Participants
The association between presence of distorted olfactory perception and improvement of olfactory performance after OT was analysed in 246 subjects (106 men, 140 women, mean (±SD) age 58.7 ± 7.3 years). Diagnosis included 153 postinfectious-, 31 posttraumatic-, and 62 idiopathic- related OD (Table 1 ). Olfactory training was performed for a mean (±SD) period of 25.8±8 weeks. Although 292 participants were initially included in the study, the analysis was performed on the basis of ‘listwise’ exclusion in case of missing values, resulting in a total of 46 subjects being excluded from the final analysis sample (n = 246).