French adaptation and validation of the SinoNasal Outcome Test (SNOT)-22: a prospective cohort study on quality of life among 422 subjects

OBJECTIVES: ENT surgeons are facing an ever-increasing demand to demonstrate their efficacy. The 22-item Sino-Nasal Outcome Test (SNOT-22) is a fully validated and easy-to-use outcome measure in rhinology. Our goal was to translate and validate the SNOT-22 in a cohort of 422 French-speaking subjects. DESIGN, SETTING AND PARTICIPANTS: The French version of the SNOT-22 was obtained by forward and backward translations by six independent interpreters. Five experienced rhinologists compared the translations to each other, and a group of 12 naive patients selected the most appropriate translation of each item. To evaluate this questionnaire, we conducted a prospective cohort study on 376 rhinological patients and 46 healthy volunteers in three University-affiliated teaching Hospitals. MAIN OUTCOME MEASURES: Reproducibility (test-retest reliability), internal consistency, known-group differences, responsiveness to treatment, validity and correlation to other clinical instruments (visual analogue scale, Nasal Obstruction Symptoms Evaluation score and Lund-Mackay score). RESULTS: The test-retest reliability coefficient was 0.78, indicating a good reliability when administering the instrument on two different occasions. The internal consistency was high with a Cronbach's α value of 0.93. Our questionnaire was able to detect differences between rhinological patients and control subjects (P < 0.0001) and improved significantly after nose and sinus surgery (P < 0.0001), indicating a good responsiveness. There was a relative correlation with visual analogue scale and Nasal Obstruction Symptoms Evaluation (NOSE) score, but no correlation with Lund-Mackay score. CONCLUSION: The SNOT-22 is a reliable and valid tool to assess quality of life in French-speaking patients and correlates well with known indices of disease severity