*** INTRODUCTION ***
According to the National Center for Health Statistics, over 34 million
Americans, more than 14 percent of the civilian non-institutionalized
population, are limited in their activity due to long-term disability.
Approximately 2 million more persons live in a variety of long-term care
institutional settings, including 1.5 million in nursing and related-care
homes and nearly a quarter million, each, in mental health and mental
retardation facilities. These figures, however, only begin to convey
information about the number and condition of persons with disabilities,
given the myriad, often conflicting, array of information available on this
segment of the population.
To put these figures in perspective, the Digest presents data from a variety
of sources as an introductory reference on the definition, measurement,
prevalence, and characteristics of persons with disabilities in the United
States. The purpose of this report is to foster a conceptual understanding
of this complex subject and present information in tables and accompanying
narrative which describe various aspects of disability. While the main
purpose of the Digest is the direct presentation of statistical information,
narrative accompaniment provides assistance in data interpretation. To
ensure objectivity, this publication contains only data and explanations
issued by federal statistical agencies, unless otherwise noted.
The Digest consists of an introductory section which first presents
definitions and measures of disability, then summarizes prevalence figures
according to the various national surveys and federal programs serving
persons with disabilities. This is followed by a series of tables, with
accompanying highlights and explanatory notes on the data, providing detailed
information in this regard. A references section at the end of this
introduction lists sources for securing additional information on the subject
of disability.
** Definition and Measurement of Disability
The World Health Organization defines disability as "any restriction or lack
(resulting from an impairment) of ability to perform an activity in the
manner, or in the range, considered normal." This means that, apart from its
underlying origins and ultimate effects, disability is a limitation in life
activities, such as working and living independently, caused by impairments
or other chronic conditions, such as blindness or arthritis. Disability
involves many areas of functioning, such as physical (e.g., walking),
emotional (e.g., personal relationships), and mental (e.g., problem solving).
Although acute conditions, those of a short duration, do cause disabilities,
the existing literature on this subject focuses almost exclusively on
limitations related to long term, or chronic conditions. Accordingly, the
terminology, definitions, and data in this publication do so as well, unless
otherwise stated. The rationale is that acute conditions, while having an
immediate effect, do not usually require prolonged behavioral or social
adaptations.
Although there is considerable agreement on the meaning of chronic
conditions, such as the International Classification of Diseases, ninth
revision (ICD-9), there is wide variation on how best to describe and measure
the disabling effects these conditions have on individuals. In a digest of
data, a definition of disability is most useful if it can be quantified and
related to the accompanying prevalence statistics. Realistically, a single
meaning and measure of disability cannot fit the range of data from the
multiple surveys and other sources this report includes.
While the terminology and measures, below, show that definitional
complexities and inconsistencies do exist, they also illustrate the
multi-dimensional nature of disability and the corresponding need for
separate statistics on the various types of limitation. For example, a
person with no limitation in the ability to work may nonetheless be limited
in performing activities of daily living at home, such as dressing and
bathing. The subject of disability has many facets, and for this reason the
readers should select particular tables for reference based on their specific
information requirements. A major objective of this publication, therefore,
is to present a broad perspective and assist in selecting from among the
various sources of information.
Definitional differences aside, the focus of many disability studies is on
describing the various types of limitations which are caused by chronic
health conditions, as opposed to the conditions themselves. Rather than
treating disability as a disorder in need of correction, this approach
considers the functional capacity and needs of the individuals involved.
This non-medical perspective on disability has gained wide acceptance in the
professional community, notwithstanding the clear benefits of treatment,
health promotion, disease prevention, and the use of such technology as
medical device implants and assistive devices.
An emphasis on limitation in specific activities such as eating or walking,
in conjunction with the chronic health conditions involved, also helps
decision makers and others use data to identify service requirements and
other forms of intervention which could help address the needs of persons
with disabilities. Indeed, the entire Independent Living movement, which has
significantly influenced public policy in this regard, focuses on ways to
enable persons with disabilities to fully participate all aspects of society,
through rehabilitation training, appropriate services, and the elimination of
physical and attitudinal barriers.
As summarized in the Appendix, the Americans with Disabilities Act is another
example of this focus on functioning and the participation of persons with
limitations in the mainstream of society. In this regard, the law requires
reasonable accommodation by employers; access to public and private services
such as transportation, telecommunications, restaurants, hotels, and shopping
establishments; and discourages discrimination against persons with
disabilities.
Yet the individual chronic conditions which cause disability are of genuine
interest to the reader, given that services and products, such as those for
the visually impaired, are often designed specifically for them. This is
especially true for physical versus mental health conditions. For this
reason, the prevalence of specific chronic health conditions is presented in
many of the tables, along with the nature and severity of the limitations
they cause. However, chronic conditions, alone, are not good measures of
disability because many produce little if any limitation.
** Activity Limitation -----------------------------------------
| |
The National Center for | Percent of Persons by Degree of |
Health Statistics (NCHS), | Activity Limitation Due to |
from which this Digest draws | Chronic Conditions, 1989 |
most of its information, uses | |
the concept of activity | |
limitation to measure | XXXX+ Major: Unable 4.1% |
disability, which it defines | XXXXX+ Major: Amount/Kind 5.4% |
as "long-term reduction in | XXXX+ Non-Major Activity 4.5% |
activity resulting from | |
chronic disease or | XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX |
impairment." In its annual | XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX |
National Health Interview | XXXXXXXXXXXXXXXXXXXXXXXXX+ |
Survey (NHIS), NCHS describes | No Limitation 85.9% |
a limitation in terms of the | Type of Activity Limitation |
major activity it considers | |
usual for one's age group: 1) | Figure 1 |
ordinary play for children | Source: National Center for Health |
under 5 years of age, 2) | Statistics, 1989 National Health |
attending school for those | Interview Survey. Vital and Health |
5-17 years of age, 3) working | Statistics, Series 10, No. 176, |
or keeping house for persons | Table 68. |
18-69 years of age, and 4) | |
capacity for independent |----------------------------------------
living (e.g., the ability to bathe, shop, dress, eat, and otherwise care for
oneself without the assistance of another person) for persons after age 69.
NCHS determines the severity of the disability by asking respondents whether
they are 1) unable to perform their major activity, or, if they can, whether
they are 2) limited in the amount or kind of major activity, the former
defined as severe.
If persons are not limited in their major activity, NCHS asks if they are
limited in other ways, which it also calls non-major or outside activity.
Normally, non-major activities are less challenging than major ones, and
these other activities include social, civic or recreational endeavors.
However, for those 18-69 years of age who keep house, and persons 70 years of
age and over, measures of outside activity also include the ability to work,
reversing the relative challenge of major and outside activity, especially
for those 70 years of age and over. This issue is important in understanding
the tables of NCHS activity limitation figures for various age groups.
Using this definitional schema, NCHS estimates that 14.1 percent of the U.S.
population have an activity limitation, as Figure 1, above, shows. This
includes 4.1 percent who are unable to carry on their major activity at all,
5.4 percent who are limited in the amount or kind of major activity, and 4.5
percent who are limited but not in their major activity (the total figure is
affected by rounding).
** Functional Limitation
|--------------------------------------|
| |
The Census Bureau provides | Percent of Persons 15 Years of |
another measure of disability | Age and Over by Degree of |
through the 1984 Survey of | Functional Limitation, 1984 |
Income and Program | |
Participation (SIPP). This | |
study of | XXXXXXX+ Severe Limitation 7.5% |
non-institutionalized persons | XXXXXXXXXXXXX+ |
15 years of age and older | Non-Sever 13.1% |
collected information about a | |
person's ability to perform | XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX |
nine sensory and physical | XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX |
activities, including: | XXXXXXXXXXXXXXXXXXX+ |
| No Limitation 79.4% |
1. seeing words and letters in | |
ordinary newspaper print even | Degree of Functional Limitation |
when wearing glasses or | |
contact lenses; | |
| Figure 2 |
2. hearing what is said in a | Source: U.S. Bureau of the Census |
normal conversation; | 1984 Survey of Income and Program |
| Participation. Current Population |
3. having speech understood; | Reports, Series P-70, No. 8, |
| Table C. |
4. lifting and carrying a | |
full bag of groceries (10 |______________________________________|
lbs.);
5. walking three city blocks (1/4 mile);
6. walking up a flight of stairs without resting;
7. getting around outside the house by yourself;
8. getting around inside the house by yourself; and
9. getting into and out of bed by yourself.
Except for having speech understood, respondents also reported on the
severity of their difficulty by indicating 1) if they had difficulty and 2)
if they were unable to do the activity at all or without the assistance of
another person, the latter defined as severe.
From this household survey, the Census Bureau estimates that 20.6 percent of
the population, or 37.3 million persons 15 years of age and older, had a
functional limitation, i.e., difficulty performing one or more of the
specific activities, including 7.5 percent with a severe one (see Figure 2,
above). This leaves a residual category of 13.1 percent with a non-severe
functional limitation. Unlike the NHIS where the definition of limitation
varied based on one's age and major activity, the 1984 SIPP measured
functional limitation using the same definitional criteria for all
respondents.
** Need for Assistance in Activities of Daily Living (ADL) and Instrumental
Activities of Daily Living (IADL)
|----------------------------------------------|
One important distinction in | Percent of Persons 15 Years of Age and |
the measurement of disability | Over Who Need Assistance with |
is the extent to which an | Everyday Activities, 1986 |
individual requires the | |
assistance of another person | |
to perform basic life | XXXX+ Need Assistance 4.4% |
activities (personal | |
assistance), such as | |
dressing, eating, personal | XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX |
hygiene and getting around | XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX |
outside the home. To a much | XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX |
greater extent than the | XXXXX+ |
activity limitation and | Need No Assistance 95.6% |
functional limitation | |
definitions, the need for | Note: Need for Assistance with Everyday |
personal assistance is an | Activities is similar to the ADL/IADL scale |
effective measure and | |
valuable predictor of a | Figure 3 |
person's ability to live | Source: U.S. Bureau of the Census |
independently in the | 1984 Survey of Income and Program |
community. | Participation. Current Population |
| Reports, Series P-70, No. 19, |
| Table A. |
| |
|----------------------------------------------|
As one example of this disability measure, the Census Bureau's 1986 SIPP
asked persons 15 years of age and over if they required the help of another
person to carry on the following activities due to a health condition that
had lasted or was expected to last three months or longer:
1. taking care of personal needs such as dressing, eating or personal
hygiene;
2. getting around outside the household;
3. doing light housework such as washing dishes, straightening up or
light cleaning;
4. preparing meals; and
5. keeping track of bills and/or money.
In this case, by measuring the extent to which respondents needed the help of
other persons in performing one or more of the above activities, the Census
Bureau estimates that 4.4 percent of the population, or 8.2 million persons
15 and older required personal assistance (see Figure 3).
Another way of measuring disability in this context is the extent to which
persons need assistance with multiple activities. Of the 8.2 million persons
requiring the help of others with one or more activities, over one-quarter
needed personal assistance with one activity, nearly three-quarters needed
help with two or more activities, and over half needed help with three or
more activities (see Figure 4, below).
|--------------------------------------------|
The disability measures in | Distribution of Persons 15 Years of |
the 1986 SIPP are similar | Age and Over Who Need Assistance, |
to two other frequently | by Number of Activities, 1986 |
used indicators of need for | |
assistance - | |
| XXXXXXXXXXXXXXXXXXXXXXXXX+ |
limitation in Activities | One Activity 25.4% |
of Daily Living (ADL) and | XXXXXXXXXXXXXXXXXXXXXXXX+ |
Instrumental Activities of | Two Activities 24.3% |
Daily Living (IADL). ADL | XXXXXXXXXXXXXXXXXXXXXXXXX |
include the basic tasks of | XXXXXXXXXXXXXXXXXXXXXXXXX+ |
1) bathing, 2) dressing, 3) | Three + Activities 50.3% |
using the toilet, 4) | |
transferring (in and out of | Percent Needing Assistance with |
bed or chair), 5) | Multiple Everyday Activities |
continence, and 6) eating; | |
IADL go beyond ADL in level | |
of complexity and include | Note: Need for assistance measures |
1) handling personal | are similar to the ADL/IADL scale |
finances, 2) meal | |
preparation, 3) shopping, | Figure 4 |
4) traveling, 5) doing | Source: U.S. Bureau of the Census |
housework, 6) using the | 1984 Survey of Income and Program |
telephone and 7) taking | Participation. Current Population |
medications. | Reports, Series P-70, No. 19, |
| Figure 1. |
| |
|--------------------------------------------|
The mobility activities of
walking and going outside
are also considered by
disability statisticians to be activities of daily living (ADL). However,
because persons are better able to overcome a mobility limitation than other
ADL difficulties, through the use of assistive devices such as walkers, canes
and wheelchairs, they do not fit the hierarchical pattern of the other six
activities in terms of severity and the need for assistance from others. For
this reason, disability reports often present limitation in mobility
activities separately (see Table 5).
The ADL scale represents a more basic level of functioning than the IADL,
and, therefore, constitutes the most severe of the two measures. For this
reason, many persons with an ADL limitation also have an IADL limitation as
well.
Unlike activity limitation and functional limitation, as defined above, which
are very broad measures unique to the two surveys which use them, many
studies assess the need for ADL and IADL assistance, albeit using different
activity lists. These studies include other components of the annual NHIS,
the NHIS 1984 Supplement on Aging (SOA) (Figure 7) and 1979-1980 NHIS Home
Care Supplement, 1982 and 1984 National Long-Term Care Survey, National
Medical Expenditure Survey (NMES) 1987 household (Table 5) and institutional
components (Table 33), and the 1985 National Nursing Home Survey (NNHS)
(Table 26), among others.
Many professionals in the disability statistics arena prefer ADL/IADL
measures over others because they focus attention on the needs common to
persons with severe disabilities, apply to both household and institutional
populations, reveal the particular types of assistance persons require
regardless of age or setting, and are useful in determining eligibility for a
range of long-term care services and benefits.
One caveat associated with ADL/IADL surveys is that the number of persons
reporting limitations in one or more ADL or IADL increases with the number of
activities a particular study uses. Relatively long activity lists produce
relatively high prevalence rates. Apart from the sheer number, studies vary
according to which particular activities they include or the extent to which
several are grouped into a single category. Also, some studies measure
multiple levels of difficulty in performing a particular activity according
to the type of assistance required, such as special equipment or the help of
another person. As an example of these variations, some studies exclude
continence and mobility measures from the ADL scale. Others divide mobility
into the two activities of walking and getting outside. The 1986 SIPP
combines all ADL measures into one category called "personal care" (Table 4),
while the National Medical Expenditure Survey measured these items separately
and according to several levels of difficulty (Table 5). The tables in the
Digest reflect these variations, requiring care in interpretation, as
explained in the narrative accompanying each one.
These inconsistencies make comparisons among multiple ADL/IADL studies
difficult unless one focuses on general demographic patterns associated with
disability, views only particular activities on the lists, or converts data
from the multiple studies to an activity list common to all (see Table 6 for
such a conversion for the elderly population). In an effort to reconcile
these differences, at least for the elderly population, many professionals
focus on a core set of five activities from the ADL scale (bathing, dressing,
transferring in and out of bed and chair, using the toilet, and eating) as an
effective basis for assessing need and determining eligibility for long-term
care services.
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