Fig. 1.

Translation process. In Phase 1 (forward translation), 2 independent forward translations (English to Norwegian) were produced (Forward version A1 and Forward version A2). A pooled Norwegian version (Forward version B) was then produced based on the 2 independent forward translations. Phase 2 (backward translation) was performed from Norwegian to English. Comparison between the backward version and the original source questionnaire yielded Forward version C. In Phase 3 (validation), Forward version C was tested (validated) on a patient sample, obtaining Forward version D. In a final step (harmonization), forward versions were compared with each other and the original source questionnaire and matched to ensure conceptual equivalence. After final proof reading, the final version of the questionnaire in Norwegian was obtained. Adapted with permission from Health Qual Life Outcomes. 2003;1:70.²²