Evaluation of the effect and factors related to olfactory rehabilitation in patients with olfactory dysfunction afterCOVID-19 infection

Evaluation of the effect of Olfactrain product in olfactory rehabilitation in patients with olfactory dysfunction after Covid-19 infection

A clinical trial with intervention and control groups, with parallel groups, double-blind, randomized, phase 2-3 on 240 patients. Blocks with size of four were used for randomization.

The location of the study is the Ear, Throat, and Nose Clinic of Amir Alam Hospital. This clinic is a reference center for studies and treatment of ear, throat, and nose diseases. Blinding was not done in this study. First, patients go to the established specialist and are visited. Then, for all patients, the demographic profile, satisfaction, and smell form are filled by the clinic personnel, then, if needed, a CT scan is performed in order to check their smell problem in detail. At the beginning of the treatment, a smell identification test is performed and their scores are recorded.

Inclusion criteria: Decreased olfactory or olfactory change after Covid-19 infection At least 3 months have passed since the onset of the olfactory disorder. - 18 - age of patients between 60 Exclusion criteria: - History of head trauma or olfactory loss before Covid-19 infection - History of illness, surgery, or brain tumor

Patients in the intervention group are treated for 3 months with olfactory rehabilitation with the four main scents of rose, eucalyptus, clove, and lemon. Patients in the control group are followed up for three months and after three months of waiting for olfactory rehabilitation.

Odor test score

The randomization type is blocked randomization. Bloke size 4 of intervention (A) and control (B) groups defined as (AABB, ABAB, ABBA, BBAA, BABA, BAAB) are written on six cards respectively on cards 1-6, then the cards in The envelope are placed. Each time, one of the cards is randomly taken out of the envelope and put together. Finally, a random string is made from the sequence of the selected cards (in the number of the sample size), respectively, patients A and B are entered into the study until the desired sample size is reached.