Understanding disability statistics in the Census and the Survey of Disability, Ageing and Carers

An explanation of disability data available in the Census and other ABS sources


Collecting data on disability statistics

The Census collects information on whether a person has a need for assistance with core activities due to a long-term health condition, a disability or old age. Core activities are defined as those which are essential to everyday living: self-care, mobility and communication. This aims to identify people with more severe forms of disability that need personal support, rather than being a broad measure of people with a disability. The Survey of Disability, Ageing and Carers (SDAC) collects a broad range of information about people with a disability including levels of severity. It is the recommended source of disability prevalence data in Australia.

Knowing more about the needs of people with disability contributes to the evidence base for informing policies and planning to drive better outcomes. The SDAC asks many more questions than the Census and therefore also collects information about those with less severe disabilities. This conceptual paper provides information on the differences, strengths and key uses of disability-related data from each of these collections.


The Census provides a rich snapshot of all people in the country on Census Night and is the leading source of information for small population groups and areas. It collects a range of information about the number and key characteristics of the Australian population, including:

  • core activity need for assistance
  • age
  • ethnicity
  • income
  • education
  • employment
  • living and housing arrangements.

We use responses to the core activity need for assistance questions to identify people who require assistance with self-care, mobility or communication. The Census core activity need for assistance measure is conceptually comparable to the SDAC concept of 'Profound or severe core activity limitation', the population for whom service delivery has the most consequence. Census data helps service providers and governments plan what local facilities, services and support are required, such as in-home support, respite care and support to carers.

Survey of Disability, Ageing and Carers (SDAC)

The SDAC is the most detailed and comprehensive source of Australian disability data. It is the recommended source of data for providing accurate disability prevalence rates and is designed to measure and provide data on the entire spectrum of disability. The SDAC has been developed to align with international measures of disability as described in the International Classification of Functioning, Disability and Health (ICF). The large number of questions in the SDAC to assess disability levels limits the time available to ask respondents additional questions about the social and economic context of their lives. Therefore, we use the information collected in the Census to provide some of this context for people with a core activity need for assistance.

Short Disability Module

We also collect disability information in a number of our social surveys through the ‘short disability module’ – a set of sixteen questions designed to measure the frequency of disability. While the short disability module is not as effective as the SDAC in identifying disability (and therefore not recommended for prevalence) it does provide useful information about the characteristics of people with disability relative to those without. The module provides this information across a range of social dimensions such as health, income and housing, depending on the survey in which it is included. Information on the disability measure output from the short disability module can be found in ABS Sources of Disability Information.

Together, the SDAC, the Census and surveys which include the Short Disability Module help build the picture of disability in Australia. Comparisons of the three sources are outlined below.

Comparison of the Census, SDAC and Short Disability Module 
 Census of Population and HousingSurvey of Disability, Ageing and CarersShort Disability Module

Measures the number and key characteristics of people in Australia on Census Night, including where people live, age and sex, ethnicity, income, education, and living and housing arrangements.
Provides a snapshot of the economic, social and cultural make-up of Australia.

The most detailed and comprehensive source of Australian disability data.
The recommended source for providing measures of the prevalence of disability in Australia.

Used to identify the frequency of disability in a range of ABS social surveys including:
- National Health Survey
- Personal Safety Survey
- National Aboriginal and Torres Strait Islander Social Survey
- National Aboriginal and Torres Strait Islander Health Survey
- General Social Survey
- Survey of Income and Housing

ScopePersons usually resident in Australia and present in Australia on Census Night

Detailed information is collected about people with disability, older people (aged 65 years and over) and carers of people with disability, a long-term health condition, or older people.

A small amount of information is also collected about people not in these populations, so the demographic and socio-economic characteristics of the three target populations can be compared with the general population.

Includes people in urban and rural areas in all states and territories, living in either:
- Private dwellings and self-care retirement villages; or
- Health establishments that provide long-term cared accommodation (for at least three months).

Excludes people living in:
- Very remote areas of Australia
- Discrete Aboriginal and Torres Strait Islander communities
- Gaols or correctional institutions
- Other non-private dwellings such as hotels and motels, hostels, boarding houses or other long-term accommodation

See scope of relevant survey

Conducted every 5 years

Most recent Census: 2021
Next Census: planned for 2026

Every 3 to 6 years

Most recent SDAC: 2018
Next SDAC: 2022

Differs by survey

Most forms were self-completed online or using a paper form.
Interviewer assistance was available for people experiencing homelessness or living in remote areas.

The last SDAC was conducted by personal visits to households.
Paper forms completed by establishments that provide long-term cared accommodation (for at least three months).

Differs by survey
Questions collecting disability information

A set of four questions to derive ‘core activity need for assistance’.
The first three questions establish if the person ever needs assistance with one or more of the core activities (self-care, mobility and/or communication).
A fourth question establishes if the reason for need for assistance is due to a long-term health condition (lasting 6 months or more), disability (lasting 6 months or more) or the effects of old age.
A copy of the questions asked in the 2021 Census can be found in Core activity need for assistance (ASSNP) in the 2021 Census dictionary.

A large, specialist survey using detailed interviewer administered questions. The SDAC uses over 160 questions just to determine whether a person has a disability.
Information collected includes identification of disability, its underlying conditions, consequent levels of severity of restriction, participation in education, employment and community services and on the need for, and receipt of, assistance (extended to cover older people without a disability).
A copy of the questions asked in the 2018 SDAC can be found in the Survey material section of the Disability, Ageing and Carers, Australia: Summary of Findings publication.

A module with 16 questions and a series of prompt cards.
Applies similar criteria as the SDAC (but in a much briefer question format) to identify people with a disability and determine their severity of restriction.


Detailed demographic and socio-economic characteristics of those with a core activity need for assistance, including geographic distribution:
- Identification of small sub-populations that may be at higher risk of need for assistance with core activities
- Comparison of Indigenous and non-Indigenous population
- Analysis of characteristics of people living in very remote areas of Australia

Provides a reliable measure of national disability prevalence.
Provides in-depth information about the details of a person’s disability including: underlying conditions, severity of limitations/restrictions, the activities they require support with and the supports they receive.
Provides information about people with disability and older people’s need for/receipt of assistance with activities, allowing for a measure of ‘unmet need’ - important for the planning and provision of relevant disability and aged care services.

Inclusion in ABS social surveys, allows analysis of the different social characteristics and circumstances of people with disability relative to those without disability.
Provides insights into aspects of life/social dimensions other than those included in the SDAC and the Census


ABS sources on Disability data

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