Translation and validation of EORTC QLQ-H&N 35 into Moroccan Arabic for ENT head and neck cancer patients in Morocco

Disease-specific quality of life (QOL) measures have enhanced the capacity of outcome measures to evaluate subtle changes and differences between groups. As many of the QOL measures have been developed in English, they require translation to ensure their usefulness in a multi-cultural and/or international society. Published guidelines provide formal methods to achieve cross-culturally comparable versions of a QOL tool. The aim of this study was to adapt the head and neck specific module of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-H&N 35 questionnaire) into Moroccan Arabic and to determine its psychometric properties. After translation, back translation and pretesting of the pre-final version, the translated version was submitted to a committee of professionals composed by otolaryngologists and epidemiologists. The psychometric properties were tested in patients with ENT cancer. Internal consistency was tested using Cronbach's alpha and the test-retest reliability using interclass correlation coefficients. Construct validity was assessed by examining item convergent and divergent validity. It was also tested using Spearman's correlation between QLQ-H&N 35 scales and EQ-5D. The study was conducted in 120 patients. The Moroccan version was internally reliable, Cronbach's alpha ranged from 0.71 for "trouble with social contact" to 0.94 for "senses impairment", indicating good internal consistency. Test-retest reliability was assessed using the intra-class correlation coefficient, which ranged from 0.64 for "speech trouble" to 0.89 for "physical activities". The instrument demonstrated a good construct and concomitant validity. We have developed a semantically equivalent translation with cultural adaptation of EORTC QLQ-H&N 35 questionnaire. The assessment of its measurement properties showed that it is quite reliable and a valid measure of the effect of cancer on the quality of life in Moroccan patients.