Prognostic factors for mortality, ICU and hospital admission due to SARS-CoV-2: A systematic review and meta-analysis of cohort studies in Europe

  1. Constantine I. Vardavas
  2. Alexander G. Mathioudakis
  3. Katerina Nikitara
  4. Kimon Stamatelopoulos
  5. Georgios Georgiopoulos
  6. Revati Phalkey
  7. Jo Leonardi-Bee
  8. Esteve Fernandez
  9. Dolors Carnicer-Pont
  10. Jørgen Vestbo
  11. Jan C. Semenza
  12. Charlotte Deogan
  13. Jonathan E. Suk
  14. Piotr Kramarz
  15. Favelle Lamb
  16. Pasi Penttinen

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Abstract

Background

As mortality from COVID-19 is strongly age-dependent, we aimed to identify population subgroups at an elevated risk for adverse outcomes from COVID-19 using age/gender-adjusted data from European cohort studies with the aim to identify populations that could potentially benefit from booster vaccinations.

Methods

We performed a systematic literature review and meta-analysis to investigate the role of underlying medical conditions as prognostic factors for adverse outcomes due to SARS-CoV-2, including death, hospitalisation, Intensive Care Unit (ICU) admission, and mechanical ventilation within three separate settings (community, hospital and ICU). Cohort studies that reported at least age and gender-adjusted data from Europe were identified through a search of peer-reviewed articles published until 11 th June 2021 in Ovid Medline and Embase. Results are presented as Odds Ratios (ORs) with 95% confidence intervals (95%C.I.) and absolute risk differences (RD) in deaths per 1,000 COVID-19 patients.

Findings

We included 88 cohort studies with age/gender adjusted data from 6,653,207 SARS-CoV-2 patients from Europe. Hospital-based mortality was associated with high and moderate certainty evidence for solid organ tumours, diabetes mellitus, renal disease, arrhythmia, ischemic heart disease, liver disease, and obesity, while a higher risk, albeit with low certainty, was noted for chronic obstructive pulmonary disease and heart failure. Community-based mortality was associated with a history of heart failure, stroke, diabetes, and end-stage renal disease. Evidence of high/moderate certainty revealed a strong association between hospitalisation for COVID-19 and solid organ transplant recipients, sleep apnoea, diabetes, stroke, and liver disease.

Interpretation

The results confirmed the strong association between specific prognostic factors and mortality and hospital admission. Prioritisation of booster vaccinations and the implementation of non-pharmaceutical protective measures for these populations may contribute to a reduction in COVID-19 mortality, ICU and hospital admissions.

Funding

European Centre for Disease Prevention and Control (ECDC) under specific contract No. 10 ECD.11843 within Framework contract ECDC/2019/001 Lot 1B.

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  1. ScreenIT

    SciScore for 10.1101/2022.03.24.22272870: (What is this?)

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

    Table 1: Rigor

    Ethicsnot detected.
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    Relevant peer-reviewed studies published in English were identified within Medline (OVID) and EMBASE (OVID) until the 11th of June 2021.
    Medline
    suggested: (MEDLINE, RRID:SCR_002185)
    EMBASE
    suggested: (EMBASE, RRID:SCR_001650)

    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:
    Strengths and limitations: Several strengths of our meta-analysis increase our confidence in our findings. The inclusion of only age/gender adjusted cohort study data allowed us to control for the primary factor associated with adverse outcomes, which is the patient’s age, hence allowing us to assess the independent effect of each prognostic factor (106). Moreover, we performed separate analyses by clinical setting that allowed us to both quantify the incidence of adverse outcomes, as separate endpoints, which may assist in managing patient flows and triaging. As we applied the GRADE methodology for assessing the evidence about prognostic factors, we rigorously evaluated the certainty of the evidence behind each meta-analysis. Some limitations of our study should also be acknowledged as our results reflect the status quo in Europe during the first waves of the pandemic when the alpha and beta variants were most dominant and with the EU population largely unvaccinated, hence further research is needed to assess how subsequent vaccination would impact patient mortality. We restricted our inclusion criteria to Europe, to enhance the comparability of the results and utility for European clinicians and policymakers, as they have similar healthcare resources, acknowledging that our results may not be generalisable to other areas of the globe. However, similar results are noted in different geographical areas (107). Furthermore, there was evidence of heterogeneity as the definition ...

    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

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  2. Version published to 10.1101/2022.03.24.22272870v1 on medRxiv