Disaggregation by Disability: A way forward

In this article, Mitchell Loeb, a Health Scientist in the Office of Analysis and Epidemiology at the National Center for Health Statistics (NCHS), Centers for Disease Control and Prevention, USA, who is also involved in the work of the Washington Group on Disability Statistics gives an overview of the progress made with the Washington Group Questions.

Conditions to disaggregate data by disability

There are two necessary conditions that must be met in order to disaggregate data by disability. First, the indicator must already be collected and second, there must be a straightforward and simple way to identify persons with disabilities so that the indicator can be disaggregated by disability status.

The current Sustainable Development Goals (SDGs) framework addresses the first condition, as the agreed set of indicators will be used for monitoring and evaluating progress in the implementation of the SDG goals and targets. The second condition has also been met through the establishment of the Washington Group on Disability Statistics (WG). Established in 2002 under the auspices of the UN Statistical Commission, the group – with membership from over 100 national statistical offices – has developed a set of six questions that can identify persons with disabilities for disaggregation purposes in an internationally comparable way. The 6 question set has been recommended by the UN for use in the next round of population censuses, and a UN sponsored Disability Data Expert Group has recommended them for use in disaggregating the SDGs and also for monitoring the implementation of the UN Convention on the Rights of Persons with Disabilities (UNCRPD). Countries in the Asia and Pacific Region, through the United Nations Economic and Social Commission for Asia and the Pacific (UNESCAP), have recommended their use in producing the Incheon “Making the Right Real” Disability Strategy indicators.  Bilateral agencies have also adopted them. For example, both DFID (UK Department for International Development) and DFAT (Australian Department of Foreign Affairs and Trade) have decided to use the questions for monitoring the effectiveness of their programs in reaching persons with disabilities. Overall, there is a broad international consensus that the WG Questions represent the international best practice for disaggregating data by disability.

The WG Short Set of questions are well suited for disaggregating data by disability for the international monitoring of inclusion. These questions are designed to identify those at greater risk than the general population for participation restrictions due to difficulties in six core functional domains, if appropriate accommodations are not made.  The questions focus on difficulty performing basic activities (walking, seeing, hearing, cognition, self-care and communication). Originally designed for data collection in a census format, the focus on functioning and the brevity of the tool allow it to be easily integrated into larger survey applications. 
The WG Short Set does not identify particular health conditions or diagnostic categories but rather captures the possible impact of these conditions on functioning in 6 domains.  Disability is a complex process, and no short set of questions can measure all aspects of difficulty functioning that people may experience.  The six domains included in the WG question set were selected because they are likely to identify a most people at risk of participation restrictions. The WG Short Set questions represent the component of disability that focuses on activity limitations, that, in conjunction with other modules on, for example, the environment and participation, fulfils the ICF (International Classification of Functioning, Disability and Health) bio-psychosocial model of disability.

The WG Short Set by itself only provides information on disability status but the set was designed to be used in conjunction with other survey tools, i.e. demographic and health surveys, household income and expenditure surveys, living standard surveys, to enable disaggregation of key indicators from these indicators such as employment status and educational attainment, by disability status.

The Washington Group Short Set of Questions on Disability

1. Do you have difficulty seeing, even if wearing glasses?
2. Do you have difficulty hearing, even if using a hearing aid?
3. Do you have difficulty walking or climbing steps?
4. Do you have difficulty remembering or concentrating?
5. Do you have difficulty (with self-care such as) washing all over or dressing?
6. Using your usual language, do you have difficulty communicating, for example understanding or being understood?

Each question has four response categories: (1) No, no difficulty, (2) Yes, some difficulty, (3) Yes, a lot of difficulty and (4) Cannot do it at all.  The WG question response categories capture a range of severity in the difficulty experienced. Multiple disability scenarios can be described depending on the domain(s) of interest and the choice of severity cut-off. There is more than one way to capture disability through the application of this set of core questions; resulting in not one but several possible population prevalence estimates that will vary in both size and in composition of the group identified as having a disability.

The WG recommends that the following cut-off for defining the populations with and without disabilities for the purpose of computing prevalence and differentials in participation for international reporting and cross-national comparability: 

The sub-population disabled includes everyone with at least one domain that is coded as a lot of difficulty or cannot do it at all.

Countries using the WG short set of questions should not feel restricted to only producing data based on the above cut-off. Data can be presented by individual domains of functioning, and at several levels of severity from very mild (some difficulty) to very severe (unable to do at all). For example, discovering that in rural regions of the country participation restrictions tend occur at lower levels of activity limitations than in urban areas could be suggestive that barriers to participation are more significant in areas with poorer infrastructure.

How to use the Short Set to disaggregate data by disability status

Collecting data using the WG Short Set will provide valuable insight into whether people with disabilities are benefitting from policies and programs designed to improve participation. The disaggregated data can be used to evaluate these programs and policies whether they are overarching, such as the passage of laws or regulations that target all people, or can community based targeting a specific population subgroup. The questions can be asked at several points in time to see if progress has been made during an intervention period to ascertain if people with disabilities are being included or left behind. The questions can be added to large-scale surveys but can also be added to smaller scale surveys or can be included into ta program’s usual management/monitoring and data collection processes. For example, the questions could be used in an existing employment survey to determine the percentage of persons with disability who are unemployed in comparison to the percentage of people without a disability who are unemployed or can be asked as part of an intake form for those seeking non-disability related services to see if the service is being accessed by persons with disability to the same extent as it is by persons without disability. As a group they can be administered in just over one minute, which does not impose a significant burden on existing instruments.
 

Why is this important?

Understanding the exact nature of the barriers faced by persons with disabilities and determining the actions necessary to equalize participation requires the collection of extensive and detailed information. Disaggregating outcome indicators, such as the SDGs, or programmatic objectives, to determine if gaps exist between those with and without a disability is a necessary first step towards addressing disparities. Doing so only requires the addition of a small set of questions on already existing data instruments.

The importance of disaggregation can be illustrated by an example in the area of education. In recent years the rate of primary education has increased significantly, in no small part from efforts to build more schools and train more teachers. A logical conclusion would be that to address those last few percent of children not in school, a country should simply build even more schools and train more teachers according to past models. But if the remaining out-of-school children are out of school for reasons associated with other characteristics – such as disability – then only doing what has been done in the past may not get a country that much closer to universal primary education. It may require different actions, like making schools, school materials and curricula more accessible.  If school enrolment was not disaggregated by disability status, we would not know that children with disability were not attending school at the same rate as those without disability – and interventions would not be initiated to address this disparity.

For more information please refer to the Washington Group website