1200.0.55.001 - Disability Variables, 2006  
ARCHIVED ISSUE Released at 11:30 AM (CANBERRA TIME) 03/10/2006  First Issue
   Page tools: Print Print Page Print all pages in this productPrint All  
Contents >> SEVERITY OF DISABILITY >> Underlying Concepts


Name of the variable

5. The name of the variable is 'Severity of disability'.

6. This variable has been developed as an indicator of the existence of a person's disability, and the severity of that disability. Further, it can be used to determine if the person has the relatable Census concept 'Core activity need for assistance'.


Nominal definition

7. The variable 'Severity of disability' is defined as:

  • the level of restriction a person has in undertaking core and education/employment activity.

8. 'Severity of disability' is an attribute of the counting unit Person.

Operational definition

9. Operationally, 'Severity of disability' is defined as the extent to which a person's activity is limited by a condition lasting or likely to last six months or more. It is obtained by coding of responses to a series of direct questions. In most circumstances the result obtained is dependent on respondent perception of their need for help, and the meanings of 'help', 'supervision', 'difficulty', 'restriction', and 'everyday activity'.

Scope of the variable

10. The variable 'Severity of disability' applies to all Persons.


11. 'Severity of disability' requires the supporting variable 'Age'. This is necessary to sequence persons aged 65 years or more past the final questions of the Disability Module on education and employment difficulties.


12. Extensive ABS testing has shown that disability is a difficult and complex concept to measure, particularly with a short question module. Also, there are quality limitations with any measurement tool and the Disability Module is no exception. The disability population identified via the Disability Module is larger than the population that would be obtained from the same sample using the full SDAC question set because SDAC includes a number of screening questions aimed at eliminating false positive responses. The standard Disability Module is designed to obtain data on the broad characteristics of the disability population in the particular survey in which the module is included, rather than producing the detailed disability data or national prevalence estimates derived from SDAC.

13. There are a number of reasons why data on disability is difficult to collect with a great degree of accuracy. These include:
  • individual perceptions of disability, ie the relative effect on a respondent of both positive and negative factors (such as energy levels, optimism, pain or depression) at the precise time of the survey;
  • different cultural concepts of what constitutes disability;
  • sensitivity aspects of disability, ie the willingness or ability of the respondent to report conditions such as alcohol and drug-related conditions, schizophrenia, mental retardation or mental degeneration;
  • the episodic and seasonal nature of some forms of disability, ie conditions which are episodic or affected by seasonal changes (e.g. epilepsy, asthma) and may not be apparent at the time of interview and are therefore not reported;
  • under-reporting, ie the need for help may be underestimated due to pride, or as help has always been received, or due to such adjustment to life with a disability that consciousness of an inability to perform a particular task no longer exists; and
  • inconsistency in benchmarks, ie the criteria by which people assess the difficulty of performing tasks may vary depending on whether it is compared with others of a similar age or with the person's own ability when the person was younger.

14. To fully derive 'Severity of disability' the additional variable 'Age' is required. Responses to 'Age' serve as a filter for some individual questions in the standard question module. The method by which 'Severity of disability' uses the variable 'Age' is explained in the Derivation procedures section.

Previous PageNext Page