Reliability and validity of the Chinese version of the questionnaire of olfactory disorders (QOD) when used with patients having olfactory dysfunction

To cross-culturally adapt the Questionnaire of olfactory disorders (QOD) into a Chinese version, and then evaluate its reliability and validity for testing patients with olfactory dysfunction. A Chinese version of the QOD was evaluated for test-retest reliability, split-half reliability, and internal consistency. The validity analysis included components of content validity and criterion-related validity, as well as comparisons between The Medical Outcomes Study's36-Item ShortForm Health Survey(SF-36)questionnaire and the WHO Quality of Life-BREF (WHOQOL-BREF)questionnaire. A total of 125 patients with olfactory dysfunction were tested, and 104 patients completed three different surveys (QOD, SF-36, and WHOQOL-BREF). The test-retest reliabilities of the QOD-Parosmia statements (QOD-P), QOD-Quality of life (QOD-QoL), and QOD-Visual simulation (QOD-VAS)sections were 0.802 (P < 0.001), 0.797 (P < 0.001), and 0.468 (P < 0.001), respectively, and the Cronbach's α coefficients of internal consistency were 0.473, 0.814, and 0.882, respectively. The split-half reliability was 0.70. No correlation was found between the QOD-P section and the SF-36; however, there were statistically significant correlations between the QOD-QoL andQOD-VAS sections and the SF-36. The same results were observed for correlations between the QOD and WHOQOL-BREF. The Chinese version of the QOD was proven to be a generally reliable and valid questionnaire for use in evaluating mainland Chinese patients suspected of having olfactory dysfunction. However, the QOD-P section requires further modifications to properly evaluate patients with a Chinese cultural background and type of cognition.