Disability Statistics
Note:
The CPACC will test on your ability to demonstrate an understanding of the data trends and implications of disability demographics and statistics.
Learning Goals of This Section
To prepare for the disability statistics portion of the exam, be sure that you are able to address and answer the following:
Understand why disability statistics are collected and how they are used
Explain why disability statistics are difficult to compare across countries
Identify the estimated percentage of people with disabilities in different countries, regions, and in the world
Identify the percentages of people with different types of disabilities in different age groups
Identify how many people with disabilities are employed, living in poverty, or have limited disposable income
Explain the health inequities faced by people with disabilities, including earlier mortality, higher risk of secondary conditions, and barriers to transportation and healthcare
In This Section:
Incidence and Prevalence
Why Disability Statistics Are So Variable
Aging and Disabilities
Education and Employment
Poverty and Disability
Incidence and Prevalence
Understanding disability statistics is a core part of accessibility work. Numbers help make the case for accessibility, inform policy decisions, and give a sense of the scale of disability worldwide. However, disability statistics should always be interpreted with some caution.
The IAAP CPACC Body of Knowledge (BoK) identifies several reasons why disability statistics are inherently difficult to pin down. Definitions of disability vary across countries and studies. Some disabilities are underreported due to stigma. Many people with disabilities live in low-income settings where data collection is limited. Details about specific disabilities are usually not included in census surveys. And many people with disabilities have more than one disability, making categorization difficult. For exam purposes, use the figures in this section as your reference, as they reflect the sources cited in the BoK.
A smiling young woman in a wheelchair poses with her mom as they take a selfie together
Key Global Statistics
An estimated 1.3 billion people experience significant disability, representing 16% of the world’s population, or roughly 1 in 6 people. This makes people with disabilities the world’s largest minority group.
The World Health Organization also highlights the following:
People with disabilities die up to 20 years earlier than those without disabilities.
People with disabilities have twice the risk of developing conditions such as depression, asthma, diabetes, stroke, obesity, or poor oral health.
People with disabilities find inaccessible or unaffordable transportation 15 times more difficult than those without disabilities.
Health inequities faced by people with disabilities arise from stigma, discrimination, poverty, exclusion from education and employment, and barriers within the health system itself.
Statistics by Disability Type
Disability Type Key Statistics Source
Vision Impairment and Blindness At least 2.2 billion people globally have vision impairment or blindness. Of these, at least 1 billion have a vision impairment that could have been prevented or has yet to be addressed. WHO
Low Vision About 246 million people, or 3.5% of the world’s population, have low vision. About 90% of people with vision impairments live in low-income settings. WHO
Color Blindness (Red-Green) Affects 1 in 12 males (8.3%) and 1 in 200 females (0.5%). This is the most common form of color vision deficiency. BoK
Color Blindness (Blue-Yellow) Affects males and females equally. Occurs in fewer than 1 in 10,000 people worldwide. BoK
Hearing Loss An estimated 430 million people have disabling hearing loss. WHO
Central Auditory Processing Disorder Estimated to affect approximately 5% of the global population. BoK
Deaf-Blindness Between 0.2% and 2% of the world’s population is Deaf-Blind. Incidence is considered low. World Federation of the Deaf-Blind
Speech Sound Disorders Prevalence is higher among children (5 to 25% depending on age group) than adults (1 to 2%). Statistics vary due to inconsistencies in classification. ASHA
Selective Mutism Estimated to affect 0.47% to 0.76% of the population. BoK
Mobility Disabilities 11% of adults in the United States have mobility disabilities. Similar figures have been reported for countries in Europe and Canada. No specific global statistics are available. US CDC
Intellectual Disabilities An estimated 200 million people worldwide have an intellectual disability. Special Olympics
Dyslexia Estimated to affect 5 to 10% of the population, possibly as high as 17%. Among people with reading difficulties, 70 to 80% are likely to have some form of dyslexia. It affects similar numbers of boys and girls. BoK
Dyscalculia Estimated to affect 3 to 6% of people. BoK
ADHD Prevalence among children is estimated at 2 to 7% globally, and around 4% in adults. Approximately 2 to 3 out of 10 people with ADHD have challenges with attention and concentration but not impulsiveness or hyperactivity. BoK / UK NHS
Autism Approximately 1 in 100 people are affected by autism. Autism Europe
Nonverbal Learning Disability (NLD) Around 1 in 100, or 1%, of children in the United States may have NLD. It tends to affect boys and girls about equally. BoK
Epilepsy 50 million people have epilepsy globally, making it one of the most common neurological diseases. Approximately 3% of people with epilepsy have photosensitive epilepsy. WHO
Anxiety Disorders Prevalence varies from 2.5 to 7% by country. In 2017, an estimated 284 million people experienced an anxiety disorder, making it the most prevalent mental health disorder globally. WHO
Bipolar Disorder According to the WHO, 19 million people experienced bipolar disorder in 2019 worldwide. WHO
Schizophrenia Affects approximately 24 million people, or 1 in 300 people worldwide. WHO
Multiple/Complex Disabilities 10 to 15% of people with disabilities have complex needs. UK and Australian sources
A Note on These Figures
These statistics reflect the sources cited in the IAAP CPACC Body of Knowledge. Some figures may have been updated since the BoK was written, and you may encounter different numbers in other sources. If a question on the exam asks about a specific statistic, the BoK figures and BoK sources are your best reference point.
Why Disability Statistics Are So Variable
Disability statistics vary widely across studies and countries, and understanding why helps you interpret the numbers more critically.
A young man with cerebral palsy, sitting in a wheelchair, laughing and talking with his friend
How Disability Is Defined
There is no universal definition of disability, and surveys do not all use the same one. Narrow definitions produce smaller percentages; broader definitions produce larger ones. The wording of individual questions matters too. A vague question like “Do you have a disability?” will produce less reliable results than a precise one like “Do you experience difficulty seeing text well enough to read it, even when wearing glasses?”
Data Collection Methods
Some surveys ask individuals to self-report. Others rely on trained observers. These approaches produce different results. Context matters as well. When reporting a disability may lead to government benefits, people are more likely to disclose one. When it may lead to stigma or negative consequences, they are less likely to.
Political and Social Bias
Governments and organizations sometimes underreport disability figures to avoid unfavorable scrutiny. When stigma or political pressure shapes data collection, the results become unreliable and difficult to use meaningfully.
Comparing Across Countries
For all of these reasons, comparing disability statistics across countries, or even across different surveys within the same country, is inherently difficult. That does not make the data useless. Each study offers something worth learning from. The key is to interpret the numbers in context rather than treating them as absolute.
Aging and Disabilities
Older people are significantly more likely to have disabilities than younger populations. Many disabilities are acquired gradually as a natural part of aging, including changes to vision, hearing, mobility, and cognition. In fact, research from the United Kingdom found that only 17% of disabled people were born with their disabilities. The majority acquire them later in life.
Countries with large aging populations tend to have a higher proportion of people with disabilities overall, though factors like poverty and conflict can also drive disability rates in younger populations.
This trend reinforces why accessibility matters. As populations age globally, the need for accessible environments, products, and services will continue to grow.
Education and Employment
People with disabilities are less likely to complete traditional education and less likely to be employed, and these two trends are connected. Barriers within the education system, ranging from inadequate accommodations to outright inaccessibility, can limit the qualifications and opportunities available to students with disabilities. Lower educational attainment in turn affects employment prospects, contributing to a cycle of poverty and lost opportunity that can be difficult to break.
On the employment side, the picture is more nuanced than it might appear. In a minority of cases, a disability or related health condition does genuinely limit a person’s ability to work. In most cases, however, people with disabilities are willing and able to perform well in the workplace when given the chance. The more common barriers are external: workplace discrimination, inaccessible work environments, and assumptions made by employers about what a person with a disability can or cannot do.
Addressing these barriers through accessible design, inclusive hiring practices, and reasonable accommodations is not just a legal obligation in many countries. It is also good for organizations and for society as a whole.
Poverty and Disability
Disability and poverty are closely linked, and the relationship runs in both directions. Living with a disability can be expensive. Assistive technologies, medical equipment, home modifications, and personal care support all carry real costs that can strain individuals and families. Many people who need these supports cannot afford them, which compounds the impact of the disability itself.
At the same time, poverty can increase the likelihood of disability. In lower-income countries, deficiencies in healthcare, sanitation, and safety lead to higher rates of disability. People with disabilities in these settings are often among the most economically vulnerable, and the effects can persist across generations.
In wealthier countries, people with disabilities are still disproportionately likely to live in or near poverty compared to the general population, due to employment barriers, higher living costs, and gaps in support systems.