The Danish SF-36 Health Survey: translation and preliminary validity studies

This article reports on the Danish translation of SF-36 and discusses the procedures used for translation improvement, translation evaluation, and scale evaluation. We followed the standard procedures of the International Quality of Life Assessment (IQOLA) Project including forward and backward translation, independent assessment of translation quality, assessment of response-choice weighting through visual analogue scale (VAS) investigations, and psychometric testing of the translated questionnaire. We found that backward translation, independent quality assessment, and VAS studies provided useful information for translation improvement. The Danish SF-36 received a favorable translation evaluation by independent rating; however, interrater agreement was low. Preliminary validity studies generally supported the internal consistency and homogeneity of the Danish SF-36, and the questionnaire performed satisfactorily in distinguishing depressive patients from nonpatients. On the basis of this and other studies, we recommend use of the Danish SF-36 in research.