Once upon a time, probably during the second semester of 2005, I faced an interesting questionnaire aiming to measure depression, anxiety and stress named the Depression Anxiety and Stress Scale (DASS). I was supposed to use this instrument in the patients that I would recruit later for a randomised trial on back pain... I started reading the instrument enthusiastically, but half-way through I got puzzled with item number 13: “I felt down hearted and blue”... at that moment in time I asked myself “down hearted and blue???”... In Brazil (i.e. my country) if you say to someone that you are “blue” people will come to two conclusions: 1) you belong to the Smurfs cartoon, or 2) you are a strong Cruzeiro supporter (Cruzeiro is one of the most traditional football teams in Brazil).
It would be possible to use the same instrument across the globe if all the people of the world spoke the same language, they felt and thought the same way, and their lifestyles were much the same. Thankfully the world is a much more interesting place than this and to accommodate this variety it is necessary for researchers to adapt the original questionnaire so that it is comprehensible and relevant in a new setting. This process is called cross-cultural adaptation.
Cross-cultural adaptation seems simple, but it is actually not. Some questions from questionnaires developed in different countries could not be applicable to new cultures, some words have no direct translation for the new language, and maybe some questions just don’t make any sense in the new country/language/culture. For example, a systematic review on the international versions of the McGill Pain Questionnaire observed that the number of items of this instrument ranged from 29 to 78 depending of the language/culture that the questionnaire was adapted for (1). Conversely, the items from the Roland Morris Disability Questionnaire are quite stable in most of the adapted languages (2).
Cross-cultural adaptation of existing questionnaires would enable comparisons of different populations and permit the exchange of information across cultural and linguistic barriers. This procedure also enables the pooling of data from trials performed in different countries. Everything looks great, but cross-cultural adaptation procedures only makes sense if the clinimetric properties of the new instrument are tested... but this is another theme, for another post.
See you soon, até logo, hasta la vista, Bis bald, Ci vediamo, Hasta pronto, À bientôt (hopefully we cross-culturally adapted this properly)
1. Costa LCM, Maher CG, McAuley J, Costa LOP. Systematic review of cross-cultural adaptations of McGill pain questionnaire reveals a paucity of clinimetric testing. J Clin Epidemiol2009;62(9):934-43.
2. Costa LOP, Maher CG, Latimer J. Self-report outcome measures for low back pain - Searching for international cross-cultural adaptations. Spine2007;32(9):1028-37.