Summary:

The report begins by addressing the challenge of defining disability. It is recognised that there is variation in the nature and severity of disability, and that no single description is adequate to define it (Mont 2007; DFID 2015). Despite this challenge, the definition the UN Convention on the Rights of Persons with Disabilities (UNCRPD) (2006) provides is useful and appropriate, as it defines persons with a disability as including those who have long-term physical, mental, intellectual or sensory impairments which in interaction with various barriers may hinder their full and effective participation in society on an equal basis with others.

The contested definition of disability is one factor that complicates attempts to obtain an exact disability prevalence figure. Other factors include the quality and methods of data collection, rigour of sources and varying disclosure rates (Mont 2007; Al Ju’beh 2015). Poor service provision and stigma may result in lower disclosure. National statistics can be misleading, incomparable and inaccurate. These limitations may result in a higher prevalence of disability in developed countries being reported compared to developing countries (Al Ju’beh 2015).

Developing countries have predominantly collected disability data through censuses or use measures focused exclusively on a narrow choice of impairments. These countries tend to report low disability rates. Countries that collect their data through surveys and measure activity limitations and participation restrictions in addition to impairments tend to report higher
prevalence. Data gathered from institutionalised populations tends to result in higher prevalence rates (WHO and World Bank 2011). Despite these potential influences, the evidence suggests that low and middle income countries do in reality have higher disability prevalence, in comparison to high income countries (Mitra and Sambamoorthi 2014).