Translation and CrossCultural Equivalence of Health Measures

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Translation and Cross-Cultural Equivalence of
Health Measures
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Context

• Multinational companies international drug
  trials
• Cross-cultural research within Canada
• International health studies
• General sense of globalization but does this
  downplay differences?

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Relevance of Culture

• Culture shapes the way we conceive of health and
  illness
• Influences customary behaviours, relationships
  with others
• Influences relative values of symptoms
• Reactions to pain, etc.
• Expectations definitions of feeling good, etc.
• Questionnaire sophistication of the group

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Level of abstraction

• Concepts can be
• Abstract and general
• Happiness, Ability
• Concrete and specific
• Number of hospital beds per capita
• More abstract concepts
• Applicable to different cultures, but
• More imprecise
• Specific concepts
• Less cross-culturally applicable
• More context dependent

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Types of Cross-Cultural Equivalence

• Is it operationalized in same way? (Same general
  measurement procedures)
• Item equivalence Items should mean the same
  thing to people in one culture as in another
• Scalar equivalence (E.g., is the distance between
  moderately severe and severe the same in both
  cultures?)

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Requirements for cross-cultural equivalence

• Conceptual/functional
• Equivalence in construct operationalization
• Item equivalence
• Scalar equivalence
• Hierarchical must have first before second

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Conceptual/FunctionalEquivalence

• Is there a universal situation?
• Does construct mean the same thing in both
  cultures?
• Can goal of behaviour be identified?
• Are same antecedent-consequent relations
  demonstrable across cultures?
• Does same situation result in same behaviour
  across cultures?

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Equivalence in operationalization

• Is it operationalized in same way?
• Same procedure
• E.g. measuring disability with
• Questions on self-care
• Measuring visual impairment with
• Snellen chart

9
Item equivalence

• Measured by same instrument
• Items should mean the same thing to people in one
  culture as in another
• E.g. on FAS test, items with identical meaning in
  French are not FAS, but T, N and P
• No ifs, ands, or buts

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Scalar Equivalence

• Measured on the same metric
• Numerical value on scale has same degree of
  intensity or magnitude of the construct
• E.g. is the distance between 6 (moderately
  severe) and 7 (severe) the same in both cultures?

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Developing cross-cultural measures

• Sequential approach
• Translate an instrument into another language
• Simultaneous approach
• Conceptualize develop measure in each culture
• Set of equivalent items that reflect the same
  construct in different cultures
• Core instrument plus culture-specific additional
  components

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Strategies for ensuring cross-cultural equivalence

• Direct translation and comparison
• Better translation techniques
• Multi-trait, multimethod
• Item response theory methods
• Differential item functioning

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Strategies continued

• Response pattern method
• Factor analysis
• Multidimensional scaling
• Combined etic-emic approach
• Multi-strategy approach

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Methods for assessing equivalence

• Factor analysis
• 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
• Simultaneous factor analysis in different
  populations
• Factor structure should be the same
• Test whether data are similar to be called equal
• Same factor pattern-loadings
• Same goodness of fit

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Differential item functioning

• Related to IRT theory
• Needed because tests can have matching factor
  structures and still be biased
• DIF analyses
• Compare reference and focal groups
• In translation from English to French, English
  reference and French focal

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Differential Item Functioning

• DIF a different in item score between two
  groups who are equal in ability.
• First step match on ability (total score)
• Internal test of item bias
• 2nd step for each score group, compares
  performance of reference and focal group on each
  item

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Two types of DIF

• Uniform
• Difference in difficulty between reference and
  focal group
• Item may be more difficult for one group
• Non-uniform
• Difference in discrimination between reference
  and focal group

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When you find DIF or non-factorial equivalence

• Study reasons why
• Content experts
• Review item wording, translation, cultural
  meaning.

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Translation

• Simply translate instrument and administer it
• Simple tests of difference assumes scalar
  equivalence
• Translation-back translation

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Issues to Consider

• Goal to adapt measure for a new country, or to
  make comparisons across countries?
• Translation or adaptation? Back-translation
  gives identity rather than equivalence
• In most countries the official language differs
  from the vernacular. Which do we use?
• We still know little about effect of linguistic
  variations within countries

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Issues - continued

• Why was this instrument chosen? Are these
  features relevant in another culture?
• At least some of the content of most scales will
  be culture-specific (e.g., some of NHP seen as
  blasphemous in Arabic countries)
• Was the scale developed on a particular cultural
  group?

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Quality of Life

• Quality of life is subjective value-specific
• Invented in the USA not universal?
• Definition will at least vary across cultures
  (naïve enthusiasm for QoL)
• Handicap reflects impairment environment, so
  measures may perform differently in different
  environments

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Translation, or Domination?

• with refinements and changes introduced here
  and there in order to convey the meaning of the
  English questions as accurately as possible
  (A. Leighton)

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Words Concepts

• An etic approach (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 the word concepts

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Translation Example

• Does poor health prevent you from seeing your
  friends?
• Meaning of friend differs in UK, US, and
  Australian English
• Even more differences between Ami(e), Amigo and
  Freund

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Suggestions

• 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
• Seek core set of universal items (WHO QoL)
• Make sure the values are explicit