Test-retest assessment of the olfactory test reliability (Odorized Markers Test)

Abstract

Aim: The aim of this study was to determine the test-retest reliability of the Odorized Markers Test (OMT). This psychophysical test is a tool for screening anosmia based on the identification of odorants. The test is used for the Czech population. Examination technique consists of two parts. First, subjects are asked to spontaneously name the odorants and second, subjects have to choose the most proper name for an odorant from four descriptors. Methods: The participants included 150 subjects: 77 healthy subjects and 73 patients with smell disorders. Olfactory functions were assessed using the OMT. Retest was performed on an average interval of 2 days. Results: The coefficient of correlation between the first test and retest was 0.91. The test-retest showed that the controls reached higher scores than patients with olfactory impairment (P < 0.001). The first part of the test showed higher degree of internal consistency than the second part. The results for the first testing were alpha = 0.9 and 0.56, respectively, and for retesting alpha = 0.89 and 0.65, respectively. Anosmia was found in 26 (17%) and 27 (18%) patients on test and retest, respectively. Conclusion: Positive significant correlation was found between the first test and retest. Internal consistency was satisfactory in both the first test and retest. Based on the results of our study, OMT is a reliable and valid test for olfactory evaluation in clinical practice.