Validity and Reliability of the French Olfactory Disorders Questionnaire-10

Importance Most French Olfactory Questionnaires are time consuming, which may affect the patient participation. Objective To validate a short French version of the Olfactory Disorders Questionnaire (Fr-ODQ). Design Prospective controlled study. Setting Multicenter study. Participants Patients with long-lasting olfactory dysfunction (OD) treated with platelet-rich plasma into the olfactory clefts and asymptomatic subjects. Intervention Development and validation of a short ODQ. Main Outcomes Individuals completed the full Fr-ODQ. The Threshold, Discrimination, and Identification (TDI) test was performed in OD patients. A combined statistical analysis was performed to determine the most informative items of the Fr-ODQ to develop a shorter version. The internal consistency was determined with Cronbach’s alpha. The reliability and external validity were evaluated through a test-retest approach and by correlating with the Fr-ODQ. Both the minimal clinically important difference (MCID) and the threshold of the short ODQ version were determined. Results A total of 263 patients (173 [65.8%] females) and 129 controls (92 [71.3%] females) completed the evaluations. The mean age of patients was 51.2 ± 15.3 years. The mean duration of OD was 42.4 ± 54.3 months. The biostatistical models selected 10 essential items composing the Fr-ODQ-10. The baseline Fr-ODQ-10 was significantly correlated with the TDI ( r s = 0.228; P = .001) and the Fr-ODQ ( r s = 0.875; P = .001), demonstrating high external validity. Fr-ODQ-10 was significantly lower in controls compared to OD patients ( P = .001), highlighting high internal validity. The internal consistency was good (α = .796). The external consistency was adequate, with significant correlations between the test-retest Fr-ODQ-10. The Fr-ODQ-10 significantly decreased from baseline to 4 months post-treatment. A Fr-ODQ-10 score >7.5 was considered abnormal (sensitivity: 84.8%, specificity: 84.2%). The MCID of Fr-ODQ-10 was established at >3. Conclusion and Relevance The Fr-ODQ-10 is a valid and reliable clinical instrument, demonstrating correlation with the psychophysical olfactory assessment.