Validity and reliability of a french version of the olfactory disorders questionnaire

Objective To validate a French version of the Olfactory Disorders Questionnaire (Fr-ODQ). Methods Patients with olfactory disorder (OD) and controls were enrolled from two medical centers. Individuals completed the Fr-ODQ and the French version of the sinonasal outcome tool-22 (SNOT-22). The extended Sniffin'Sticks procedure was used to test odor Threshold, Discrimination, and Identification (TDI). Cronbach's alpha was used to measure the internal consistency of Fr-ODQ. The reliability and the external validity were evaluated through a test-retest approach and by correlating Fr-ODQ and SNOT-22 scores. Results Eighty-nine patients with OD and 65 healthy individuals completed the evaluations. The Cronbach's alpha was 0.827, reporting adequate internal consistency. The test-retest reliability was high (r(s) = 0.944, p = 0.001). The external validity was adequate regarding the significant correlation between Fr-ODQ and SNOT-22 (r(s) = 0.498; p = 0.001). Patients with OD reported a significant higher score of Fr-ODQ than healthy individuals (p < 0.001), indicating a high internal validity. The baseline Fr-ODQ significantly improved after 3-month olfactory training, which corroborated the improvement of TDI scores. Conclusion The Fr-ODQ is the first patient-reported outcome questionnaire validated for French speaking patients. Fr-ODQ is reliable and valid for the evaluation of the olfactory dysfunction and the related impact on quality of life of French-speaking patients.