About 15 percent of the world's people suffer from a disability, and the proportion is set to grow as the population ages, the World Health Organisation and World Bank said in a report published Thursday.
In the 1970s, the WHO published data indicating that about 10 percent of the world's population suffer from a disability.
But now based on its 2010 estimates, the WHO and World Bank's World Report on Disability said that "a billion people live with some form of disability, making up an estimated 15 percent of the world population."
Among them, about one in five, or nearly 200 million, suffer from a severe disability.
"In the years ahead, disability will be an even greater concern because its prevalence is on the rise," warned WHO director-general Margaret Chan and World Bank chief Robert Zoellick in the preface of the report.
"This is due to ageing populations and the higher risk of disability in older people as well as the global increase in chronic health conditions such as diabetes, cardiovascular disease, cancer and mental health disorders."
Even though some countries have made progress in improving the daily lives of people with disabilities, much remains to be done, said the report.
The disabled have three times higher risks of being refused necessary medical care, the report said.
In addition, they can also be excluded from broader society, be it from employment or schooling.
"We need schools, employment to be accessible to people with disabilities... rather than to be segregated," said Etienne Krug, director of the WHO's department on prevention of violence, trauma and disability.
"We need to adopt in every country a national plan" for the disabled, he added, pointing out that disability affects the most vulnerable populations, including the poor, elderly, women and children.
According to the WHO, some 95 million children have a disability. Of these, 13 million suffer from severe disabilities.
While schooling rates for children with disabilities differ according to the type of disability, those with intellectual or sensory deficiencies tend to fare worse than others who suffer from physical deficiencies.
The most excluded group from the employment market are those with mental health problems or intellectual deficiencies, added the report.