In 2006, the United Nations adopted the Convention on the Rights of Persons with Disabilities, but it took until November 2016 for the first official Disability Toolkit to be launched.
Efforts to understand the extent of disability and interventions required are marred by difficulties in data collection. In 2006, at the time the UN’s disability convention was adopted, the WHO thought that only 500 million people in the world were affected by disabling health problems — half as many as were identified six years later in 2011 WHO World Report on Disability.
Definitions of disability vary. Blindness and visual impairment, for example, affects around 253 million people, according to the World Blind Union. But this ranges from people with partial sight who can perform a variety of jobs to total blindness. With good support, blind people can live independent and fulfilling lives, but without adequate training in independent living, they may experience lifelong dependency.
While well-known and visible disabilities, such as missing limbs or blindness, receive much attention, chronic diseases such as heart disease, diabetes and mental illness account for more than 66 percent of all years lived with disability in developing countries, according to the WHO. Years lived with a disability is a measure that takes into account that some disabilities start at different life stages and some, such as mental illness, may not be permanent.
Around one in four people will have a mental health condition at some point in their lives, and around 450 million people suffer from one at present, but again, these are less likely to be diagnosed in developing countries, where awareness around common illnesses such as depression remains low.
To try to create more clarity, the WHO has begun to collect more detailed data. According to its latest estimates, around 3 percent of the world’s population — between 110 and 190 million adults — experience “severe disability”, meaning they cannot manage daily life without assistance.