ABS Sources of Disability Statistics, 2018 - 2023

The ABS first collected disability information in a Monthly Population Survey (MPS) supplementary survey in 1967, and twice more as a MPS supplementary survey through the 1970s. It was later collected in a series of Special Supplementary Surveys in 1981, 1988, 1993, 1998 and 2003, expanding its populations of interest in 1988 to include older people and primary carers. The ABS has run the SDAC under its current name since 1993. Criteria for identifying disability were changed in the 1998 and 2003 surveys following consultation with users.

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 the International Classification of Functioning, Disability and Health (ICF). In SDAC, a person is considered to have disability if they have any limitation, restriction or impairment which restricts everyday activities and has lasted, or is likely to last, for six months or more. 

The SDAC has more than 160 questions to capture disability and, of all ABS surveys that include disability, is able to differentiate most effectively between people with disability and people with a long-term health condition without disability. The SDAC is designed to provide a wealth of detail on: 

• the identification of disability and its underlying conditions
• levels of severity of restriction
• participation in education, employment and community
• the need for, and receipt of, assistance (data on which is also collected for older people without disability).

The SDAC also identifies carers, the nature of their role, their access to support and the impact of the caring role on their employment and social participation.

The survey is enumerated in private dwellings using a household questionnaire, and selected non-private dwellings using an establishment questionnaire. The establishment questionnaire is used to collect information in cared-accommodation such as nursing homes. This is to ensure broad coverage of people with disability regardless of their living arrangements. 

Details of the methodology are available from the latest release page, available here Disability, Ageing and Carers, Australia: Summary of Findings | Australian Bureau of Statistics

Recommended uses:

• The SDAC is the recommended source for disability prevalence in Australia.
• The SDAC surveys people of all ages and is recommended for looking at characteristics of children and young people with disability, and families with a person with disability.
• The SDAC is recommended for looking at the characteristics of carers of people with disability and how much care they provide.

Limitations:

• While it provides reliable national prevalence data, the SDAC may be unreliable for small geographic areas or highly disaggregated data. In 2022, the SDAC surveyed 13,700 households around Australia and 1,100 establishments that provided cared-accommodation. This resulted in data on 33,764 people. To make this data representative of Australia as a whole, each person’s data was weighted (i.e. used to represent a certain number of people within Australia). Weighting introduces sample error into data results, making results with smaller sample sizes less reliable. Further details are available in the SDAC methodology.
• The SDAC does not survey people living in Very Remote geographical areas.
• The SDAC does not survey people living in discrete Aboriginal and Torres Strait Islander communities. Data about Aboriginal and Torres Strait Islander peoples from the survey must be used with careful consideration of the geographical limitations and the cultural and social factors that influence how a person may respond to the survey. 

Many ABS surveys collect disability information through the ‘Short Disability Module’ (SDM) – a set of 10 questions to determine if a respondent has disability, the severity (or level) of their disability (known as disability status) and their disability group/s (or broad type). 

In the SDM, a person is considered to have disability if they have at least one restrictive condition, they are restricted in everyday activities because of this condition, and the restrictive condition has lasted, or is likely to last, for six months or more. The SDM questions present lists of conditions for people to choose from, including an ‘any other long-term health condition’ option. For some conditions, respondents are specifically asked whether they are restricted by the condition, while other conditions are assumed to be restrictive. The SDM definition of disability is comparable to the SDAC definition. Both are conceptually aligned to the ICF. Questions in the SDM are summarised versions of questions in the SDAC. 

From 2018 to 2023 the following ABS surveys included the SDM:

• Survey of Income and Housing (SIH)
• General Social Survey (GSS)
• National Health Survey (NHS)
• Personal Safety Survey (PSS)
• Time Use Survey (TUS)
• National Aboriginal and Torres Strait Islander Health Survey (NATSIHS)
• National Aboriginal and Torres Strait Islander Nutrition and Physical Activity Survey (NATSINPAS).

The SDM was designed to allow broad comparative analysis between people with and without disability in surveys that focus on topics such as health, social participation, housing and income. The SDM was not designed to produce prevalence rates for disability. 

The current SDM questions are available in the Appendix. Some surveys may have slight changes in the way these questions are presented and worded, depending on how each survey is collected (online, in-person or through a telephone interview).

Between 2018 and 2023, surveys using the SDM provided information about people with and without disability, including:

• health conditions
• health characteristics of Aboriginal and Torres Strait Islander peoples
• housing circumstances
• experiences of personal safety
• social participation.

Recommended uses:

• The SDM is a shorter question module that can be inserted in a range of household surveys and run more frequently than the SDAC.
• The SDM supports analysis of disability as a characteristic in household surveys covering a range of topics.

Limitations:

• The SDM does not assess a respondent’s restrictions, limitations and impairments as thoroughly as SDAC. It is designed to collect information about disability as a broad characteristic rather than for prevalence. For this reason, it is not recommended to be used for reporting disability prevalence.
• Surveys using the SDM do not always include people under the age of 15 years so may not be suitable for comparing data on children with and without disability.
• Surveys using the SDM do not include people living in cared-accommodation and as a result will miss a significant proportion of older people with disability.
• Each household survey is designed to meet specific data needs. There will be differences between household surveys in sample size, question order, age coverage and geographical coverage that should be considered when using the SDM data.

The Census of Population and Housing (Census) measures the number and key characteristics of everyone in Australia on Census night. The Census provides a wealth of socio-demographic information because it counts every person and household in Australia. 

The Census collects information on whether a person has a need for assistance with core activities due to a long-term health condition, disability or old age. Core activities are defined as those which are essential to everyday living: self-care, mobility and communication. The Census core activity ‘need for assistance’ measure is conceptually comparable to the SDAC concept of 'profound or severe core activity limitation'. It was designed to provide population counts throughout Australia (including for small geographic areas) of people with the greatest need for assistance.

In the Census, people are asked the reasons for the need for assistance or supervision. While ‘Disability (lasting 6 months or more)’ is a reason, ‘old or young age’ is also a reason and it is possible that someone could select either or both reasons for requiring assistance.

More information about the Census need for assistance topic, including the Census questions, are available here: Disability and carers: Census, 2021

Recommended uses:

• The Census provides characteristics of all people (including children) throughout Australia. It provides information on people with the highest need for assistance (comparable to profound/severe disability in the SDAC), including in small geographic areas and in smaller government service regions, which is essential for service planning.

Limitations:

• The Census does not capture people with moderate disability, mild disability or people with disability who do not require assistance with activities of daily living.
• The Census questions ask about a person’s need for assistance and the broad reason for the need for assistance. Detailed information about a respondent’s restrictions, limitations and impairments is not collected. For example, a person’s need for assistance in the Census may be due to age rather than disability. Census data is therefore not recommended for reporting disability prevalence in Australia.

The following table shows disability prevalence for the SDAC and selected surveys using the SDM between 2018 and 2023. Data for all ABS surveys that had questions on disability between 2018 and 2023, including measurements of error, is available in the data downloads.

What the data shows

As seen in this table, surveys using the SDM show generally higher rates of disability than the SDAC.

How to interpret this 

• In the SDAC, a respondent is asked comprehensive questions about any long-term limitations, restrictions or impairments. If they have indicated limitations, restrictions or impairments, the SDAC then does a thorough assessment of whether any of these restrictions affect a person's core, education or employment activities.
• In the SDM, a respondent is asked if they have any long-term health conditions, from two multiple-choice picklists. For some conditions, respondents are specifically asked whether they are restricted in everyday activities by the condition, while other conditions are assumed to be restrictive (eg. hearing loss). Unlike the SDM, the SDAC does not necessarily assume conditions are restrictive. The extra detail gathered about a person’s limitations and restrictions in the SDAC enables more refinement of whether someone is restricted or not by their condition, and therefore whether they have disability or not. It is much more likely for the SDM to group people with disabling and non-disabling long-term health conditions into the ‘with disability’ category than the SDAC. Additionally, there are some types of long-term health conditions that the SDM differentiates much less effectively in terms of whether they are disabling vs non-disabling compared with the SDAC. For example, difficulties with hearing. These are discussed in more detail in the ‘Disability group’ section below.
• Surveys using the SDM show varying prevalence results. This shows that the SDM is good for comparisons of people with and without disability but the SDAC is best for prevalence. 

In ABS surveys, disability status (also called disability severity) is categorised into one of the following categories: 

• Profound - those who always need help with core activities of self-care, mobility and/or communication.
• Severe - those who sometimes need help with core activities of self-care, mobility and/or communication.
• Moderate - those who had difficulty with self-care, mobility, and communication tasks but did not require help.
• Mild - those who don’t have difficulty or need help but used aids for self-care, mobility, and communication tasks, or who were unable to do at least one mobility activity (for example easily walk 200 metres or walk up and down stairs without a handrail).
• Schooling or employment restriction only - restricted in schooling or employment such as requiring special equipment for education or employment, special tuition or time off school / work. Schooling restriction questions are asked only of those aged 5–20 years who attend school or do not attend due to disability. Employment restriction questions are asked of people aged 15 years and over.
• No specific limitation or restriction - those who indicated that they had a limitation or restriction but no difficulties with the core activities, additional mobility tasks, and school/study or work.

The following table shows disability status from selected ABS surveys between 2018 and 2023. Data for all ABS surveys that had questions on disability between 2018 and 2023, including measurements of error, is available in the data downloads.

This table and graph show that:

• The SDAC rate for the 'profound/severe' category is higher than for surveys using the SDM.
• The Census ‘need for assistance’ rate aligns best with the SDAC 'profound/severe' category compared with SDM rates.
• The SDAC has a markedly lower rate for ‘no specific limitation or restriction’ than the surveys using the SDM.
• The rate of ‘schooling / employment restriction only’ is lower in the SDAC compared to surveys using the SDM.

• The SDAC rate for the 'profound/severe' category is higher than for surveys using the SDM because of the greater detail collected in the SDAC about a person’s restrictions and limitations. The SDAC allows respondents more options to identify areas where they need assistance, therefore more opportunity to be grouped into this category. The large number of questions in the SDAC enables the screening out of people without disability more accurately, and also the identification of those people with a profound / severe disability more accurately, compared to the SDM. This means that, of people classified as having disability, more will be classified as having profound / severe disability in SDAC compared with the SDM. It follows from this that the SDM generally has higher numbers of people categorised into the other levels of disability severity compared to the SDAC.
• The Census ‘need for assistance’ measure aligns broadly with the SDAC 'profound / severe' measure. The Census counts people in establishments, like the SDAC. Surveys using the SDM do not obtain establishment data so do not survey people with some of the most severe disability. As a result, these surveys will show lower proportions of people with profound or severe disability. If data from people living in establishments was excluded from the Census results, the 'need for assistance' rate for people aged 18 and over would decrease from 6.4% to 5.7%. In the SDAC, excluding those living in establishments would drop the profound / severe disability rate for people aged 18 and over from 8.4% to 7.6%.
• In the SDM, respondents who have disability, but who do not have moderate, severe or profound disability, are asked whether they use aids to assist with tasks and how easily they can do mobility activities such as walking 200 metres, negotiating stairs, bending to pick up objects or using public transport. If they use aids or have difficulty with any of these tasks, they meet the criteria for mild disability. If not, they are screened for any education and/or employment restrictions. The presence of an education and/or employment restriction can mean they meet the criteria for ‘schooling and/or employment restriction only’. Otherwise, they are categorised as having ‘no specific limitation or restriction’.
• The higher rates of ‘schooling / employment restriction only’ and ‘no specific limitation or restriction’ in the SDM may be due to the more general wording of questions in the SDM and the filtering process of the SDM questions. The SDM does not categorise people with mild disability as accurately as the SDAC, which means people who would have been classified as having a mild level of disability in the SDAC may be classified into a less restrictive severity category such as ‘schooling / employment restriction only’ or ‘no specific limitation or restriction’ in the SDM surveys.
• The much lower rate of ‘no specific limitation or restriction’ in the SDAC compared to surveys using the SDM is due to the large number of questions in the SDAC about the restrictive impact of conditions. Respondents have more opportunity to identify and label their restrictions within the SDAC. The focus of many questions in the SDAC is on how a person is impacted by a long-term health condition, rather than whether they simply have one. It is possible that many people who are identified in the SDM as having disability with ‘no specific limitation or restriction’ would not be considered to have disability as defined in the SDAC.

The SDAC and SDM questions allow for disability to be categorised into the following groups (or types): 

• Sensory and speech (for example loss of sight)
• Learning and understanding (for example difficulty learning or understanding things)
• Physical (for example difficulty gripping or holding things)
• Psychosocial (for example nervous or emotional condition, memory problems)
• Head injury, stroke or acquired brain injury
• Other (any other long-term conditions resulting in a restriction in everyday activities).

The following graph shows the proportion of respondents in each disability group for the SDAC and selected surveys using the SDM between 2018 – 2023. Further data from all ABS surveys including disability between 2018 and 2023, including measurements of error, is available in the data downloads.

• Results are generally comparable between the surveys.
• The greatest differences in disability group rates between the SDAC and surveys using the SDM is for the ‘sensory and speech’ and ‘physical restriction’ groups, where the SDAC proportions are generally lower. 

• The SDAC has more questions to evaluate sensory conditions than the SDM. An example of this is someone with hearing difficulties. In the SDAC they may not be categorised as having disability; however, in the SDM they may fall into the ‘no specific limitation or restriction’ category.
• Likewise, someone who said they had a condition that ‘restricts physical activity or physical work (for example back problems, migraines)’ in the SDM provides less information on the condition’s impact than they would in the SDAC. They would be screened into the ‘with disability’ category in the SDM, as this is pick-list option that, when chosen, automatically places someone in a disability category. In the SDAC they may not be classified as having disability because additional questions are asked about the condition’s restrictive impact. While the SDM data on a respondent’s disability group will be broadly accurate, the SDAC data is more accurate. 

The following table provides an overview of the recommended uses and limitations for disability statistics in ABS collections during the reference period 2018 to 2023. 

The Short Disability Module is available in Computer Assisted Personal Interview (CAPI), Computer Assisted Web Interview (CAWI) and Computer Assisted Telephone Interview (CATI) formats for household surveys.

The NATSIHS includes one additional question (not shown here), which asks respondents to state the main disability type if they reporting having more than one disability type.