Child disability:
definitions, models, measures, estimates
and implications for data collection
Claudia Cappa, Andrew MacKenzie
Statistics and Monitoring Section
UNICEF/NY
Challenges in Identifying and
Measuring Disability among Children in Low and
Middle-Income Countries
Major challenges
• UN General Assembly Special Session on Children (2001)
highlighted the difficulty in gathering accurate data on the
incidence of disability among children and referred to the
fact that:
 countries have used different definitions of both
impairment and disability
 the quality of statistical data varies widely
 too little research has been done on the lives of disabled
children
Plus: stigma and complexity linked to data collection
3
Review of prevalence studies
• Prevalence rates vary from 2%-50% depending on definition or measure
• Different classifications, definitions
comparisons between surveys
and
questionnaires
limit
• No survey designed to cover the whole population of disabled children
• Data sources limited by age, geography, size of subgroups and place of
residence
• Very few data sources collect data on social and demographic
circumstances
• Few take account of how age and development of children may shape
functioning and ability
Adapted from Meltzer H. , Washington Group Meeting, Luxembourg, 2010
The case of Uganda
Percentage of population reporting some form of disability
25
Do you have
difficulty seeing,
hearing, walking,
etc?
20
20
15
10
Is anyone
in the
household
disabled?
5
7
4
1
0
Census 1991
Population and
housing census 2002
Uganda National
Household Survey
2006
Demographic and
Health Survey 2006
Additional issues
– Questions addressed to adults are inappropriate or different in kind
for children (e.g. falling over, reaching and stretching, behavioural
problems)
– Questions addressed to children are sometimes inappropriate for
adults (e.g. crawling, running, communicating)
– When should developmental delay be regarded as disability
– Parental knowledge of norms, standards and children performances
(ex. In schools)
– Variations by culture
– Does one look at what child can do, does do, wants to do or is allowed
to do? Importance of the family and social context
Adapted from Meltzer H. , Washington6 Group Meeting, Luxembourg, 2010
CRPD
• Art 1. Persons with disabilities include those who have longterm 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.
• Art 31. States Parties undertake to collect appropriate
information, including statistical and research data, to enable
them to formulate and implement policies to give effect to
the present Convention.
Disability Measurement Overview
• Theoretical Approaches to Disability
• What is disability?
• WHO Disability Classifications
• History & development
• Applications for survey design
• Measuring Disability
• ICF in action
The Key Question….
•Why can’t I reach the top?
•My disability?
•My environment?
Theoretical Approaches to Disability
• Many models and definitions of disability
• Medical model
• Social model
• Bio-psychosocial model
Medical Model of Disability
• Definition of disability:
• Any restriction or lack of ability to perform an
activity considered normal for a human being
• Oriented towards:
• Clinical diagnosis
• Treatment, cures, and prevention
• Responsibility for disability:
•
Person needs to be cured, rehabilitated or
adapted to society to function “normally”
Social Model of Disability
• Definition of disability:
• restrictions caused by society when it does not
give equivalent attention and accommodation
to the needs of individuals with impairments
• Oriented towards:
• Accessible environments
• Full participation in society is a civil right
• Responsibility for disability:
• Society
Bio-Psychosocial Model of Disability
• Definition:
• Unsuccessful interaction between a person with
an impairment and an unsupportive
environment
• Oriented towards:
• Interactions of impairments & environments
• Accessible environments & inclusive design
• Responsibility for disability:
• Everyone needs to work together
Bio-Psychosocial Model of Disability
WHO Disability Classifications
Development History - ICF
• Classification system for outcomes of
disease (NOT a measurement tool)
• Sister publication for ICD
• Development began in 1972
• International Classification of Impairments,
Disabilities and Handicaps (ICIDH)
• First edition 1980
• Criticized for “Medicalization of disability”
• Second edition 1993
Development History - ICF
• Revision process for ICIDH began in 1993
• New conceptual framework
• Bio-psychosocial model
• Evaluations
• Conferences
• Field trials
• Resulted in development of the ICF
Development History - ICF
• Classification system for functioning,
disability and health
•
•
•
•
Body functions
Body structures
Activities and participation
Environment
• Still not a measurement tool
Development History - ICF
• Endorsed by WHO general assembly-2001
• Currently endorsed by 192+ member states
• Member states use the ICF for:
•
•
•
•
Classification
Research
Surveillance
Reporting
ICF – International Standard
• To provide a scientific basis for outcomes
of health conditions
• To establish a common language to
improve communications
• To permit comparison of data across:
•
•
•
•
countries
health care disciplines
services
time
• To provide a systematic coding scheme for
health information systems
How Does ICF Work?
• Systematic coding system with
descriptions of varying detail
• Primary domains:
• Body functions
• Body structures
• Activities and participation
• Environment
• Sub-domains
Activities and Participation
• Activities: the execution of a task or action
• Participation: involvement in a life situation
• Partial overlap between domains
• Detailed categories as activities and broad
categories as participation
Activities and Participation
•
•
•
•
•
•
•
•
•
Learning & applying knowledge
General tasks and demands
Communication
Movement
Self care
Community, social & civic life
Domestic life areas
Interpersonal interactions
Major life areas
Environmental Factors
•
•
•
•
•
Products and technology
Natural environment and human changes
Support and relationships
Attitudes
Services, systems and policies
• Facilitators
• Barriers
How ICF Works: An Example
• Activities and participation domain (d)
• Applying knowledge (d160-d179)
• Solving problems (d175)
• Solving simple problems (d1750)
•ICF Definition: Finding solutions to a simple
problem involving a single issue or question, by
identifying and analyzing the issue, developing
solutions, evaluating the potential effects of the
solutions and executing a chosen solution.
Measuring Disability
Measuring Disability
• Many different ways to measure disability
• Purpose of the data
• Data collection
•
•
•
Statistics
Research
Monitoring
• Social policy
•
•
Eligibility for programs
Monitoring progress toward full inclusion
Measuring Disability
• Thousands of ICF codes
• Limited patience of respondents
• Strategic selection of domains
• Ask capacity or performance questions
• Never opinion questions
• Select questions to fit purpose
Example 1. Agility
• ICF Codes:
•
Activities and participation domain
•
d540 Dressing
•
•
d5400 Putting on clothes
d5401 Taking off clothes
• Potential Question:
•
Do you have any difficulty dressing and
undressing yourself?
Example 2. Agility
• ICF Codes:
•
Activities and participation domain
•
•
d520 Caring for body parts
d5204 Caring for toenails
• Potential Question:
•
Is it physically difficult for you to cut your own
toenails?
ICF Survey Topics for Children
Portrait of the child:
Portrait of their life:
•Body functions
•Body structures
•Diagnoses
•Medication
•General health
•Contact with health care
•Activities & participation:
–Leisure activities
–Social integration
–Education
•Environment:
–Barriers and supports
–Accommodations
–Assistive technology
–Discrimination
The Future of ICF
• ICF-2 initial discussions have begun
• Electronic health records
• Development of survey questions
• Impacts of barriers and supports
• Measuring accessibility of environment
• Measuring degree of functional limitations
Overview of Available Estimates
Data sources
• Administrative data
Limitation: services for children with disabilities are not universally available. Administrative data, if available at all, will not
provide a complete account
 Censuses
Limitation: evidence that census data under-enumerate children with disabilities -disadvantaged children with disabilities, & especially those with less ‘visible’
especially girls & socioeconomically
 Key informant approaches
Limitation: miss disabilities that are not publicly evident such as intellectual and hearing disabilities, and to include children from
outside the population of interest
 General surveys (all members of the household)
Limitation: underreporting due to inappropriate screening tools for age
 Separate surveys of children or surveys with specific module for
children
Who collects prevalence
data on disability at the international level
• ILO (as part of Labour Surveys, adults only)
• World Bank (adults only)
• WHO in 2002-2004 (adults only) and possibly a new
one in next future (adults only)
• UNICEF (only agency to collect comparable data on
children through MICS)
Global estimates
• 150 million children in the world with disabilities (WHO,
UNICEF and other)
• 200 million children in the world with disabilities (WHO,
UNICEF and other)
• Between 120 and 150 million children in the world with
disabilities (UNESCO)
Global estimates
WHO estimate of 10% for global disability prevalence
dates back to the 1970s
1981 report produced by the WHO Expert Committee on Disability Prevention
and Rehabilitation = first published record citing this 10% prevalence rate,
stating:
A document submitted to the World Health Assembly in 1976 included a summary of
the results of the most important studies of disabilities undertaken in developed
countries and of estimates of the prevalence of impairing conditions in a number of
developing countries. From this and other information no more accurate an estimate
can be made than that the disabled comprise about 10% of the world’s population
Global estimates
• 2011 World Report on Disability
– 15.3% “moderate or severe disability”
– Persons 15 years and over: 15.6% to 19.4%
– Children 0-14 years: 5.1%
• Two sources of statistical information
World Health Survey 2002-2004 = Adults 18 and above only
Global Burden of Disease = underestimate disability in children
• The WHO/World Bank 2011 report notes that these prevalence
estimates should not be taken as definitive but as reflecting current
knowledge and available data (p. 25)
Other estimates: education
• 99 per cent of girls with disabilities are illiterate
(Richler, Diane, Quality Education for persons with
disabilities, background paper presented for the Education for All Global Monitoring Report 2005: The Quality Imperative 2005)
• One third of children out of school have a disability (World Bank)
• 40 million out-of-school children have some form of disability (UNESCO)
• More than 90% of children with disabilities in developing countries do not
attend school (UNESCO)
UIS does not have an official estimate nor endorses statistics on the links
between disability and access to education
Other estimates: child protection
• 30% of the world's "street" children are living with
disabilities
• 600,000 children
disabilities
in
institutions
globally
have
There is currently no reliable figure of street children and
children living in institution and, given the challenges
highlighted above in identifying children with disability, it
is not possible to have a reliable number of the children
with disability who are institutionalized or living in the
streets
Child Disability in MICS
History
• MICS 2 (2000-2001), 22 countries collected data on child disability.
• MICS 3 (2005-2006), 26 countries collected data on child disability, using
the same standard set of questions (TQ)
- module administered in 19 written languages
• MICS 4 (2010-2012), 4 countries (completed) as of January 2012
• MICS is the largest population-based source of data using the same
screening tool for child disability
The MICS Module on Child Disability: Rationale
 TQ developed by a team of scientists (M. S. Durkin et al.). Its validity has been
tested in different epidemiological surveys involving screening and clinical
assessments of more than 22,000 children, in Bangladesh, Pakistan and
Jamaica
 Looks specifically at activity limitations and conditions (ICF framework)
 Ten questions addressed to parent or caregiver, yes/no format and some
reverse worded questions
 Focus on universal abilities, cross-culturally comparable
 Reliance on caregiver ratings of child’s development & behavior relative to
own cultural norms
 2-9 year age range
 Shown not to be gender biased (equally valid for girls & boys)
Questionnaire
•
If the child:
(1) Has delay in sitting, standing or walking
(2) Has difficulty seeing, either in the daytime or at night
(3) Has difficulty hearing
(4) Has difficulty in understanding instructions
(5) Has difficulty walking or moving arms or has weakness or stiffness of limbs
(6) Has fits, becomes rigid, loses consciousness
(7) Does not learn to do things like other children his/her age
(8) Does not speak at all
(9) Speaks differently from normal or cannot name at least one object
(10) Appears mentally backward, dull or slow
Some considerations on the TQ
• The ‘Ten Questions’ is a screening tool; for those screening positive a
professional diagnostic assessment is required
• Validity established only for relatively severe disabilities (intellectual, motor,
seizure). Sensitivity is low for mild disabilities, and for vision and hearing
disabilities generally
• Positive predictive value of 20-25%
• Not valid for establishing prevalence by type
• Limited to children 2-9
• Validity not established for behavioral disabilities such as autism and
attention deficit disorders
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Percent
Some results
Percent Screening Positive to any of TQ (95% CI)
100
90
80
70
60
50
40
30
20
10
0
Ten Questions & 2-Phase Design
1 0 Q u estion s S creen
n =1 0 ,0 0 0
S creen ed P ositive
10 - 20%
C lin ical E valu ation
D isab ility
"tru e p ositive"
N o D isab ility
"false p ositive"
S creen ed N eg ative
80 - 90%
C lin ical E valu ation
1 0 % ran d om sam p le
D isab ility
"false n eg ative"
N o D isab ility
"tru e p ositive"
N o F ollow-U p
7 0 -8 0 %
Current and planned activities
The way forward – Part 1
• Revision of the questionnaire for the first stage
–
–
–
–
expand the age group
include additional functional domains
introduce changes in wording
introduce changes in response categories
• New draft questionnaire developed in partnership with the
Washington Group on Disability Statistics
• Goal: new questionnaire to be applicable as screening tool
to identify children with a high likelihood of disability even
outside the MICS context
The way forward – Part 2
Development of a standardized methodology for second stage follow-up, based on
existing best practice approaches for the evaluation and diagnosis of disability in
children in developing countries
Objective: to validate data and collect additional information on the child, and
his/her environment (including additional questions on participation, access to
services, family life etc)
The package will include:
protocols
tools
instructions
training program/materials
analysis plan and reporting template
minimum qualifications for the field team
ethical codes
procedures for follow-up in cases where a form of disability is detected, etc.
Goal: Package to be applicable in providing guidance for the screening and
identification of children even outside the MICS context
Processes and partnerships
•
Team of experts mobilized, including :
– UNICEF Team in NY (1 survey coordinator, 2 survey specialists, 2 data processing
experts, 2 data analysis experts, Disability Unit)
– MICS coordinators in the regional and country offices
– University of Wisconsin
– Washington Group on Disability Statistics
– External partners (selected academics, practitioners, NGOs and international
organizations)
– DHS
•
Two upcoming consultations (6-8 June, end of July)
•
Cognitive testing and validation in fall 2012
•
Guidelines, tools and training materials to be tested and finalized by early
2013
Thank you
ccappa@unicef.org
ammackenzie@unicef.org