This document provides an overview of the World Health Organization Disability Assessment Schedule II (WHODAS II), which is a standardized method for measuring health and disability developed from the International Classification of Functioning, Disability and Health (ICF). The WHODAS II was created to address limitations of prior models and provides a practical, reliable and valid tool for assessing functioning across domains like cognition, mobility, self-care, relationships, life activities, and participation. It has good psychometric properties and allows comparison across cultures and conditions. Administration involves rating difficulty with various tasks on a scale of none to extreme over the prior 30 days.

1. Assessing Disability – World Health
Organization Disability Assessment
Schedule II (WHODAS II)
Mr Vaikunthan Rajaratnam
MBBS(Mal),AM(Mal),FRCS(Ed),FRCS(Glasg),FICS(USA),MBA(USA),
Dip Hand Surgery(Eur),PG CertMedEd(Dundee),FHEA(UK),AFFST(Ed),FAcadMEd(UK).
Senior Consultant Hand Surgeon
Alexandra Health, SINGAPORE

2. Disability and Damage
Injury/Illness Treatment Intervention Outcome

3.  43 year-old female, right-handed, cook
Traumatic amputation of right thumb and index finger


4. Unreplantable thumb

5. Underwent right thumb reconstruction
with right big toe osteoplastic wrap-
around flap 1 week post-injury, after
counseling and consenting

6. Toe wrap based on
dorsalis pedis

8. Defining
•
Impairment: any loss or abnormality of psychological, physiological
or anatomical structure or function.
•
Disability: any restriction or lack (resulting from an impairment) of
ability to perform an activity in the manner or within the range
considered normal for a human being.
•
Handicap: a disadvantage for a given individual that limits or
prevents the fulfilment of a role that is normal
•
As traditionally used, impairment refers to a problem with a
structure or organ of the body; disability is a functional limitation
with regard to a particular activity; and handicap refers to a
disadvantage in filling a role in life relative to a peer group.
World Health Organization (1980) in The International Classification of
Impairments, Disabilities, and Handicaps:

9. International Classification of
Functioning, Disability and Health
(ICF)
• classified from body, individual and societal
perspectives
• measuring health and disability at both
individual and population levels
• shifting the focus from cause to impact
• the social aspects of disability
– http://apps.who.int/classifications/icfbrowser/

10. Psychometrics
construction and validation of measurement
instruments such as questionnaires, tests, and
personality assessments

11. Classical test theory
• reliability and validity.
– Pearson correlation
coefficient, and is often
called test-retest
reliability.
– index of reliability
is Cronbach's α
• concurrent
validity; predictive
validity, construct
validity, Content validity

12. WHODAS II
• ISBN 978 92 4 154759 8
• (NLM classification: W 15)
• © World Health Organization 2010
• http://p.ideaday.de/104.2/icf/en/index.html

13. WHODAS II
• generic assessment instrument
• standardized method for measuring health
and disability
• developed from a comprehensive set of
International Classification of
Functioning, Disability and Health (ICF)
• Cross cultural applicability, utility, reliability
and validity

14. Why is disability assessment
important?
• “there are no
diseases, but
patients”
• There are no
disabilities but
people with
problems that
affect their lives

15. Why develop a method to assess
disability?
• “a decrement in each functioning domain”
– Body, person and society
• International Classification of
Functioning, Disability and Health (ICF) –
impractical for daily use
• WHODAS 2.0 – practical, reliable and valid

16. Why learn and use a disability
measure?
• patient’s needs
• level of care
• outcome of the condition
• length of hospitalization
• receipt of disability benefits
• work performance
• social integration

17. Disability assessment
• identifying needs
• matching
treatments and
interventions
• measuring
outcomes and
effectiveness
• setting priorities
• allocating resources.

20. Why use WHODAS 2.0?
• sound theoretical underpinnings
• good psychometric properties
• numerous applications
• direct link to the ICF
• Cross-cultural comparability
• Ease of use and availability

21. WHODAS 2.0
practical, generic assessment instrument measuring health and disability
• 1: Cognition – understanding and communicating
• 2: Mobility – moving and getting around
• 3: Self-care – attending to one’s
hygiene, dressing, eating and staying alone
• 4: Getting along – interacting with other people
• 5: Life activities – domestic
responsibilities, leisure, work and school
• 6: Participation – joining in community
activities, participating in society.

22. WHODA II contd
• common metric
• generic measure
• possible to design and monitor interventions
• etiologically neutral
• focus directly on functioning and disability
• full version has 36 and the short version 12
questions

24. Bio psychosocial model of ICF
• disability is multidimensional
• interaction between attributes of an individual
and features of the person’s physical, social
and attitudinal environment

25. WHODAS and WHOQOL
• WHODAS 2.0 measures functioning (i.e. an
objective performance in a given life
domain), while WHOQOL measures subjective
well-being (i.e. a feeling of satisfaction about
one’s performance in a given life domain).
• Does vs Feel

27. 36-item version
• interviewer-administered, self-administered
and proxy-administered
• most detailed
• 20 minutes.

28. 12-item version
• brief assessments of overall functioning
• interviewer-administered, self administered
and proxy-administered.
• explains 81% of the variance of the 36-item
version
• five minutes.

29. 12+24-item version
• hybrid of the 12-item and 36-item versions
• Based on positive responses to the initial 12
items, respondents may be given up to 24
additional questions
• administered by interview or computer-
adaptive testing (CAT).
• 20 minutes.

30. Psychometric properties
• Test–retest reliability and internal consistency
- Cronbach’s alpha levels 0.98
• Most questions fitted in their assigned
domains, confirming the unidimensionality of
domains
• summary change scores were unaffected by
sociodemographic factors
• Face , construct and concurrent validity

31. Practical aspects of
administering and scoring
• Privacy
• • frame 1 – degree of difficulty
• • frame 2 – due to health conditions
• • frame 3 – in the past 30 days
• • frame 4 – averaging good and bad days
• • frame 5 – as the respondent usually does the
activity
• • frame 6 – items not experienced in the past 30
days are not rated.

32. Frame of reference 1 – degree of
difficulty
• • increased effort
• • discomfort or pain
• • slowness
• • changes in the way the person does the
activity.

33. Frame of reference 2 – due to health
conditions
• diseases, illnesses or other health problems
• • injuries
• • mental or emotional problems
• • problems with alcohol
• • problems with drugs.

34. Scoring
• “none” (1),
• “mild” (2)
• “moderate” (3),
• “severe”(4) and
• “extreme” (5)
Simple vs complex scoring

35. • Questions A1–A5: Demographic and background
information
1: Cognition – understanding and communicating
• 2: Mobility – moving and getting around
• 3: Self-care – attending to one’s hygiene, dressing, eating
and staying alone
• 4: Getting along – interacting with other people
• 5: Life activities – domestic responsibilities, leisure, work
and school
• 6: Participation – joining in community
activities, participating in society.
• Questions F1–F5: Face sheet

47. THANK YOU