During the interview, the respondents complete the questionnaire, and then answer a series of open-ended questions on its content and explain what they think each item means in their own words.
The process also ensures multi-lingual harmonization of the translations, by making sure that the questionnaire is understood in the same way by target populations across all language groups, thus ensuring that the resulting quantitative data can be compared across language groups.
An alternative method of conducting linguistic validation is to ask a clinician who specialises in working with the target population to review the text, to ensure that it is clearly understandable.
However, regulatory authorities consider it preferable to validate measures through the above-mentioned cognitive debriefing with the patients in the target population where possible, and clinician reviews are more usually reserved for clinician-reported measures, or for particular circumstances in which testing with patients in the target population is particularly problematic (Wild et al.
[3] Some companies use the term 'linguistic validation' to refer to the entire process for the translation of PRO measures as described in the 'Principles of Good Practice' (Wild et al. 2005),[3] and the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) Task Force report (Wild et al. 2009),[4] even if this process does not include patient interviews or a clinician review.