Validity and Reliability of a French Version of the Empty Nose Syndrome 6-Item Questionnaire

<b>Objective</b>: To validate a French version of the Empty Nose Syndrome 6-Item Questionnaire (Fr-ENS6Q). <b>Methods</b>: Thirty-three patients with a diagnosis of empty nose syndrome (ENS) and 50 healthy individuals completed the Fr-ENS6Q and the French versions of the Sinonasal Outcome Tool-22 (Fr-SNOT22) and Nasal Obstruction Symptom Evaluation (Fr-NOSE). The internal consistency (Cronbach-α), test-retest reliability (intraclass correlation coefficient (ICC)), and external validity (correlations between Fr-ENS6Q, Fr-SNOT-22, and Fr-NOSE) were evaluated. The threshold of Fr-ENS6Q for suspecting ENS diagnosis was calculated using the receiver operating characteristic (ROC) curve. Depression and anxiety were investigated with the General Anxiety Disorder-7 (GAD-7) and the Patient Health Questionnaire-9 (PHQ-9). <b>Results</b>: The Cronbach-α of Fr-ENS6Q was 0.81, indicating an adequate internal consistency. Patients reported higher ENS6Q scores than controls, indicating high internal validity. The Fr-ENS6Q was significantly correlated with the Fr-NOSE (r_s = 0.56; <i>p</i> = 0.001) and Fr-SNOT22 (r_s = 0.67; <i>p</i> = 0.001), which supports a high external validity. The test-retest reliability was high for ENS6Q scores (ICC = 0.895; 95%CI: 0.763-0.971). An ENS diagnosis can be suspected with an Fr-ENS6Q cutoff ≥ 12 for French-speaking ENS patients. Depression was detected in 97% of patients, with 84.9% requiring further assessment. Patients reported missing symptoms in the ENS6Q, such as sleep disturbance related to nasal airflow disorder, face/eye/dental pain, and fresh nasal sensations during airflow. <b>Conclusions</b>: The Fr-ENS6Q is a valid and reliable patient-reported outcome questionnaire for assessing the severity of ENS symptoms in the French-speaking population. Further improvements to the ENS6Q could consider the inclusion of symptoms that are not present in the current ENS6Q.