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Review
. 2022 May 10;11(5):563.
doi: 10.3390/pathogens11050563.

Heterogeneity and Risk of Bias in Studies Examining Risk Factors for Severe Illness and Death in COVID-19: A Systematic Review and Meta-Analysis

Abraham Degarege  1 , Zaeema Naveed  1 , Josiane Kabayundo  1 , David Brett-Major  1
Affiliations
Review

Heterogeneity and Risk of Bias in Studies Examining Risk Factors for Severe Illness and Death in COVID-19: A Systematic Review and Meta-Analysis

Abraham Degarege et al. Pathogens. .

Abstract

This systematic review and meta-analysis synthesized the evidence on the impacts of demographics and comorbidities on the clinical outcomes of COVID-19, as well as the sources of the heterogeneity and publication bias of the relevant studies. Two authors independently searched the literature from PubMed, Embase, Cochrane library, and CINAHL on 18 May 2021; removed duplicates; screened the titles, abstracts, and full texts by using criteria; and extracted data from the eligible articles. The variations among the studies were examined by using Cochrane, Q.; I2, and meta-regression. Out of 11,975 articles that were obtained from the databases and screened, 559 studies were abstracted, and then, where appropriate, were analyzed by meta-analysis (n = 542). COVID-19-related severe illness, admission to the ICU, and death were significantly correlated with comorbidities, male sex, and an age older than 60 or 65 years, although high heterogeneity was present in the pooled estimates. The study design, the study country, the sample size, and the year of publication contributed to this. There was publication bias among the studies that compared the odds of COVID-19-related deaths, severe illness, and admission to the ICU on the basis of the comorbidity status. While an older age and chronic diseases were shown to increase the risk of developing severe illness, admission to the ICU, and death among the COVID-19 patients in our analysis, a marked heterogeneity was present when linking the specific risks with the outcomes.

Keywords: COVID-19; comorbidities; death; demographics; severe illness.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
PRISMA flow diagram. Numbers of articles retrieved from databases, screened, excluded, and included.
Figure 2
Figure 2
Forest plot showing the relationship of hypertension with the odds of admission to the ICU among COVID-19 patients.
Figure 3
Figure 3
Forest plot showing the relationship of cardiovascular disease with the odds of admission to the ICU among COVID-19 patients.
Figure 4
Figure 4
Forest plot showing the relationship of diabetes with the odds of admission to the ICU among COVID-19 patients.
Figure 5
Figure 5
Forest plot showing the relationship of chronic respiratory diseases with the odds of severe illness among COVID-19 patients.
Figure 6
Figure 6
Forest plot showing the relationship of chronic respiratory diseases with the odds of admission to the ICU among COVID-19 patients.
Figure 7
Figure 7
Forest plot showing the relationship between chronic liver disease and the odds of death, severe illness, and admission to the ICU among COVID-19 patients.
Figure 8
Figure 8
Forest plot showing the relationship of cerebrovascular diseases with the odds of death, severe illness, and admission to the ICU among COVID-19 patients.
Figure 9
Figure 9
Forest plot showing the relationship of smoking with the odds of severe illness and admission to the ICU among COVID-19 patients.
See this image and copyright information in PMC

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