The male excess case-fatality rates for COVID-19 – A meta-analytic study of the age-related differences and consistency over six countries

  1. Manfred S Green
  2. Naama Schwartz
  3. Dorit Nitzan
  4. Victoria Peer

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Abstract

Background

Early in the COVID-19 pandemic, it was noted that males seemed to be more affected than females. We examined the magnitude and consistency of the sex differences in age-specific case-fatality rates (CFRs) in six countries.

Methods

Data on the cases and deaths from COVID-19, by sex and age group, were extracted from the published reports from Denmark, England, Israel, Italy, Spain, and the United States. Age-specific CFRs were computed for males and females separately. The ratio of the male to female CFRs were computed and meta-analytic methods were used to obtained pooled estimates of the male to female ratio of the CFRs over the six countries, for seven age-groups.

Findings

The CFRs were consistently higher in males at all ages. The differences were greater in the younger age groups. The pooled M:F CFR ratios were 2.53, 2.92, 2.57, 1.83, 1.57, 1.58 and 1.48 for ages 0-39, 40-49, 50-59, 60-69, 70-79, 80-89 and 90+. There was remarkable consistency between countries in the magnitude of the M:F CFRs, in each age group. In meta-regression, age group explained almost all the heterogeneity in the CFR ratios.

Conclusions

The sex differences in the CFRs are intriguing and are compatible with the male dominance in the incidence rates of many infectious diseases. For COVID-19, factors such as sex differences in the prevalence of underlying diseases may play a part in the CFR differences. However, the greater severity of the disease in males, particularly at younger ages, may be part of the disease mechanism and should be explored further.

Funding

No funding was provided for this study. The authors declare no conflict of interests

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  1. Version published to 10.1101/2020.06.11.20128439v2 on medRxiv
  2. ScreenIT

    SciScore for 10.1101/2020.06.11.20128439: (What is this?)

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

    Table 1: Rigor

    Institutional Review Board StatementIRB: Ethics: National, open access aggregative and anonymous data were used and there was no need for ethics committee approval.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variableThe ratio of the male to female CFRs (CFRR) was calculated by dividing the CFRs for males by the CFRs for females, by age group and country.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    Heterogeneity was evaluated using Cochran’s Q statistic.
    Cochran’s
    suggested: None
    The meta-analyses and meta-regressions were carried out using STATA software version 12.1 (Stata Corp., College Station, TX).
    STATA
    suggested: (Stata, RRID:SCR_012763)

    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: An explicit section about the limitations of the techniques employed in this study was not found. We encourage authors to address study limitations.

    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

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  3. Version published to 10.1101/2020.06.11.20128439v1 on medRxiv