Question Types Explained
The methods used for identifying people with disabilities differ across surveys, so it is important when reporting on the prevalence of disability to take note of the methodology.
The data sets in use on the portal use one of five question type methodologies:
- Question Type 1: used a question such as “Do you have a disability?”
- Question Type 2: used a list of medical conditions
- Question Type 3: used functional difficulty questions
- Question Type 4: used adapted Washington Group Questions
- Question Type 5: used Washington Group Questions as recommended
The Data Source and Methodology by Country table provides reported prevalence in the selected countries based on the methodology used.
The first group of countries use a question such as “Do you have a disability?” (Question Type 1). This leads to underreporting for a few reasons: (1) the term disability is usually associated with shame, (2) people tend to think of disability as something severe, so more moderate conditions are missed, and (3) older people often associate functional limitations with age which they consider different from “disability” (Ingstad and Whyte 1995; Mont 2007).
The second group of countries use a list of medical conditions (Question Type 2). This method is often not considered good practice. Firstly, not all medical conditions can be included in any list, and secondly, people with less education and/or access to medical care may not know their diagnosis (Palmer and Harley 2011). But more importantly, a medical diagnosis does not provide accurate information on a person’s ability to function; two people with the same diagnosis may have very different levels of difficulty doing basic activities (Mont 2007; Van-Brakel and Officer 2008; Miller 2006).
Asking about functional limitations – that is, difficulty doing basic activities – is the preferred approach, such as asking if they have difficulty walking or climbing steps. There may be many medical reasons – but a functional question addresses what a person can or cannot do, not the reason they cannot do it. The third group in the table (Question Type 3) takes such an approach but uses questions other than The Washington Group Questions. For example the Senegalese DHS asks a question on whether somebody has difficulty relating to others. The fourth group attempts to use the Washington Group questions, but adapts them in some ways that are not recommended (Question Type 4). For example, changing the scaled responses to yes/no responses, adding an introduction that uses the term “disability”, or even asking a screener question, such as “Do you have a disability?”, that then leads to the Washington Group questions if the respondent answers in the affirmative. All of these adaptations undermine the recommended approach.
Countries listed under the final category report that they have used the Washington Group questions as recommended (Question Type 5). However, from the Washington Group’s experience of interacting with national statistical offices that have been using the questions, we know that some countries make verbal reference to “disability” in an introductory statement which, again, undermines the approach. In other instances they may change the response categories from a scaled response to a yes/no response, which damages data validity. Or they may modify the wording in other ways. For example, Paraguay eliminated the self-care question (question 5 of the short set). However, they then tried to capture people with upper mobility issues that the question was identifying, added “moving one’s arms” to the walking question. In testing, the Washington Group found that providing even a short list of domains in a single question is often confusing for respondents.
Data Source and Methodology by Country
Country | Data Name | Data Year | Question Type | Question Type Detail |
Afghanistan | Living Conditions Survey (LCS) | 2016 | 5 | Used the Washington Group Questions as recommended |
Albania | Demographic Health Survey | 2008-2009 | 1 | Uses a question such as 'Do you have disability?' |
Bangladesh | Population & Housing Census | 2011 | 1 | Uses a question such as 'Do you have disability?' |
Bangladesh | Household Income and Expenditure Survey (HIES) | 2016 | 5 | Used the Washington Group Questions as recommended |
Botswana | Population and Housing Census | 2011 | 1 | Uses a question such as 'Do you have disability?' |
Burkina Faso | Recensement general de la population et de l'habitation | 2006 | 1 | Uses a question such as 'Do you have disability?' |
Burkina Faso | Demographic Health Survey | 2014 | 1 | Uses a question such as 'Do you have disability?' |
Cambodia | Demographic Health Survey | 2014 | 5 | Used the Washington Group Questions as recommended |
Cameroon | Demographic Health Survey | 2011 | 2 | Use a list of medical conditions |
Chad | Demographic Health Survey | 2014 | 2 | Use a list of medical conditions |
Colombia | Demographic Health Survey | 2015 | 4 | Used the Washington Group Questions in some way that is not recommended |
Costa Rica | X Censo Nacional de Población y VI de Vivienda | 2011 | 2 | Use a list of medical conditions |
Djibouti | Enquete Djiboutienne aupres des Menages (EDAM) | 2017 | 3 | Uses a question on functional limitations, i.e. what a person can or cannot do |
Dominican Republic | IX National Population and Housing Census | 2010 | 4 | Used the Washington Group Questions in some way that is not recommended |
Ecuador | VII Censo de Poblacion y VI de Vivienda | 2010 | 1 | Uses a question such as 'Do you have disability?' |
Egypt | Population, Housing and Establishments Census | 2006 | 2 | Use a list of medical conditions |
El Salvador | Population and Housing Census | 2007 | 3 | Uses a question on functional limitations, i.e. what a person can or cannot do |
Ethiopia | Population and Housing Census | 2007 | 3 | Uses a question on functional limitations, i.e. what a person can or cannot do |
Gambia | Demographic Health Survey | 2013 | 3 | Uses a question on functional limitations, i.e. what a person can or cannot do |
Gambia | Labor Force Survey (LFS) | 2018 | 5 | Used the Washington Group Questions as recommended |
Ghana | Population and Housing Census | 2010 | 1 | Uses a question such as 'Do you have disability?' |
Haiti | Demographic and Health Survey | 2016 | 5 | Used the Washington Group Questions as recommended |
India | Disabled people in India, a statistical profile | 2016 | 1 | Uses a question such as 'Do you have disability?' |
Indonesia | Population and Housing Census | 2010 | 3 | Uses a question on functional limitations, i.e. what a person can or cannot do |
Iraq | Population and Housing Census | 1997 | 1 | Uses a question such as 'Do you have disability?' |
Jordan | Population and Housing Census | 2004 | 1 | Uses a question such as 'Do you have disability?' |
Kenya | Population and Housing Census | 2009 | 1 | Uses a question such as 'Do you have disability?' |
Kiribati | Population and Housing Census | 2015 | 3 | Uses a question on functional limitations, i.e. what a person can or cannot do |
Liberia | Population and Housing Census | 2008 | 1 | Uses a question such as 'Do you have disability?' |
Liberia | Household Income and Expenditure Survey (HIES) | 2016 | 5 | Used the Washington Group Questions as recommended |
Malawi | Population and Housing Census | 2008 | 4 | Used the Washington Group Questions in some way that is not recommended |
Malawi | Third Integrated Household Survey (IHS) | 2010 | 5 | Used the Washington Group Questions as recommended |
Maldives | Demographic Health Survey | 2009 | 5 | Used the Washington Group Questions as recommended |
Mali | Fourth General Census of Population and Housing | 2009 | 2 | Use a list of medical conditions |
Mali | Demographic Health Survey | 2018 | 2 | Use a list of medical conditions |
Mauritania | Demographic Health Survey | 2000 | ||
Mexico | Population and Housing Census | 2010 | 3 | Uses a question on functional limitations, i.e. what a person can or cannot do |
Morocco | Population and Housing Census | 2014 | 3 | Uses a question on functional limitations, i.e. what a person can or cannot do |
Mozambique | III recenseamento geral da população e habitação | 2007 | 1 | Uses a question such as 'Do you have disability?' |
Myanmar | First Myanmar National Disability Survey | 2010 | 5 | Used the Washington Group Questions as recommended |
Namibia | Household Income and Expenditure Survey (HIES) | 2015 | 5 | Used the Washington Group Questions as recommended |
Niger | Demographic Health Survey | 2017 | ||
Nigeria | General Household Survey Panel (GHSP) | 2018 | 5 | Used the Washington Group Questions as recommended |
Nigeria | General Household Survey | 2012-2013 | ||
Pakistan | Situational Analysis and National Plan of Action for People with Disabilities prepared for the World Bank | 2004 | 1 | Uses a question such as 'Do you have disability?' |
Pakistan | Demographic and Health Survey | 2017 | 5 | Used the Washington Group Questions as recommended |
Panama | XI Censo Nacional de Población y VII de Vivienda | 2010 | 1 | Uses a question such as 'Do you have disability?' |
Papua New Guinea | Household Income and Expenditure Survey (HIES) | 2009 | 3 | Uses a question on functional limitations, i.e. what a person can or cannot do |
Philippines | Population and Housing Census | 2000 | 1 | Uses a question such as 'Do you have disability?' |
Rwanda | Integrated Household Living Conditions Survey 4 | 2010 | 2 | Use a list of medical conditions |
Rwanda | Labor Force Survey (LFS) | 2018 | 5 | Used the Washington Group Questions as recommended |
Saint Lucia | Central Statistical Office calculations | 2010 | 1 | Uses a question such as 'Do you have disability?' |
Senegal | Population and Housing Census | 2013 | 5 | Used the Washington Group Questions as recommended |
Senegal | Demographic Health Survey | 2014 | ||
Sierra Leone | Population and Housing Census | 2004 | 1 | Uses a question such as 'Do you have disability?' |
Sierra Leone | Demographic Health Survey | 2013-2019 | ||
South Africa | Census | 2011 | 5 | Used the Washington Group Questions as recommended |
South Africa | General Household Survey (GHS) | 2018 | 5 | Used the Washington Group Questions as recommended |
South Sudan | 5th Sudan Population and Housing Census | 2008 | 5 | Used the Washington Group Questions as recommended |
Suriname | Population and Housing Census | 2012 | 3 | Uses a question on functional limitations, i.e. what a person can or cannot do |
Tajikistan | Survey of Water, Sanitation, and Hygiene (WASH) | 2016 | 5 | Used the Washington Group Questions as recommended |
Tanzania | Population and Housing Census | 2012 | 5 | Used the Washington Group Questions as recommended |
Tanzania | National Panel Survey (NPS) | 2014 | 5 | Used the Washington Group Questions as recommended |
Timor-Leste | Demographic Health Survey | 2016 | 5 | Used the Washington Group Questions as recommended |
Tonga | Population and Housing Census | 2016 | 5 | Used the Washington Group Questions as recommended |
Trinidad and Tobago | Population and Housing Census | 2011 | 1 | Uses a question such as 'Do you have disability?' |
Uganda | National Panel Survey (NPS) | 2010 | 5 | Used the Washington Group Questions as recommended |
Uganda | Demographic Health Survey | 2016 | 5 | Used the Washington Group Questions as recommended |
United Kingdom | Papworth Trust, Facts and Figures: Disability in the United Kingdom | 2018 | 3 | Uses a question on functional limitations, i.e. what a person can or cannot do |
Uruguay | General Population Census VIII, Homes IV and Housing VI | 2011 | 4 | Used the Washington Group Questions in some way that is not recommended |
Vanuatu | Population and Housing Census | 2009 | 3 | Uses a question on functional limitations, i.e. what a person can or cannot do |
Venezuela | XIII Censo General de Población y Vivienda | 2001 | 1 | Uses a question such as 'Do you have disability?' |
Vietnam | Population and Housing Census | 2009 | 5 | Used the Washington Group Questions as recommended |
West Bank/Gaza | Expenditure and Consumption Survey (ECS) | 2009 | 3 | Uses a question on functional limitations, i.e. what a person can or cannot do |
Yemen | Demographic Health Survey | 2013 | 1 | Uses a question such as 'Do you have disability?' |
Zambia | Population and Housing Census | 2010 | 1 | Uses a question such as 'Do you have disability?' |
Zimbabwe | Living conditions among people with disability survey, key findings report | 2013 | 5 | Used the Washington Group Questions as recommended |
Zimbabwe | Disability and poverty in developing countries: a multidimensional study | 2013 | 5 | Used the Washington Group Questions as recommended |
Zimbabwe | Poverty Income Consumption Survey | 2019 | 3 | Uses a question on functional limitations, i.e. what a person can or cannot do |