Purposes%20of%20Disability%20Statistics

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Purposes of Disability Statistics

• Mitchell Loeb
• National Center for Health Statistics, USA
• for the Washington Group on Disability Statistics

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Disability statistics

• Purposes of disability measurement vary
• Therefore, it is important to know
• Who needs this information?
• Why do they need this information?

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Who needs this information?

• Researchers
• Stakeholders
• Data users
• Public / citizens
• Policy makers
• Associations (NGOs)
• Trade unions
• Government agencies
• International organizations

• Health service organizations / providers
• Industry
• Device / equipment manufacturers
• Employers
• Consumer groups
• Insurance agencies
• Education planners
• Media

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Why do they need this information (for what
purpose)?

• Planning
• Evaluation
• Marketing
• Policy development and evaluation / Political
  action
• Advocacy
• Prevention
• Enhance participation
• Improve services
• Standard rules

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Primary purposes for disability statistics

• Needs assessment / service provision
• Focus is on the individual who will be served by
  the program or product
• Trend monitoring
• Focus is to identify changes in prevalence rates
  of a particular indicator in the population that
  reflects policy concerns
• Equalization of opportunities
• Focus is on the population that will benefit from
  improved access through civil rights legislation
  and development of programs and policies

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Needs assessment/service provision

• Eligibility for benefits
• Income support / social security
• Subsidies
• Device manufacture
• Formal rehabilitation services
• Education programs
• Medical rehabilitation
• Vocation rehabilitation
• Personal assistant services
• Advocacy services

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Needs assessment / service provision

• Seeks to identify those with specific needs,
  usually the most serious problems
• Requires detailed information about the person
  and their environment
• Influenced by the organization and structure of
  service organizations and support programs within
  a particular culture

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Locating population for service provision in the
ICF Model
Body Structure Function
ACTIVITY
Source World Health Organization, 2001
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Example 1 Needs assessment / service provision

• NGO wants to develop after school programs to
  assist children with developmental disabilities
• Focus is a select population samples can
  probably be drawn from administrative data
• In-depth information about childrens activity
  and participation limitations will provide
  information around which a program can be
  organized
• NGO specialization will help identify the domains
  of activity or participation that are relevant
• Data may be specific to the cultural and
  geographic area where information is collected
  (not necessarily nationally representative)

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Example 2 Needs assessment / service provision

• Government agency wants information on the
  population in need of income support
• Generally obtained from administrative data but
  limited to those who apply
• Can obtain from population based methods but
  questions need to replicate (be specific to)
  eligibility requirements

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Trend monitoring

• Ongoing estimation of population characteristics
  related to functioning
• Prevalence rates
• Trends

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Monitoring trends in functioning in the population

• Seeks to identify all those with limitations in
  activities as usually performed in a persons
  environment
• Dependent on individual and environmental
  characteristics with whatever adaptations that
  have been made

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Locating population for trend monitoring in the
ICF model
ACTIVITY
Participation
Source World Health Organization, 2001
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Example Monitoring trend in functioning

• Information is used to characterize the barriers
  to inclusion of the population
• Measuring the interaction of people and
  environments

Population reporting limitation in transportation
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Equalization of opportunities

• Seeks to identify those at risk of experiencing
  limitations in participation because of
  limitations in basic activities
• Requires measurement of the overall level of
  functioning of the person regardless of the
  health problem or condition that creates the
  limitations
• Measurement is done trying to hold the
  environment neutral

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Locating population at risk for inequality of
opportunities in the ICF model
?
ACTIVITY
Source World Health Organization, 2001
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Example Equalization of opportunities

• A new transportation system is initiated
• Need to determine if system used by persons with
  functional limitations as well as general public
• Survey used to identify use of/satisfaction with
  system
• Along with identification of gender and age of
  respondent, those at risk of participation
  limitations (i.e. those with limitations in basic
  activities) are also identified
• System use and satisfaction can be compared
  between those who are and are not at risk of
  participation limitations
• Equalization results when the patterns are the
  same / similar

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Example Equalization of opportunities

• Seeks to identify all those at greater risk than
  the general population for limitations in
  activity or participation
• Disability as a demographic

Using public transportation
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The Definitional Paradox

• There is no single operational definition of
  disability (multiple sets of questions, linked to
  the different purposes of measurement, may be
  needed)
• Different operational definitions lead to
  different estimates
• The question you are trying to answer (the
  purpose) will determine which definition to use
• Need to understand the choices that are being
  made when a purpose and a definition are chosen
• Need to understand the choices that are being
  made when time, expenses and respondent burden
  limit number of questions

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The Disability Measurement Matrix

• Disability measurement is multidimensional like
  the phenomena itself
• Not every measure is appropriate for every
  purpose, nor is a single measure always
  sufficient
• The Disability Measurement Matrix links purpose
  with measurement (question characteristics)
• The Matrix is a tool to guide the choice of
  measures appropriate to the purpose of the data
  collection

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Matrix Components

• Part A represents the purposes for measurement
• Part B represents the substantive aspects of the
  questions (domain) that enhance the understanding
  of the concept of disability
• Part C represents the characteristics or format
  of the questions

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Part A Purposes

• Needs assessment / service provision
• Focus is on the individual who will be served by
  the program or product
• Trend monitoring
• Focus is to identify changes in prevalence rates
  of a particular indicator in the population that
  reflects policy concerns
• Equalization of opportunities
• Focus is on the population that are at risk for
  participation limitations and will benefit from
  civil rights legislation and programs

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Part B Conceptual components

• Conceptual components
• Body functions and structures
• Sample domain global mental functions
• Example of element to be operationalized
  consciousness
• Activities and participation
• Activities
• Sample domain mobility
• Example of element to be operationalized walking
• Participation
• Sample domain domestic life
• Example of element to be operationalized
  acquiring a place to live
• Environmental factors
• Sample domain products and technology
• Example of element to be operationalized
  products and technology for communication

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Part C Question survey characteristics

• Question characteristics
• Duration of a circumstance
• Response options
• Need for a standard reference
• Capacity or performance / presence of
  accommodations
• Question language
• Survey characteristics
• Space limitations
• Skip pattern
• Screener

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Application of matrix Example 1

• Purpose
• Monitoring trend in use of public transportation
  system
• Conceptual components
• Activity and participation
• Identify persons with limitations in community
  mobility
• Sample domains mobilitymoving around using
  transportation
• Question characteristics
• Dichotomous response
• Performance with use of adaptations at personal
  and system level

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Application of matrix Example 2

• Purpose
• Equal access to public transportation
• Conceptual components
• Activity and participation
• Identify persons at risk of unequal access to
  transportation due to limitations in basic
  activities
• Sample domains walking, vision, hearing,
  communication, etc.
• Question characteristics
• Scaled response
• Without use of assistance or special equipment

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Summary

• The purpose of disability measurement must be
  examined and understood
• Once purpose is determined, relevant domains of
  measurement must be selected
• Elements of each domain must be operationalized
• This will focus the conceptualization of
  disability being used