Evaluating the Effect of Olfactory Training on Improving the Sense of Smell in Patients with COVID-19 with Olfactory Disorders: A Randomized Clinical Trial Study

Background The COVID-19 disease is associated with many complications, including the disorder of the sense of smell, which is stable even months after the infection and negatively impacts the patient’s quality of life. Nursing interventions to solve this problem are among the nursing care priorities for these patients. Therefore, this study aimed to determine the effect of olfactory training on improving the sense of smell in patients suffering from olfactory disorders with COVID-19. Methods This randomized clinical trial was based on pre-test-post-test type on people who were referred with a positive polymerase chain reaction (PCR) test in Babol, Iran, under the supervision of Babol city health center with the disorder in the sense of smell. A total of 100 patients were selected by the available method and randomly assigned to two intervention and control groups. Both groups completed the Questionnaire of Olfactory Disorders - Negative Statements (QOD-NS) before the intervention. The olfactory training intervention group was exposed to four categories of main scents: phenylethyl alcohol (the smell of roses from rose geranium), eucalyptus (the smell of eucalyptus), citronol (the smell of lemon), and eugenol (the smell of cloves) twice a day, morning, and night for six weeks, rotating for 20 seconds each with a ten-second interval between each scent. After completing the olfactory training course, both groups answered the quality of life questionnaire about smell. Finally, the data were analyzed using SPSS version 21, independent paired t-tests. Results The average score of olfactory disorder in patients with COVID-19 before the intervention in the intervention and control groups was 24.32 ± 6.60 and 22.85 ± 8.04, respectively, which did not have a significant difference (P = 0.33). The values reached 19.60 ± 5.74 and 22.52 ± 7.39, statistically significant (P = 0.034). Conclusion Olfactory training effectively improved the sense of smell in patients with COVID-19 suffering from olfactory disorders. Therefore, this program should be taught by nurses to improve patients with COVID-19 with olfactory disorders after discharge.