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CompletedNCT04799977Updated Apr 22, 2025

COVID-19: Post-covid Olfactory Disorders Assessment

An observational study in Olfaction Disorders, sponsored by Centre Hospitalier Universitaire de Nice. Completed at 1 site in France. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-04-22.

Sponsored by Centre Hospitalier Universitaire de Nice · Observational

Study type
Observational
Model
Cohort
Time perspective
Retrospective
Enrollment
56
Ages
18 Years and older
Sex
All
01

Study summary

Covid 19 cause an olfactory loss in more than 80% of cases. This loss most often regresses but leaves 20% of patients with an olfactory complaint, particularly with regard to the quality of daily life. The neuro-cognitive implications involved with COVID19 and the consequences of persistent olfactory loss remain unknown. The effectiveness of therapeutic management, in particular olfactory re-education, has not yet been clarified. Objectives are the assessment of patients olfactory disorders, psychiatrics and neurocognitives specificities after a COVID, before and after treatment or specific cares.

02

Conditions studied

  • Olfaction Disorders

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03

In context

Olfaction Disorders

70 studies on the registry are indexed under Olfaction Disorders; 18 are open to participants now.

This study's enrollment of 56 is below the median of 81 across 16 observational studies indexed under Olfaction Disorders.

Browse Olfaction Disorders studies →

Lead sponsor

Centre Hospitalier Universitaire de Nice is the lead sponsor of 723 studies on the registry; 176 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No
Sampling method
Non-probability sample

Study population

All adult patients who presented with anosmia during their COVID19 infection (proven by a PCR+ test) and presenting at the ENT department consultation in university hospital more than 6 weeks after the end of symptoms,

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  • Adults patient,
  • anosmia during a COVID19 acute infection (PCR+) and persistant olfactive disoders at least 6 weeks after symptoms disappeared.

Exclusion criteria

Exclusion Criteria:

  • preexisting smell loss.
05

Study design

Observational model
Cohort
Time perspective
Retrospective
Enrollment
56 participants (actual)
Patient registry
No

Groups and cohorts

  • COVID19 infection with olfaction disorder

    Patients, ≥18 ans, who suffered from an olfaction disorder while going through a COVID19 infection

  • COVID19 infection without olfaction disorder

    Patients, ≥18 ans, who suffered from a COVID19 infection without any olfaction disorders

06

What researchers measure

Primary outcomes

  1. Sniffin Stick Tests (score TDI)

    The subjective olfactory losses and recoveries are most often evaluated using the "Sniffin 'Sticks Test®", the current gold standard of objective olfactory tests allowing in a single examination to group together: the definition of an olfactory threshold, olfactory discrimination and olfactory identification in the form of an overall TDI score. Olfactory function using psychophysical tests before and after treatment or specific cares : Sniffin Stick Tests (score TDI). Results can classified patients in Anosmic (TDI\<16,25), Hyposmic (16,25\<TDI\<30,75) and Normosmic (TDI\>30,75). Higher score = better results. Minimal clinically important difference = 5,5.

    Time frame: 12 months : Evalation at the beginning and the end.

Secondary outcomes

  1. Hamilton Depression Rating Scale (HDRS)

    The HDRS is used to assess the severity and progression of a patient's depressive state during a structured interview. This is a hetero-questionnaire consisting of 21 items completed in a few minutes by the examiner after an interview of at least 30 minutes. Before and after treatment or specific cares. Min-Max = 10-21. 10 \< score \< 13 = lights depression symptoms; 14\<score\<17 = mild deppression symptoms; \>18 = severe deppression symptoms ; Interrelationships assessment between psychophysical tests and theses results

    Time frame: 12 months : Evaluation at the beginning and the end.

  2. Situational anxiety and anxiety trait inventory (STAI-Y)

    The STAI is a self-administered questionnaire comprising 40 items. This scale consists of 2 parts: one evaluating the anxiety-state (AE) which reflects the current emotional state and the other evaluating trait anxiety (AT) which reflects the usual emotional state. Before and after treatment or specific cares. Each score can vary from 20 to 80 with a "very high" (\> 65), "high" (56-65), "average" (46-55), "low" (36-45) and "very low" (\<or = 35). Interrelationships assessment between psychophysical tests and theses results

    Time frame: 12 months : Evaluation at the beginning and the end.

  3. PTSD checklist for DSM-5 (PCL-5)

    The PCL-5 is a 20-item self-report that measures the 20 PTSD symptoms of DSM-5. The goals of PCL-5 are many, such as monitoring changes in symptoms during and after treatment, identifying individuals with PTSD, and making a provisional diagnosis of PTSD. Before and after treatment or specific cares. This self-rated scale scores each symptom from 0 to 4. Min-Max (better)=0-20. Interrelationships assessment between psychophysical tests and theses results.

    Time frame: 12 months : Evaluation at the beginning and the end.

  4. GREMOTS

    GREMOTS is a speech assessment test for neurological pathologies. This battery of tests takes into account the latest scientific development in the field and evaluates the different psycholinguistic variables of language. It also aims to detect disorders from the early stage of the disease. It componed of differents subtypes. We used the denomination and verification tasks. Semantic verification task: Min-Max=0-18. The cut-off score is between 5 and 25 percentil (inferior to 10-14). Denomination task: Min-Max=0-36. The cut-off score is between 5 and 25 percentil (inferior to 31-34).

    Time frame: 12 months : Evaluation at the beginning and the end.

  5. PPT

    The Pyramids and Palm Trees Test is a commonly used test of associative semanticknowledge comprising 52 items. In this test, participants are shown a stimulus (e.g., a pyramid) and asked to match it toeither of two images: A target (e.g., a palm tree) or a distracter (e.g., a fir tree). Subjects are required to use explicit semantic information of encyclopedic (e.g., pyramid: Palm tree vs. fir tree) or functional (e.g., wood: Saw vs. hammer) nature to select the correct match. Min-Max: 0-52. The 5% cut-off score corresponds to a Z-score of -1.65.

    Time frame: 12 months : Evaluation at the beginning and the end.

  6. GROBER BUSCHKE

    Grober and Buschke's is a commonly used test assesses verbal memory and is made up of 16 items belonging to 16 different semantic categories. The indexed reminder makes it possible to check the efficiency of the encoding and to dissociate memory disorders according to their type. Min-Max: 0-48. The cut-off score is inferior to 25 percentil.

    Time frame: 12 months : Evaluation at the beginning and the end.

  7. TAP (Test of Attentional Performance)

    The investigators used two tasks: the alertness task and the sustained attention task. In the alertness's task, reaction time is examined under two conditions. In the sustained attention task, a sequence of stimuli is presented on the monitor. The stimuli vary in a range of feature dimensions: colour, shape, size and filling. In order to adapt the difficulty of the task to the performance level of a subject, different levels of difficulty, that is, reactions to "shape" only or to "colour or shape", may be selected. Norms are betwaeen 19 and 89 for the alertness task and between 19 and 72 in sustained attention task.

    Time frame: 12 months : Evaluation at the beginning and the end.

  8. TODA2 Olfactive Identification

    The olfactory test was developed by the CoBTeK laboratory. It's an electronic test with mobile application which is componed of two tasks: a treshold task and an identification task. This task assess more precisely odor identification disorders by presenting semantic distractors at the higer treshold level. Min-Max treshold score: 1-4. Min-Max identification score: 0-24

    Time frame: 12 months : Evaluation at the beginning and the end.

  9. Snaith-HAmilton Pleasure Scale (SHAPS)

    The SHAPS is a 14-item self-administered questionnaire designed to assess a patient's hedonic capacity under different circumstances of daily life. Before and after treatment or specific cares. Min-Max = 0-14. Score \>3 Anhédonic symptom; Interrelationships assessment between psychophysical tests and theses results

    Time frame: 12 months : Evaluation at the beginning and the end.

  10. Inventory/Apathy Scale

    The principle of the Apathy Inventory (IA) is to obtain information on the presence of apathy in patients with neurological disorders. The investigators used the clinical version of the Apathy Inventory. It assess the 4 clinical dimensions: - Emotional blunting - Lack of initiative - Lack of interest- Social interactions. Score for each dimension: 0= no problem; 2= moderate problem; 4= major problem. Min-Max total score= 0-16..

    Time frame: 12 months : Evaluation at the beginning and the end.

  11. Olfactory Quality of life assessment - Short Version of questionnaire of olfactory disorders

    Specific quality of life related to olfaction disorders concerning Social, eating, anxiety and daily annoyance related behaviors. Min-Max = 0-21, the higher is the score, the better is olfactory quality of life

    Time frame: 12 months : Evaluation at the beginning and the end.

  12. General quality of life assessment (SF-36)

    General quality of life score. Two scores related to an aggregated physical score and a mental score. Normatives values are near 50 for both. Less than 45 is worst subdomain quality of life, better than 55 is better subdomain quality of life. MCID = 5

    Time frame: 12 months : Evaluation at the beginning and the end.

  13. The French quality of life and diet scale (QV-AF)

    The QV-AF is a scale developed and validated in French to assess the quality of life in adults and in particular the relationship to diet. 4 subscales: diet / pleasure dimension, diet / relationship dimension, diet / psychology dimension, diet and physical condition dimension. Before and after treatment or specific cares. Min-Max (better)=0-400. Interrelationships assessment between psychophysical tests and theses results.

    Time frame: 12 months : Evaluation at the beginning and the end.

07

Study locations

1 site
  • IUFC
    Nice, 06100, France
08

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reached

Ran from Oct 2020 to primary completion in Apr 2021, 6 months.

How these figures are worked out, and which studies are left out of them.

Registered
Feb 15, 2021
First posted
Mar 16, 2021
StartActual
Oct 1, 2020
Primary completionActual
Apr 1, 2021
CompletionActual
Apr 1, 2021
Last update
Apr 22, 2025
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Apr 22, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
09

Registry details

Key details

Study ID
NCT04799977
Responsible party
Sponsor
First posted
Mar 16, 2021
Start date
Oct 1, 2020
Primary completion
Apr 1, 2021
Completion
Apr 1, 2021
Last update
Apr 22, 2025

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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