According to international guidelines, the translation of the KIDSCREEN draft questionnaire included a forward-backward-forward translation procedure with harmonisation processes.
Each participating centre translated the items into the language of the target population, using a standardised translation methodology. To ensure cross-cultural harmonisation, a standardised translation procedure was followed according to international cross-cultural translation guidelines (WHOQol Group, 1993; IQOLA, 1991). The first step employed a forward-backward-forward translation technique. In each country the original English pilot draft was translated twice by two independently working translators into the respective language (national forward translations). Hereafter, the items of the two independent versions were compared in order to generate a single corrected reconciled version of each item (national reconciled forward translations). The items of the national reconciled forward translations were then back-translated into English (national backward translation) in order to be subsequently compared with the items of the original English pilot draft. This comparison was designed to provide final versions of items for the national questionnaires (national final forward translation).
To reach cross-cultural harmonisation, conceptual equivalence of the respective national final forward translations was checked on an international basis. A telephone conference was held to resolve inadequate translations and discrepancies between alternative versions. A pre-test followed by cognitive interviews took place in the respective countries to ensure the feasibility of the pilot questionnaire. It was proved that children younger than 8 could read, understand and answer all the items without problems. Agreement on final item formulation was then reached in a meeting in which all countries participated.