disability models and measures -...
TRANSCRIPT
Disability Models and Measures
Sophie Mitra
Fordham University
Conference: Improving the measurement of
disability and the physical access of the
disabled: Lessons from international experience,
February 10, 2012
Moscow, 27 September 2011 1
Part 1. Models used to Define Disability
- The Medical Model
- The Social Model
- The Nagi Model
- The ICF (International Classification of
Functioning, Disability and Health)
2
The Medical (or Bio-Medical) Model
The medical model considers disability as a problem of the individual that is directly caused by a disease, an injury or other health conditions.
The medical model locates the problem with the person. A person is in the „sick role‟ (Parsons, 1975).
This model is strongly normative.
The major concern at the political level is to provide health care and rehabilitation services.
3
The Social Model
Disability is not a problem of the individual, it is a
problem created by the social environment and
requires social change.
This model has many different versions. We review
briefly below two versions.
The UK social model: At the heart of this model
lies societal oppression (Oliver, 1990).
4
The Social Model (Cont.)
The oppressed minority model. Persons with
disabilities face discrimination and segregation
through barriers in the environment. Their
experiences are therefore perceived as similar to
those of an oppressed minority group.
Social inequalities encountered by persons with
disabilities are considered as similar to those
encountered by other minorities (Hahn, 2002, p.
171).
5
The Nagi Model
The Nagi model is widely used in the economics of
disability field. It identifies functional limitations as
the restrictions that impairments impose on the
individual‟s ability to perform the tasks of his or her
roles and normal daily activities.
Disability is a social construct.
For instance, a 12-year old girl with mental
retardation does not attend school, she stays home
with her parents helping with household chores.
6
The ICF model
Health condition
Body Functions
and Structures
Activities Participation
Personal
Factors
Environmental
factors
7
Disability under the Capability Approach:
Disability has been defined in terms of capability or functioning deprivation (Burchardt 2004; Mitra 2006; Morris 2009; Terzi 2005; Welch 2007)
Disability occurs when an individual is deprived of practical opportunities or functionings as a result of an impairment or health condition.
8
The Capability Approach is a holistic approach
It accounts for the variety of factors that may lead to disability.
In particular, the Capability Approach recognizes that poverty
can be the cause of disability.
9
Part 2. Disability Measures
• Disability is difficult to measure.
• There is no gold standard measure.
• Disability measures vary depending on
research and policy objectives.
10
Disability Measures (Cont.)
I focus on disability measures that use
household survey or census data with
questions on:
Impairments.
Functional limitations.
Activity limitations.
A combination of the above.
11
Impairment Measures
Impairment measures of disability focus on
the presence of impairment intrinsic to the
individual.
For example, individuals may be queried
about blindness, deafness, mental retardation,
stammering and stuttering, complete or
partial paralysis.
12
Functional Limitation Measures
Functional limitations refer to difficulties
experienced with particular bodily functions
such as seeing, walking, hearing, speaking,
climbing stairs, lifting and carrying.
The above two measures of disability,
impairments and functional limitations
measure disability as per the medical model
and capture problems in body functions and
structures under the ICF.
13
Activity Limitations Measures
Activity limitations are limitations in activities of
daily living (ADL) such as bathing or dressing.
Activity limitations may also include participation
limitations in major life activities such as going
outside the home, work or housework for working
age persons, and school or play for children. This
measure may be considered to capture disability as
per the social model as well as the activity
limitations and participation restriction under the
ICF.
14
Different measures lead to very different prevalence estimates
Chile is an interesting case where estimates are available for
both impairment and activity limitation measures. The
impairment prevalence rate is almost 10 times lower at 2.2%
than the activity limitation rate at 21.7% (IDRM 2004).
In South Africa, estimates vary from a low of 3.7% in the
1999 October Household Survey, to a high of 12.8% in the
National Health and Population Survey where chronic
illnesses were counted as disabilities (Emmett (2006)).
CASE (1999) is the only study specifically designed to
measure disability prevalence and assess the well being of
PWDs. In this study, in 1997, disability prevalence stood at
5.9%. 15
Examples of disability questions:
India NSS 58th 2001: A person is considered
disabled “if the person has restrictions or lack of
abilities to perform an activity in the manner or
within the range considered normal for a human
being.”
South Africa GHS 2010 „Is the person limited in
his/her daily activities at home, at work or at school
because of a long-term physical or mental condition
lasting six months or more?‟
16
Examples of disability questions (Cont.):
India Census 2001:“If the person is
physically/mentally disabled, give appropriate code
number from the list below: in seeing, in speech, in
hearing, in movement, mental.”
17
Washington Group Short
Disability Measure
18
Identification of persons with disabilities:
Disability score and cutoff
e.g. WHO-World Bank (2011)
• Challenges in calculating a score
• Challenges in setting the cutoff
19
Identification of persons with disabilities for a given measure
(Cont):
Use of self-reported severity:
for instance, persons reporting severe or
extreme limitations are identified as having a
disability (Mitra, Posarac & Vick 2011;
Loeb, Eide & Mont 2008)
Note: Mild and moderate limitation self reports
are not as reliable as severe/extreme
(Lafortune et al 2007; Miller et al 2010).
20
Main sources
IDRM (2004), Regional Report of the Americas, International Disability Rights Monitor, International Disability Network, Chicago.
Lafortune G., G. Balestat and the Disability Study Expert Group Members (2007) Trends in Severe Disability among Elderly People: Assessing the Evidence in 12 OECD Countries and the Future Implications. OECD Health Working Paper 26.
Loeb M E, Eide A H, Mont D (2008) Approaching disability prevalence: the case of Zambia. European Journal of Disability Research. 2, 32 - 43.
Miller, K., D. Mont, A. Maitland, B. Altman, and J. Madans. (2010). “Results of a Cross-national Structured Cognitive Interviewing Protocol to Test Measures of Disability.” Quality and Quantity 45(4): 801-815, DOI: 10.1007/s11135-010-9370-4.
Mitra, S. (2006) The Capability Approach and Disability, Journal of Disability Policy Studies, 16, No. 4, pp. 236-247.
Mitra, S., Posarac, A. and Vick, B.. Disability and Poverty in Developing Countries: a Snapshot from the World Health Survey (long version:World Bank Social Protection Working Paper series 1109).
WHO and World Bank (2011). World Report on Disability. Geneva: World Health Organization and World Bank.
21
