The prevalence of olfactory dysfunction and its associated factors in patients with COVID-19 infection

  1. Md Mehedi Hasan
  2. Naima Ahmed Tamanna
  3. Mohammad Nasimul Jamal
  4. Md Jamal Uddin

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Abstract

Objective

To determine the prevalence of olfactory dysfunctions, mainly, anosmia and to identify its associated factors in patients with COVID-19 infection.

Study design

A hospital-based prospective observational cohort study

Setting

A COVID dedicated hospital, Square Hospitals Ltd., Dhaka, Bangladesh.

Methods

We collected patients’ information including laboratory-confirmed COVID-19 test results. We used Pearson Chi-square test and logistic regression model to assess the associations between demographic and clinical characteristics and olfactory outcomes.

Results

Out of 600 COVID-19 positive patients, 38.7% were diagnosed with olfactory dysfunction. Our analyses showed that patients’ age, smoking status, cough, dyspnea, sore throat, asthenia, and nausea or vomiting were significantly associated with the anosmia. We observed the risk of developing anosmia was greater in younger patients than in older patients, and this risk decreased as age increased [odds ratio (OR) range for different age groups: 1.26 to 1.08]. Smoking patients were 1.73 times more likely to experience anosmia than non-smoking patients [OR=1.73, 95% confidence interval (CI) = 1.01-2.98]. In addition, patients complained asthenia had a significantly double risk of developing the anosmia [OR = 1.96, CI = 1.23-3.06].

Conclusions

Our study shows that about 39% of patients diagnosed with olfactory dysfunction. Patients’ age, smoking status, and asthenia are significantly positively associated with the anosmia. Since anosmia can be a significant marker for the diagnosis of COVID-19, we suggest regular screening of olfactory dysfunction in patients with early symptoms of COVID-19, particularly younger patients, smoker, and complained asthenia.

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  1. ScreenIT

    SciScore for 10.1101/2021.01.27.21250153: (What is this?)

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

    Table 1: Rigor

    Institutional Review Board StatementConsent: Ethical statement and inform consent: Informed consent was taken from the patient or legal guardian of the patient.
    IRB: Ethics committee approval: The ethical clearance was taken from the ethical committee at SQUARE Hospital Ltd.
    IACUC: Ethics committee approval: The ethical clearance was taken from the ethical committee at SQUARE Hospital Ltd.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variableThe inclusion criteria were: laboratory-confirmed COVID-19 infection (reverse transcription-polymerase chain reaction, RT-PCR); adult (> 18 years old); both male and female; and patients clinically stable to answer the questionnaire.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    Statistical Package for the Social Sciences for Windows (SPSS version 25) was used to perform the statistical analyses.
    Statistical Package for the Social Sciences
    suggested: (SPSS, RRID:SCR_002865)
    SPSS
    suggested: (SPSS, RRID:SCR_002865)

    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:
    The total population were tested COVID-19 positive and data were taken from them directly which are true strength for our study whereas it has several limitations as well including small sample size. Due to the increased risk of contamination among staffs, we avoid direct smell identification tests and the clinical data were collected with the help of the questionnaire. As the study is hospital-based study, maximum patients were elderly and hospitalized.

    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.

    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 10.1101/2021.01.27.21250153v1 on medRxiv