Technical appendix on the ABS 2003 Survey of Disability, Ageing and Carers

A.1 The Survey

The 2003 Survey of Disability, Ageing and Carers (ABS 2004) was conducted throughout Australia during the period June to November 2003. The aims of the survey were to:
* measure the prevalence of disability in Australia;
* measure the need for support of older people and those with a disability;
* provide a demographic and socioeconomic profile of people with disabilities, older people and carers compared with the general population; and
* estimate the number of and provide information about people who provide care to older people and people with disabilities.

Information was collected from the three target populations:
* people with a disability;
* older people (i.e. those aged 60 years and over); and
* people who care for persons with a disability and older people.

The survey covered people in both urban and rural areas in all states and territories, except for those living in remote and sparsely settled parts of Australia. It included people in both private and non-private dwellings, including those in cared accommodation establishments but excluding those in gaols and correctional institutions

Collection Methods

Different data collection methods were used for the household component and the cared-accommodation component of this survey.

Data for the household component were collected by trained interviewers, who conducted computer-assisted personal interviews. Where possible, a personal interview was conducted with people identified in any of the three target populations. Proxy interviews were conducted for children aged less than 15 years, for those aged 15-17 years whose parents did not permit them to be personally interviewed, and for those with a disability that prevented them from having a personal interview.

Cared accommodation includes hospitals, homes for the aged such as nursing homes and aged care hostels, cared components of retirement villages, and other 'homes' such as children's homes. The cared-accommodation component was enumerated in two stages using a mail-based methodology directed to administrators of selected establishments who then selected survey participants using instructions provided by the ABS. A separate questionnaire was completed for each selected occupant meeting the coverage requirements.

The key measures used in the survey are described below.

A.2 Disability

For ABS survey purposes, a person has a disability if he/she has at least one of the following 17 limitations, restrictions or impairments, which has lasted, or is likely to last, for at least 6 months and restricts everyday activities (ABS 2004:72-3):
* loss of sight, not corrected by glasses or contact lenses;
* loss of hearing, with difficulty communicating or use of aids;
* speech difficulties (including speech loss);
* chronic or recurring pain or discomfort that restricts everyday activities;
* shortness of breath or breathing difficulties that restrict everyday activities;
* blackouts, fits, or loss of consciousness;
* difficulty learning or understanding;
* incomplete use of arms or fingers;
* difficulty gripping or holding things;
* incomplete use of feet or legs;
* a nervous or emotional condition that restricts everyday activities;
* restriction in physical activities or in doing physical work;
* disfigurement or deformity;
* head injury, stroke or any other brain damage with long-term effects that restrict everyday activities;
* needing help or supervision because of a mental illness or condition;
* receiving treatment or medication for any other long-term condition or ailment and still restricted in everyday activities; and
* any other long-term condition that restricts everyday activities.

The survey definition of disability aims to capture a broad range of people who have one or more impairments or limitations, or who have one or more health conditions which restrict everyday life. Thus, the 17 items were used as criteria to create the base 'disability' population which is the starting point for prevalence estimates.

Activity Limitations and Their Severity

A 'specific limitation or restriction' is defined in the 2003 survey as a limitation in core activities (self-care, mobility and communication) or a restriction in schooling or employment. People who were identified as having a disability (using the above 17 criteria) and all people aged 60 years or over, were asked about their difficulty and need for assistance with various daily activities: self-care, mobility, communication, health care, housework, property maintenance, paperwork, meal preparation, transport, and cognition or emotion. Cognition or emotion refers to interacting, making or maintaining relationships, coping with feelings or emotions, making decisions or thinking through problems.

In the survey four levels of core activity limitation were determined, based on whether a person needs personal assistance with, has difficulty with, or uses aids or equipment for any of the core activities. A person's overall level of core activity limitation is determined by the highest level of limitation the person experienced in any of the core activity areas. The four levels of core activity limitation are:
* profound - unable to perform a core activity or always needing assistance;
* severe - sometimes needs assistance to perform a core activity, or has difficulty understanding or being understood by family or friends, or can communicate more easily using sign language or other non-spoken forms of communication;
* moderate - does not need assistance, but has difficulty performing a core activity; and
* mild - has no difficulty performing a core activity but uses aids or equipment because of disability; or cannot perform the activities of easily walking 200 metres, walking up and down stairs without a handrail, easily bending to pick up an object from the floor, and using public transport; or can use public transport but needs help or supervision; or needs no help or supervision but has difficulty using public transport.

Core activities comprise the following tasks contributing to the definition of profound or severe core activity limitation:
* self-care - bathing or showering, dressing, eating, using the toilet, and bladder or bowel control;
* mobility - getting into or out of a bed or chair, moving around at home and going to or getting around a place away from home; and
* communication - understanding and being understood by others: strangers, family and friends.

Four Sets of Prevalence Estimates of Disability Groups

In Australia, the five disability groups 'intellectual/learning disability'; 'psychiatric disability'; 'sensory/speech disability'; 'physical/diverse disability'; and 'acquired brain injury' provide a broad categorisation of disabilities based not only on underlying health conditions and impairments but also on activity limitations, participation restrictions and related environmental factors. These groups are generally recognised in the disability field and in legislative and administrative contexts in Australia (NCSDC 2004).

Four main approaches have been used to obtain estimates of disability (see Table 5.2). These provide a spectrum of estimates that may suit different purposes. All the estimates start with the base 'disability population', that is those defined by the survey as having a disability.

Estimates based on 'main disabling condition' relate to the condition that was identified by the survey respondents as causing the most problems, compared with any other conditions he or she may also have had. Using this method, the estimates of different disability groups are exhaustive and mutually exclusive. The numbers in each group total the number of people with a disability, as defined by the 2003 survey. People may, however, experience more than one disabling condition. The prevalence of a particular disability group will be underestimated if only main disabling conditions are considered. This approach to estimation is used when the focus is on people and each person is to be counted only once.

The remaining three sets of estimates are based on all disabling conditions and are in diminishing size, corresponding to an increasingly restrictive scope, according to severity, need for assistance or activity limitation:
* all disabling conditions
* all disabling conditions, plus activity limitations and participation restrictions
* all disabling conditions, plus severe or profound core activity limitations.

These estimates provide a better indication of the prevalence of particular disabilities. (See AIHW 2003:343 for more details.)

A.3 Long-term Health Condition

In the survey, a long-term health condition is defined as a disease or disorder which has lasted or is likely to last for at least 6 months; or a disease, disorder or event (e.g. stroke, poisoning, accident, etc.) which results in an impairment or restriction which has lasted or is likely to last for at least 6 months (ABS 2004:76). In other words, people may have a long-term health condition, but not a disability, if the health condition does not result in an impairment or restriction which has lasted or is likely to last for at least 6 months. Long-term health conditions have been coded to a classification based on the World Health Organization's International Classification of Diseases and Related Health Problems (WHO 1992).

References

ABS (Australian Bureau of Statistics) 2004. Disability, ageing and carers: summary of findings, Australia 2003. Cat. no. 4430.0. Canberra: ABS.

AIHW (Australian Institute of Health and Welfare) 2003. Australia's welfare 2003. Canberra: AIHW.

NCSDC (National Community Services Data Committee) 2004. National community services data dictionary. Version 3. Canberra: AIHW.

WHO (World Health Organization) 1992. International classification of diseases and related health problems. 10th revision. Geneva: WHO.