiatric disability, 301,900 an intellectual disability, 524,200 a sensory/speech disability, and 113,300 an acquired brain injury.