Linguistic validity means that different language versions of an instrument such as a questionnaire are conceptually equivalent in each of the target countries. (1-3) Such questionnaires should be understood and practically performed in the same way. Linguistic and cross-cultural aspects must be taken into account as well the concept related to the questionnaire involved. Linguistic validity can be reached by means of a forward-backward translation procedure.

The Maastricht-Antwerp research group performed a linguistic validation procedure as to the Gut Feelings Questionnaire in 2010-2011. The entire procedure that the group followed in translating the Dutch Gut Feelings Questionnaire into English met the standardization criteria found in the international literature, (1-8) and on some websites (see below).

Forward-backward translations

1)  Two native-speaking (BE) translators with medical knowledge separately translated the questionnaire after receiving information about the goal of the questionnaire and the way it will be used in research. They were invited to add comments as needed.

2)  Two native-speaking Dutch language translators with medical knowledge were asked to provide separate backward translations. They were also invited to add comments as needed.

 Consensus

3)  Two members of the Maastricht research group prepared a first draft for a consensus translation, putting all the differences and questions in an extended table.The four translators were separately asked to read this first consensus carefully, including all the comments on the table, and to add their opinions to this table. Afterwards, the same two members of the research group adjusted the consensus and collected all the remaining questions and translation problems in a new table. They then held a telephone meeting with all four translators, in which all problems were discussed. One of the Maastricht research group acted as a chair, while the other focused on all linguistic items, and a secretary made a report of the discussion. At the end of the meeting, almost a complete consensus was reached. Only the wording of item 10 of the questionnaire had to be reviewed before a decision could be made.

 Cultural check

4)  The second draft of the translation was sent to all translators. After adjusting minor points, we sent this text to ten British GPs (native speakers) and ten US GPs (native speakers) asking them to check for grammatical errors and cultural misunderstandings. Their comments were collected in the third table. The four translators studied the comments and gave their final judgment.

Conclusion

5)  After considering the translators’ recommendations, the two members of the Maastricht research group finally determined the definitive text (BE version and AE version) of the questionnaire. During the whole procedure, the Maastricht research group was informed about all steps we took, and they agreed with the final results.

(1) Acquadro C, Conway K, Hareendran A, Aaronson N. Literature review of methods to translate health-related quality of life questionnaires for use in multinational clinical trials. Value Health 2008 May;11(3):509-21.

(2)  Acquadro C, Conway K, Giroudet C, Mear I. Linguistic validation manual for patient-reported outcomes (PRO) instruments. Lyon: MAPI Research Institute; 2004.

(3)  Streiner DL, Norman GR. Health Measurement Scales. A practical guide to their development and use. 3 ed. Oxford: Oxford University Press; 2006.

(4)  Koller M, Aaronson NK, Blazeby J, Bottomley A, Dewolf L, Fayers P, et al. Translation procedures for standardised quality of life questionnaires: The European Organisation for Research and Treatment of Cancer (EORTC) approach. Eur J Cancer 2007 Aug;43(12):1810-20.

(5)  Beaton DE, Bombardier C, Guillemin F, Ferraz MB. Guidelines for the process of cross-cultural adaptation of self-report measures. Spine (Phila Pa 1976 ) 2000 Dec 15;25(24):3186-91.

(6)  Herdman M, Fox-Rushby J, Badia X. A model of equivalence in the cultural adaptation of HRQoL instruments: the universalist approach. Qual Life Res 1998 May;7(4):323-35.

(7)  Herdman M, Fox-Rushby J, Badia X. ‘Equivalence’ and the translation and adaptation of health-related quality of life questionnaires. Qual Life Res 1997 Apr;6(3):237-47.

(8)  MAPI Institute. http://www.mapi-institute.com/linguistic-validation . 1-9-2011.

See the World Health Organisation:

http://www.who.int/substance_abuse/research_tools/translation/en/

And an article in The International Journal for Translation and Interpreting Research:

http://trans-int.org/index.php/transint/article/viewFile/38/55