Italian version of the Brief Questionnaire of Olfactory Disorders (Brief-IT-QOD)

Objective. To evaluate the reliability and validity of the Italian version of the Brief Questionnaire of Olfactory Disorders (Brief-IT-QOD). Methods. The study consisted of six phases: item generation, reliability analysis (112 dysosmic patients for internal consistency analysis and 61 for test-retest reliability analysis), normative data generation (303 normosmic subjects), validity analysis (comparison of Brief-IT-QOD scores of healthy and dysosmic subjects and scores correlation with psychophysical olfactory testing TDI and SNOT-22 scores), responsiveness analysis (10 dysosmic chronic rhinosinusitis with nasal polyps patients before and after biologic therapy), and cutoff value determination (ROC curve analysis of Brief-IT-QOD sensitivity and specificity). Results. All subjects completed the Brief-IT-QOD. Internal consistency (& alpha; > 0.70) and test-retest reliability (ICC > 0.7) were acceptable and satisfactory for both questionnaire subscales. A significant difference between dysosmic and control subjects was found in both subscales (p < 0.05). Significant correlations between subscales scores and TDI and SNOT-22 scores were observed. Brief-IT-QOD scores before treatment were significantly higher than after biological therapy. Conclusions. Brief-IT-QOD is reliable, valid, responsive to changes in QoL, and recommended for clinical practice and outcome research.