Washington Group on Disability Statistics

Rationale for the Short Set

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Statement of rationale for the Washington Group general measure on disability

Disability as an umbrella term refers to problems, such as impairment, activity limitation or participation restrictions that indicate the negative aspects of functioning. While it is important to collect information on all aspects of the disablement process, it is not possible to do so in censuses or surveys not dedicated to disability. However, important information on selected aspects of disability can be obtained from censuses.

In their ongoing deliberations, the Washington Group (WG) has agreed that measurement of disability is associated with a variety of purposes which relate to different dimensions of disability or different conceptual components of disability models. A fundamental agreement of the WG was the need for a clear link between the purpose of measurement and the operationalization of indicators of disability. Equalization of opportunities was agreed upon and selected as the purpose for the development of an internationally comparable general disability measure. This purpose was chosen because:

1. It was relevant (of high importance across countries with respect to policy), and;
2. It was feasible (it is possible to collect the proposed information using a comparable general disability measure that includes a small set of 6 census-like questions).

In order to address this purpose, we begin by identifying persons who are at greater risk than the general population of experiencing restrictions in performing tasks (such as activities of daily living) or participating in roles (such as working). Measurements intended to identify this 'at risk' population represent the most basic end of the spectrum of activities (i.e. functional activities such as walking, remembering, seeing, hearing).This 'at risk' group would include persons with limitations in basic activities who may or may not also experience limitations in more complex activities and/or restrictions in participation depending in some instances on whether or not they use assistive devices, have a supportive environment or have plentiful resources.

Based on these decisions, the Washington Group has developed this question set for use on national Censuses for gathering information about limitations in basic activity functioning among national populations. The questions were designed to provide comparable data cross-nationally for populations living in a great variety of cultures with varying economic resources. The objective was to identify persons with similar types and levels of limitations in basic activity functioning regardless of nationality or culture. It was not our purpose to identify every person with a disability within every community. We recognize that this may not meet all the needs for disability statistics, nor will it replicate a population evaluated across a wider range of domains that would be possible in other forms of data collection or in administrative data.

The census format requires that a limited number of questions be devoted to any one statistic that needs to be produced. For the reasons of simplicity, brevity and comparability, the choice was made to identify limitations in domains of basic activity functioning that are found universally, which are most closely associated with social exclusion, and which occur most frequently. The information that results from the use of these questions is expected to:

1. Represent the majority, but not all persons with limitation in basic activity functioning in any one nation.
2. Represent the most commonly occurring limitations in basic activity functioning within any country.
3. Capture persons with similar problems across countries.

The proposed questions identify the population with functional limitations that have the potential to limit independent participation in society. The intended use of this data would compare levels of participation in employment, education, or family life for those with disability versus those without disability to see if persons with disability have achieved social inclusion. In addition the data could be used to monitor prevalence trends for persons with limitations in the particular basic activity domains. It would not represent the total population with limitations nor would it necessarily represent the 'true' population with disability which would require measuring limitation in all domains and which would require a much more extensive set of questions.