Translation and Cross-Cultural
Equivalence of Health Measures
Context: why are we interested?
1.
Multinational drug trials: Need to ensure products
are tested in a standard way in different countries.
2.
Cross-cultural research within countries
3.
International health studies (WHOQoL, etc.)
4.
Evidence-based medicine: how confident can I be
that results of a clinical trial overseas would apply
here?
Translation
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Simply translate an instrument and
administer it
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Differences in response interpreted as
differences in prevalence: assumes
equivalence of the measurement scale in
the 2 countries
Almost certainly inadequate
Translation + back translation
Issues to consider in translating an
instrument
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Do you wish to adapt the measure for a new
country, or make comparisons across countries?
Should it be a strict translation or an adaptation?
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Back-translation gives linguistic identity rather than
equivalence
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Example of long-term memory item in a dementia screen “In
what year did the first world war begin?”
In most countries the ‘official’ language differs from
the vernacular. Which do we use?
We often ignore linguistic variations within countries
Translation or cultural domination?
Beware hidden biases in whole idea of translation.
Consider a comment by Alexander Leighton
(circa 1955) :
He made “refinements and changes … here and
there in order to convey the meaning of the
English questions as accurately as possible…”
Why was this instrument chosen? Is the content truly
relevant in another culture?
Issues to consider - continued
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At least some of the content of most scales
is culture-specific (e.g., items in
Nottingham Health Profile were seen as
blasphemous in an Arabic country)
Was the scale developed on a particular
cultural group?
Verbal translation versus creating a cultural
equivalent.
Words & cultural concepts
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An etic approach to language (phonetic)
describes the physical properties of the
word, without referring to its functional
meaning: language
The emic approach takes account of the
context, meaning and purpose of a word:
concepts
Translation example: Friends
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“Does poor health prevent you from seeing
your friends?”
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Be careful: emic meaning of “friend” differs
in UK, US, and Australian forms of English
Even more differences between Ami(e),
Amigo and Freund
Relevance of Culture
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Culture shapes the way we think about health and
illness: it influences the attention we pay to
symptoms, our reactions to pain, etc.
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Expectations & definitions of feeling good, etc.
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It influences customary behaviours, relationships with
others, including people with clip boards &
questionnaires: the ‘questionnaire sophistication’ of
the group.
It affects the way we interpret the language used
in our questionnaires.
Level of abstraction
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Concepts can be:
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Abstract but general
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E.g., Happiness, Ability
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These terms probably apply in different cultures, but are
imprecise and subjective: their meaning may differ.
However, being subjective may be sufficient in itself:
perhaps a person’s subjective answer is inherently valid.
(Discussion point: does it matter if happiness means
slightly different things in different cultures?)
Concrete and specific

Number of hospital beds per capita
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You can compare these across cultures, but
They are very context-dependent so less cross-culturally
comparable.
Establishing Cross-Cultural Equivalence
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Are you using the same general measurement procedures?
Or, at least culturally equivalent approaches? (This could
mean using different words)
Item equivalence: items should mean the same thing to
people in one culture as in another
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And be similarly difficult. E.g. on FAS test, items with identical
meaning in French are not FAS, but T, N and P.
Response scale equivalence (e.g., is the distance between
“moderately severe” and “severe” the same in both
cultures? Will respondents feel equally comfortable with
responses like “Disagree strongly”?)
Conceptual or Functional Equivalence
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Is the theme being measured really a universal experience?
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Does this construct mean the same thing in both cultures?
(How do we know this?)
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Does it matter that a theme such as quality of life has a different
range in 2 cultures? Should it be measured relative to local
expectations, or in an absolute way?
Do the same cause-effect relations exist in each culture?

Does a similar situation lead to similar behaviours across cultures?
(E.g., sick enough to go to a doctor)
Developing cross-cultural measures
1.
Sequential approach
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2.
Simultaneous approach
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3.
Translate an instrument into another language
Conceptualize & develop measure in each culture
Choose a set of equivalent items that reflect the
same construct in different cultures
Core instrument plus culture-specific
additional components
Common strategies for ensuring
cross-cultural equivalence
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Direct translation and comparison
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Better translation techniques
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Multi-trait, multimethod matrix
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Item response theory methods
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Differential item functioning
Strategies, continued
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Response pattern method
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Factor analysis
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Multidimensional scaling
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Combined etic-emic approach
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Multi-strategy approach
Factor analysis
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Empirical analysis of how items relate to one
another
Shows how many concepts scale measures and
which items measure that scale
Confirmatory: must have theory about how items
go together
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Simultaneous factor analysis in different populations
Factor structure should be the same
Test whether data are similar to be called equal
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Same factor pattern-loadings
Same goodness of fit
Differential Item Functioning (DIF)
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Related to IRT theory
DIF = a difference in an item score between two groups who
are equal in overall ability (e.g. as indicated by equal total
scores)
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E.g. male & female difference in responses to sports played or
symptoms of depression
Uniform DIF = differences between groups at all trait levels. Nonuniform DIF = differences only at certain trait levels.
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Needed because tests can have matching factor structures and
still be biased.
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Example in Crane PK. Statistics in Medicine 2004;23:241.
DIF analyses
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Involves comparison of 2 or more groups
(e.g. different languages)
Step1: match people on ability (total score)
2nd step: for each score group, compare
performance of reference and focal group
on each item. (Reference is usually the original
language)
Two types of DIF
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Uniform
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Difference in item difficulty between
reference and focal group
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Item may be more difficult for one group (perhaps
translation problem?)
Non-uniform
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Difference in item discrimination parameter
between reference and focal group
Translation & cultural equivalence
suggestions
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Plan cross-cultural applications from the outset
Consider relevance of quality of life carefully: omit?
Avoid questionnaires!
Use ‘DIF’ analyses
Run within-country analyses
Develop measures within each country
Search for a core set of universal items (e.g. WHOQoL)
Make sure the values are explicit