6^th^ Meeting of the Washington Group on Disability Statistics

Kampala, Uganda

October 10-13, 2006

**[Summary of pre-test results for WG short set of questions:
MOBILITY]{.underline}**

**Introductory phrase:**

The next questions ask about difficulties you may have doing certain
activities because of a HEALTH PROBLEM.

**[Question on mobility]{.underline}**

Do you have difficulty walking or climbing steps?

a.  No- no difficulty

b.  Yes -- some difficulty

c.  Yes -- a lot of difficulty

d.  Cannot do at all

[Summary of pre-test results]{.underline}:

In the cognitive tests, only 81 of the cases (out of 852) fell into the
"problematic" group of response patterns for the mobility question. The
majority of cases fell into pattern "I" (48 of the 81 problematic
responses) where respondents answered "no" to the WG question but "yes"
to one or more of the extended questions[^1]. Most of these respondents
reported only some difficulty on the extended questions suggesting that
they may not consider their impairment to be serious enough to report in
the general WG question. Alternatively, the extended questions may be
detecting aspects of mobility that differ from walking (such as problems
with sitting, stooping or standing) or that are more specific than the
WG question (such as difficulty walking long distances).

Data from the field test indicated more reports of difficulty moving
inside the home (extended question) compared to the WG question also
suggesting that the extended questions may be detecting different
aspects of mobility than the WG question. In field tests, there was
better correspondence between the WG question and extended questions
that were more closely related to walking (such as the question about
walking a long distance). Data from Vietnam (the largest field test)
showed good (but not very good) correspondence between the degree of
difficulty reported on the WG question compared to the extended
questions. Responses usually differed by only one level (for instance "a
lot of difficulty" on the detailed question and "some difficulty" on the
WG question).

Because of these discrepancies, there was discussion about whether to
make the WG question more specific (i.e. add a clear reference to
distance). Concern was raised that this would make the question less
comprehensive and would introduce error because of the additional
complexity. This generated a more general discussion about the necessary
level of generality / specificity for all 6 WG questions. After much
discussion, it was agreed that some error is acceptable and to be
expected. Based on the pre-test results, the overall level of error with
the WG questions was small and bias in responses because of contextual
differences across countries did not appear to be a problem. It was
agreed that increasing the specificity of the questions would not be
beneficial, particularly in a Census format and given cultural and
contextual differences across countries.

Overall, the question on mobility was well understood by respondents.
Since there was a relatively small number of problematic cases, and
correspondence between the WG question and the extended questions was
relatively good on the field tests, the results were considered positive
and there were no recommendations for revision of this question.

[^1]: Extended questions: (i) *Do you use any kind of equipment, such as
    a wheelchair, walker or cane, to help you get around? Do you have
    difficulty* (ii) *going outside of your home?* (iii) *walking a long
    distance such as a kilometer (or a mile)? By yourself and not using
    aids, do you have any difficulty* (iv) *walking for a quarter of a
    mile (about 2 or 3 blocks)?* (v) *walking up ten steps without
    resting?* (vi) *standing or being on your feet for about 2 hours?*
    (vii) *sitting for about 2 hours?* (viii) *stooping, crouching or
    kneeling?*