Persisting chemosensory impairments in 366 healthcare workers following COVID-19: an 11-month follow-up

  1. Nicholas Bussiere
  2. Jie Mei
  3. Cindy Levesque-Boissonneault
  4. Mathieu Blais
  5. Sara Carazo
  6. Francois Gros-Louis
  7. Robert Laforce
  8. Gaston De Serres
  9. Nicolas Dupre
  10. Johannes Frasnelli

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Abstract

Olfactory and gustatory dysfunctions (OD, GD) are prevalent symptoms following COVID-19 and persist in 6%–44% of individuals post-infection. As only few reports have described their prognosis after 6 months, our main objective was to assess the prevalence of OD and GD 11-month post-COVID-19. We also aimed to determine intraclass correlation coefficients (ICC) of chemosensory self-ratings for the follow-up of chemosensory sensitivity. We designed an observational study and distributed an online questionnaire assessing chemosensory function to healthcare workers with a RT-PCR-confirmed SARS-CoV-2 infection 5- and 11-month post-COVID-19. Specifically, we assessed olfaction, gustation, and trigeminal sensitivity (10-point visual analog scale) and function (4-point Likert scale). We further measured clinically relevant OD using the Chemosensory Perception Test, a psychophysical test designed to provide a reliable remote olfactory evaluation. We included a total of 366 participants (mean [SD] age of 44.8 (11.7) years old). They completed the last online questionnaire 10.6 months (0.7) after the onset of COVID-19 symptoms. Of all participants, 307 (83.9%) and 301 (82.2%) individuals retrospectively reported lower olfactory or gustatory sensitivity during the acute phase of COVID-19. At the time of evaluation, 184 (50.3%) and 163 (44.5%) indicated reduced chemosensory sensitivity, 32.2% reported impairment of olfactory function while 24.9% exhibited clinically relevant OD. Olfactory sensitivity had a high test–retest reliability (ICC: 0.818; 95% CI: 0.760–0.860). This study suggests that chemosensory dysfunctions persist in a third of COVID-19 patients 11 months after COVID-19. OD appears to be a common symptom of post-COVID-19 important to consider when treating patients.

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  1. ScreenIT

    SciScore for 10.1101/2021.12.20.21268066: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    EthicsIRB: Standard protocol approvals, registrations, and patient consents: This study was reviewed and approved by the research ethics board of the CHU de Québec – Université Laval (MP-20-2021-5228) and all protocols were reviewed by an independent Scientific Review Committee.
    Consent: All participants provided an online informed consent prior to participation.
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    Participants: Healthcare workers with a positive SARS-CoV-2 PCR test were recruited among those who had completed the initial online questionnaire at 5 months after onset of symptoms.
    Participants: Healthcare
    suggested: None
    Statistical Analysis: A custom Python script (Python 3.7.5
    Python
    suggested: (IPython, RRID:SCR_001658)
    , Python Software Foundation, https://www.python.org) and SPSS 26.0 (Armonk,
    https://www.python.org
    suggested: (CVXOPT - Python Software for Convex Optimization, RRID:SCR_002918)
    SPSS
    suggested: (SPSS, RRID:SCR_002865)
    Processed data were analyzed and visualized with SPSS 26.0, GraphPad Prism 8.3.1 (GraphPad Prism Software, San Diego, CA) and Raincloud plots 23.
    GraphPad Prism
    suggested: (GraphPad Prism, RRID:SCR_002798)
    GraphPad
    suggested: (GraphPad Prism, RRID:SCR_002798)

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    Limitations: A major limitation of this study was the absence of a commonly used psychophysical test to assess the extent of chemosensory dysfunction. Therefore, our results obtained with the CPT were more difficult to compare directly with other studies using psychophysical testing. Unfortunately, in clinical practice, psychophysical evaluations are seldom used for the diagnosis and follow-up of chemosensory impairments, which are mostly treated based on subjective assessments. While we encourage the use of validated psychophysical tests in primary care, neurology and ENT clinics, findings in this study confirmed a reliability of questioning olfactory functions subjectively especially in the context of follow-up of COVID-19 patients. An additional limitation of this study was the high prevalence of chemosensory disorders during the acute phase of COVID-19. Indeed, we observed higher participation rates among individuals with chemosensory disorders than those who have either recovered or simply never noticed any OD, GD or TD. Our study sample had a 20% higher rate of OD and GD, thus probably over estimating prevalence of chemosensory disorders at 11 months.

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    Results from scite Reference Check: We found no unreliable references.

    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.

  2. Version published to 10.1093/chemse/bjac010
  3. Version published to 10.1101/2021.12.20.21268066v1 on medRxiv