Olfaction-associated quality of life: Polish adaptation and validation of a Questionnaire of Olfactory Disorders (QOD-PL) in patients with chronic rhinosinusitis

Background. The focus on health-related quality of life (HRQOL) in medical research is becoming more and more intensive, with attention being paid to the patient's subjective feelings and assessment of one's health status. Smell disorders can significantly impact human life. The Questionnaire of Olfactory Disorders (QOD) is a self-monitoring questionnaire that provides subjective information about olfactory disorders.Objectives. This study aimed to check the reliability and validation of the Polish version of QOD (QOD-PL) for use in patients with olfactory impairment in Poland.Materials and methods. A total of 158 patients (76 females, mean age (Mage) 45.97 +/- 16.37 years), suffering from chronic rhinosinusitis (CRS), whose olfactory function was measured using the Sniffin' Sticks test (SST), were studied. All patients completed 3 validated questionnaires: Importance of Olfaction (IO), Sino-Nasal Outcome Test-22 (SNOT-22) and QOD-PL. Results. Internal consistency and test-retest reliability of the entire QOD-PL scale were good (Cronbach's alpha = 0.88). The convergent validity of the QOD-PL and its subscales correlated with IO and SNOT-22. The life quality statements in the QOD-PL (QOD-PL-LQ) score, its negative statements, and the mean score for VAS scales were significantly and positively correlated with all symptoms measured with SNOT-22 and none of the IO scales.Conclusions. The QOD-PL is a reliable, valid and important tool for assessing HRQOL in patients with olfactory disorders. However, it is important to note that not all of its subscales can be considered and interpreted separately.