Frequently Asked Questions

This module of six questions is best situated either at the beginning of a survey questionnaire (together with the demographic information collected on household family members) or towards the beginning of a section that deals with health information. It is recommended that the module not be added on at the end of the questionnaire.

Disability is not a Yes/No dichotomy but describes a dynamic and complex relationship between a person, the environment in which they live and their ability to participate in society on an equal basis with others.  The aspects of functioning that are captured by the six questions are also not dichotomies; functioning in each of these domains exists on a continuum.

A question with a Yes/No response option forces the person answering to self-identify as having the difficulty or not. It is better to offer a range of responses as in the WG questions. The four answer categories recommended by the WG describe a continuum of functioning from: no difficulty to cannot do at all. The continuum can be visualized like this:

The distribution above creates four points equally distributed among the continuum that allows respondents to easily discriminate among options. The recommended cut-off (at a lot of difficulty) identifies those with the intended level of difficulties. 

‘Disability’ is a word whose meaning can vary not only across cultures but among people in the same culture.  Moreover, in some cultures the term is associated with shame and/or stigma. In order to avoid casting the questions in a negative frame or light and to reduce response variability due to differential understanding of the term, more neutral language needs to be used.  In addition, rather than ask directly about disability per se, the focus of the questions is on functioning. The domains of functioning covered are both basic and universal; they are common to all countries and cultures and evidence has shown that they are recognized by people in different languages.  The use of the term disability in the questionnaire or in interaction between the interviewer/enumerator and the respondent will reintroduce variability in how the term is understood including introducing stigma and can reduce or eliminate the validity of the questions set.

Three main purposes for the collection of disability data have been identified:

1. Monitor the Population: to understand the scope of disability in a population for evaluating policies and interventions designed to address disability in the population.
2. Service Provision: seeks to identify those with specific needs in order that services are designed and implemented to meet those needs. Interventions might be general – servicing the entire population (i.e., universal design), or specific - targeted for people more specific needs (e.g., wheelchair users). Addressing service provision requires more extensive information than monitoring the functioning of the population, and cannot be served by censuses.
3. Equalization of Opportunities: assesses whether persons with disability are participating in social and economic life at the same level  as persons without disability, This is accomplished by disaggregating population data by disability status to determine if important outcomes (e.g., access to education and employment) are different for people with disabilities compared to their non-disabled peers.

The Washington Group (WG) on Disability Statistics is a United Nations Statistics Commission City Group formed of representatives of National Statistical Offices (NSOs) working on developing methods to improve statistics on persons with disabilities globally. In this work, NSOs (currently over 135) are joined by various international agencies and experts including UN agencies (e.g., UNICEF, ILO, World Bank), bilateral aid agencies (e.g. DFID, DFAT, USAID), NGOs (e.g., Humanity & Inclusion, Sightsavers), Disabled People Organizations (DPOs), and researchers.

The United National Statistical Commission authorized the formation of the WG to address methodological issues that were identified at the International Seminar on Measurement of Disability in New York in June 2001. The consensus of that seminar was the recognition that statistical and methodological work was needed at an international level in order to facilitate the comparison of data on disability cross-nationally.

The WG, like all City Groups, invites representatives from all national statistical agencies to come together and participate in addressing the statistical challenges to collecting valid, reliable and cross-nationally comparable data on disability.

While the key informant method may identify some people with disabilities, particularly those with more obvious types of impairment, assessing functioning of individuals through observation or assumed knowledge of individuals is subjective and can be very inaccurate.

This method might be appropriate in some situations if programs are interested in getting a preliminary count of the number of persons with functional limitations in area of interest.  It must be understood that the estimates will likely be an underestimate but it will be difficult to determine the magnitude of the underestimate. This method also doesn’t allow for disaggregation of by disability and other characteristics (i.e. age, gender).  This approach could be seen as a first step to be followed up by a broader data collection at the individual level such as using the WG Short Set on a representative sample of the community (e.g. one in ten households, or one in five people at a community event).

In some data collection efforts, key informants used tend to come from the membership of Disabled People Organizations because they are easy to locate. It should be kept in mind that this is not a representative group. They tend to be more knowledgeable and have greater access to services.

Using the key informant method to identify people with disabilities for services will likely miss many persons with disabilities who could be program participants.

The WG question sets have been carefully developed and tested and should be used without any changes to the wording of questions, order of questions, response categories, and cut-off points for classification of disability. Extensive testing and experience in a variety of contexts has demonstrated that making changes to the questions in an attempt to ‘improve’ them tends to have unforeseen consequences in terms of reducing accuracy. Using the questions as developed also allows for comparability of data across communities within countries or internationally among countries.

A possible exception to the ‘no change’ rule is if pre-testing highlights aspects of the questions that are not relevant or confusing in particular contexts. For example, in Bangladesh it was observed that hearing aids are for the most part non-existent. In this situation the removal of reference to the use of hearing aids in the hearing question was permitted. If in any doubt, it is best to contact the WG Secretariat and ask about the implications of any adaptations.

If additional information on functioning or health conditions is required, these questions should be added following the WG questions – not before. It is important to maintain the integrity of the WG questions. 

The short intro to the question set was developed given the census context where questions cover many disparate areas.  The introductory sentence ‘The next questions ask about difficulties you may have doing certain activities because of a HEALTH PROBLEM’ was included as a way of transitioning from one section of the questionnaire to another. Programs may choose not to use this introductory sentence, but it is important to not replace this with a sentence that uses the term ‘disability’. The WG-SS has deliberately been developed to focus attention on functioning – using neutral language and does not use the term ‘disability’.

Reporting of results using the WG questions should clearly state how the questions were used, the age range of participants and the cut-off points used to determine disability status. To allow comparison of data cross-nationally, the WG recommends that those who respond to at least one of the six questions with a lot of difficulty or cannot do at all be considered as with disability.

The WG-SS questions were originally developed for censuses and large population-based surveys.

The WG-SS was designed as a core set of questions for self- or proxy-reporting of functional limitations at the individual level. Although they were developed to be appropriate for administration as part of a census, the questions can be included in any existing data collection activity within a program-level monitoring and evaluation framework or can be incorporated into smaller-scale surveys that collect data at the individual level.

The WG-SS is designed to avoid some of the failures of earlier ways of operationalizing disability (e.g. using only one question or a screening question such as ‘Do you have a disability?’).

As they were developed for use in censuses, the questions are as succinct and straightforward as possible without compromising their effectivity in the disaggregation of outcome data, for example, access to education or employment by disability status. Disaggregation allows for the determination of whether persons with disability have achieved the same level of participation as those without a disability on the selected outcome indicators.

In order to monitor compliance with the UN Convention on the Rights of Persons with Disability (CRPD) or evaluate whether programs are including people with disabilities and meeting their needs, baseline data on disability status collected at the individual level and follow-up data are required.  Conducting surveys that include the WG-SS at a minimum of two key points in a program (e.g. start and end) will provide valuable information on how people with disabilities have benefited from or been included in a program. These do not have to be large-scale surveys, which may be beyond the resources of a program. In many cases it will be possible to include the questions into the program’s usual data collection processes. Care should be taken to train enumerators to properly ask the questions. Sample sizes should be large enough so that information on the population with disabilities served by the program can be described.

• Where more detailed information is required, the WG Extended Set of questions (WG-ES) can be used.
• The WG-ES includes information on upper body functioning; psychosocial difficulties (anxiety and depression); pain and fatigue; and the additional information in certain domains of functioning both with and without the use of assistive technology/aids.

• The WG-SS will identify most, but not all, people with disabilities
• WG-SS questions were not designed to measure all aspects of difficulty functioning that people may experience, but rather those domains of functioning that are likely to identify a majority of people at risk of participation restrictions. These include difficulties seeing, hearing, walking or climbing stairs, remembering or concentrating, with self-care, and difficulty communicating.
• Those with psychosocial difficulties that do not impact cognition, communication or self-care will be under-reported. This issue is addressed in the extended set.

• In order to collect internationally comparable data, it is important that the WG question be used without any changes to the wording of questions, order of questions, response categories, and cut-off points for classification of disability.
• There are very limited exceptions to this rule. For example, in countries where hearing aids are not available, leaving the hearing aid clause off the hearing question is allowed.
• Before making any modification consult the WG secretariat. Often the issues that arise in adapting to a particular country context can be addressed in how the questions are translated.
• Detailed information about this topic can be found in the translation FAQ page, but if you have any doubt please get in touch with the Secretariat for advice.