The Effect of Olfactory Training in Patients With COVID-19 Induced Olfactory Dysfunction - A Randomized Placebo-controlled Clinical Trial
| Registry | NCT05539560, acronym SMELLT2022 |
|---|---|
| Status | Unknown |
| Phase | Not applicable |
| Study type | Interventional; randomized, parallel, masking: quadruple, treatment |
| Enrollment | 65 (Estimated) |
| Sponsor | Ditte Gertz Mogensen (Other) |
| Conditions | COVID-19 |
| Interventions | Olfactory training with essential oils, Olfactory training with fragrance-free oils (Other) |
| Dates | start 2022-06-29, primary completion 2024-04-30, completion 2025-09-30 (estimated), first posted 2022-09-14, last updated 2024-09-23 |
| Locations | 1 site in Denmark |
Related Papers Related Patents Related Grants Related Experts
All trials for COVID-19 All trials of Olfactory training with essential oils All trials of Olfactory training with fragrance-free oils
Aim: The aim is to investigate the effect of olfactory training with essential oils versus olfactory training with placebo-oils in patients with COVID-19 induced olfactory dysfunction
Study design: The study is a placebo-controlled randomized clinical trial with an intervention group and a control group. The intervention group receive four essential oils with scents of orange, lavender, clove, and peppermint. Patients in the control group receive a fragrance kit, consisting of the same containers, but with fragrance-free oils added. Both groups are instructed to smell each of the four oils for 30 seconds in the morning and evening, over a three-month intervention period. Patients are given a diary in which to record their olfactory training. The nurse or medical student instructing the patients in the training and performing the smell and taste tests is blinded.
Study population: Patients referred to the Unit for Sense of Taste and Smell in the Department of Otorhinolaryngology Head \& Neck and Audiology at Rigshospitalet.
Inclusion criteria:
* Impaired sense of taste and smell following COVID-19 > 3 months
* Hyposmia (16.25-30.5) or anosmia (<16) assessed by Sniffin' Sticks Olfactory Test for Threshold, Discrimination and Identification (TDI) performed in the Unit for Sense of Taste and Smell with or without parosmia based on medical history
* > 18 years of age
Exclusion criteria:
* Cause of hyposmia, anosmia or parosmia other than COVID-19
* Does not read or speak Danish
* Lack of compliance to perform daily olfactory training
Procedures:
\- TDI-test: To assess patients' sense of smell, the TDI-test with Sniffin' Sticks is used, which is a validated tool with normative data.
Questionnaires:
\- 'Taste and Smell Tool for Evaluation' is used to investigate quality of life related to impaired sense of taste and smell.
| Arm | Type | Interventions | Description |
|---|---|---|---|
| Intervention group | Experimental | Other: Olfactory training with essential oils | Olfactory training twice a day with essential oils |
| Control group | Placebo comparator | Other: Olfactory training with fragrance-free oils | Olfactory training twice a day with fragrance-free oils |
Sex: All, ages: 18 Years to any
Inclusion Criteria: * Olfactory dysfunction caused by COVID-19 * Hyposmia (16.25-30.5) or anosmia (<16) with or without parosmia assessed by TDI test with Sniffin Sticks performed in the Unit for Sense of Taste and Smell * > 18 years of age Exclusion Criteria: * Cause of hyposmia, anosmia or parosmia other than COVID-19 * Does not read or speak Danish * Lack of compliance to perform daily olfactory training
| Facility | City | Country | Status |
|---|---|---|---|
| Department of Otorhinolaryngology, Head and Neck Surgery & Audiology, Copenhagen University Hospital | Copenhagen | Denmark | Recruiting |