ABSTRACT
Objective[s]: Valid and reliable data collection requires valid and reliable tools [questionnaires]. In using questionnaires in other languages, translation and psychometrics to make them compatible with target culture gain the first priority. The aim of this study was to translate KINDL questionnaire [for measuring quality of life in school-age children] to Farsi and to perform its psychometric evaluation
Methods: In this methodology study, after permission from developers of KINDL questionnaire, it was translated in 7 stages. Its English version was first translated to Farsi. Different early translations were then unified into one Farsi version. The final product was then translated back into English with revision, correction and finalization. For measuring psychometric, content validly, criterion validity and reliability by test-retest methods were used. First the KINDL questionnaire was translated and then psychometric was measured. Content validity index [CVI] of the questionnaire was measured based on the "relevance", "clarity", and "simplicity" on a four point scale
Results: The results showed that content validity index was more than %75 for all questions. In addition, the results of criterion validity of KINDL questionnaire and "Quality of Life Questionnaire for Children with Asthma" showed a significant, linear and positive relationship between the scores of the two questionnaires by Spearman statistical test. In addition, test-retest results showed a high correlation between the different domains of the questionnaire
Conclusion: Foreign questionnaires should be translated by expert people and made compatible with the target culture of each country. Researchers should be aware of this important point when they apply questionnaires from other countries. In this research, content validity index, criterion validity and reliability of KINDL questionnaire were measured and approved. Thus, it can be concluded that the questionnaire is suitable to measure quality of life in children