Pre-existing health conditions and severe COVID-19 outcomes: an umbrella review approach and meta-analysis of global evidence

Abstract

Background: This study applies an umbrella review approach to summarise the global evidence on the risk of severe COVID-19 outcomes in patients with pre-existing health conditions.

Methods: Systematic reviews (SRs) were identified in PubMed, Embase/Medline and seven pre-print servers until December 11, 2020. Due to the absence of age-adjusted risk effects stratified by geographical regions, a re-analysis of the evidence was conducted. Primary studies were extracted from SRs and evaluated for inclusion in the re-analysis. Studies were included if they reported risk estimates (odds ratio (OR), hazard ratio (HR), relative risk (RR)) for hospitalisation, intensive care unit admission, intubation or death. Estimated associations were extracted from the primary studies for reported pre-existing conditions. Meta-analyses were performed stratified for each outcome by regions of the World Health Organization. The evidence certainty was assessed using GRADE. Registration number CRD42020215846.

Results: In total, 160 primary studies from 120 SRs contributed 464 estimates for 42 pre-existing conditions. Most studies were conducted in North America, European, and Western Pacific regions. Evidence from Africa, South/Latin America, and the Eastern Mediterranean region was scarce. No evidence was available from the South-East Asia region. Diabetes (HR range 1.2-2.0 (CI range 1.1-2.8)), obesity (OR range 1.5-1.75 (CI range 1.1-2.3)), heart failure (HR range 1.3-3.3 (CI range 0.9-8.2)), COPD (HR range 1.12-2.2 (CI range 1.1-3.2)) and dementia (HR range 1.4-7.7 (CI range 1.2-39.6)) were associated with fatal COVID-19 in different regions, although the estimates varied. Evidence from Europe and North America showed that liver cirrhosis (OR range 3.2-5.9 (CI range 0.9-27.7)) and active cancer (OR range 1.6-4.7 (CI range 0.5-14.9)) were also associated with increased risk of death. Association between HIV and undesirable COVID-19 outcomes showed regional heterogeneity, with an increased risk of death in Africa (HR 1.7 (CI 1.3-2.2)). GRADE certainty was moderate to high for most associations.

Conclusion: Risk of undesirable COVID-19 health outcomes is consistently increased in certain patient subgroups across geographical regions, showing high variability in others. The results can be used to inform COVID-19 vaccine prioritisation or other intervention strategies.

Keywords: COVID-19; Comorbidities; Death; Hospitalisation; Pre-existing health conditions; SARS-CoV-2; Umbrella review.

Conflict of interest statement

Authors declare no conflicts competing interests.

© 2021. The Author(s).

Figures

Fig. 1

Results of the meta-analyses for pre-existing conditions: Liver and metabolic diseases (the upper panel) and respiratory diseases (the lower panel), by WHO region (excluding SEAR). The error bars represent 95% confidence intervals. The dashed line indicates 1.0 value. The estimates with error bars crossing the 1.0-line lack statistical significance

Fig. 2

Results of the meta-analyses for pre-existing conditions: Circulatory diseases (the upper panel) and overweight/obesity/underweight (the lower panel), by WHO region (excluding SEAR). The error bars represent 95% confidence intervals. The dashed line indicates 1.0 value. The estimates with error bars crossing the 1.0-line lack statistical significance

Fig. 3

Results of the meta-analyses for pre-existing conditions: Immunodeficiency (the upper panel), neurological diseases and mental health (the middle panel) and oncological diseases (lower panel), by WHO region (excluding SEAR). The error bars represent 95% confidence intervals. The dashed line indicates 1.0 value. The estimates with error bars crossing the 1.0-line lack statistical significance

Fig. 4

Summary of the GRADE assessment for each pre-existing condition, by health outcome and WHO region (red color - low,yellow color - moderate, green color - high). Outcomes include hospitalisation (HOSP), intensive care unit (ICU), in-hospital mortality (H.MOR), case mortality (C.MOR)

Fig. 5

Estimated associations supported by high certainty of evidence (GRADE) presented for each pre-existing condition and outcome for the European region and North America. The estimated associations are arranged by ascending value of measures of effect. However, the presented order should be considered in the context of differences between the statistics (OR, RR, HR)

Fig. 6

Estimated associations supported by high certainty of evidence (GRADE) presented for each pre-existing condition and outcome for the African, Eastern Mediterranean and Western Pacific regions. The estimated associations are arranged by ascending value of measures of effect. However, the presented order should be considered in the context of differences between the statistics (OR, RR, HR)

Fig. 7

Age-stratified estimates for pre-existing conditions extracted from the single studies. Due to differences in the age groups, the estimates were not pooled. Age groups are illustrated in each column as reported in the primary studies. Panel A illustrates single-study estimates for younger age groups. Panel B gives the estimates for older age groups. The error bars represent 95% confidence intervals. The dashed line indicates 1.0 value. The estimates with error bars crossing the 1.0-line lack statistical significance