Severity of Respiratory Infections due to SARS-CoV-2 in Working Population: Age and Body Mass Index Outweigh ABO Blood Group

  1. Johannes Schetelig
  2. Henning Baldauf
  3. Sarah Wendler
  4. Falk Heidenreich
  5. Ruben Real
  6. Martin Kolditz
  7. Andrea Rosner
  8. Alexander Dalpke
  9. Katja de With
  10. Vinzenz Lange
  11. Jan Markert
  12. Ralf Barth
  13. Carolin Bunzel
  14. Dennis Endert
  15. Jan A Hofmann
  16. Jürgen Sauter
  17. Stefanie N Bernas
  18. Alexander H Schmidt

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Abstract

Background

With increasing rates of SARS-CoV-2 infections and the intention to avoid a lock-down, the risks for the working population are of great interest. No large studies have been conducted which allow risk assessment for this population.

Methods

DKMS is a non-profit donor center for stem cell donation and reaches out to registered volunteers between 18 and 61 years of age. To identify risk factors for severe COVID-19 courses in this population we performed a cross-sectional study. Self-reported data on oro- or nasopharyngeal swabs, risk factors, symptoms and treatment were collected with a health questionnaire and linked to existing genetic data. We fitted multivariable logistic regression models for the risk of contracting SARS-CoV-2, risk of severe respiratory infection and risk of hospitalization.

Findings

Of 4,440,895 contacted volunteers 924,660 (20.8%) participated in the study. Among 157,544 participants tested, 7,948 reported SARS-CoV-2 detection. Of those, 947 participants (11.9%) reported an asymptomatic course, 5,014 (63.1%) mild/moderate respiratory infections, and 1,987 (25%) severe respiratory tract infections. In total, 286 participants (3.6%) were hospitalized for respiratory tract infections. The risk of hospitalization in comparison to a 20-year old person of normal weight was 2.1-fold higher (95%-CI, 1.2-3.69, p=0.01) for a person of same age with a BMI between 35-40 kg/m 2 , it was 5.33-fold higher (95%-CI, 2.92-9.70, p<0.001) for a 55-year old person with normal weight and 11.2-fold higher (95%-CI, 10.1-14.6, p<0.001) for a 55-year old person with a BMI between 35-40 kg/m 2 . Blood group A was associated with a 1.15-fold higher risk for contracting SARS-CoV-2 (95%-CI 1.08-1.22, p<0.001) than blood group O but did not impact COVID-19 severity.

Interpretation

In this relatively healthy population, the risk for hospitalizations due to SARS-CoV-2 infections was moderate. Age and BMI were major risk factors. These data may help to tailor risk-stratified preventive measures.

Funding

DKMS initiated and conducted this study. The Federal Ministry of Education and Research (BMBF) supported the study by a research grant (COVID-19 call (202), reference number 01KI20177).

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  1. Version published to 10.1101/2020.11.05.20226100v2 on medRxiv
  2. ScreenIT

    SciScore for 10.1101/2020.11.05.20226100: (What is this?)

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

    Table 1: Rigor

    Institutional Review Board StatementIRB: The responsible Institutional Review Board of the Technische Universität Dresden (IRB00001473) approved the study.
    Consent: All participants provided explicit consent that COVID-19 specific data were linked to immunogenetic data in the DKMS donor registry file.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.

    Table 2: Resources

    No key resources detected.

    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:
    Our study has several limitations: First, we analyzed self-reported data. Test results from oro- or nasopharyngeal swabs were not verified. Further, gender-specific or smoker-specific behavior in response to the pandemic may have biased our data 30. Second, the phenotype definitions based on self-reported symptoms without objective measurements. Therefore, we introduced respiratory hospitalization as a more stringent – but non-standard - definition for severity in order to exclude hospitalizations for isolation or social indications. Third, negative cases had no confirmed COVID-19 infection during the past 6 months. However, this did not preclude asymptomatic or mild to moderate SARS-CoV-2 infections, which had not been diagnosed. Forth, rates of positive tests must not be interpreted as incidences because our study population is not a random sample of the general population. Fifth, by design, we could not collect data on events, which incapacitated volunteers to respond. The infection-fatality-rate of adults below 61 years of age is low, but the rate of respiratory hospitalization calculated from self-reported data systematically underestimates the true rate of hospitalizations by this margin. Taken together, the data show a moderate risk of respiratory hospitalizations due to SARS-CoV-2 infection in this cohort of mostly healthy participants ranging between 18 and 61 years of age. The risk for hospitalization, however, varied substantially depending on age and BMI. Blood gr...

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We found bar graphs of continuous data. We recommend replacing bar graphs with more informative graphics, as many different datasets can lead to the same bar graph. The actual data may suggest different conclusions from the summary statistics. For more information, please see Weissgerber et al (2015).

    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.
    • Thank you for including a protocol registration statement.

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  3. Version published to 10.1101/2020.11.05.20226100v1 on medRxiv