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KSR Number: KSRA129816

Prevalence and impact of cardiovascular metabolic diseases on COVID-19 in China

Risk of Bias Assessment

Overall summary: High risk of bias in the review

Bottom Line

There is some limited evidence to indicate that patients with pre-existing conditions (hypertension, cardiovascular and cerebrovascular disease, and diabetes) may be at increased risk of developing severe coronavirus disease 2019 (COVID-19), i.e. requiring intensive care admission. Conversely, severe COVID-19 may be associated with an increased risk of cardiac injury. This review provides an interesting initial exploration of the possible relationships between some co-morbidities and disease severity in COVID-19. However, the results should be interpreted cautiously, as the review has substantial methodological weaknesses.

Risk of Bias Assessment

Overall summary High risk of bias in the review


This review has substantial methodological weaknesses and has been rated high risk of bias on all domains.

A. Did the interpretation of findings address all of the concerns identified in Domains 1 to 4? No
B. Was the relevance of identified studies to the review's research question appropriately considered? Probably yes
C. Did the reviewers avoid emphasizing results on the basis of their statistical significance? Probably yes
Risk of bias in the review High

Details of Review

Number of studies 6
Number of participants 1527
Last search date February 2020
Review type Epidemiology
Objective To assess the prevalence and impact of cardiovascular metabolic diseases in 2019 novel coronavirus infection in China.
Population People with confirmed 2019 novel coronavirus infection, ICU and non-ICU cases (severe and non-severe if ICU data were not reported).
Interventions NA
Comparator NA
Outcome Comparative prevalence of comorbidities (hypertension, cardiovascular and cerebrovascular diseases and diabetes) and impact on cardiac injury in ICU and Non-ICU cases (or severe and non-severe cases, where ICU data were not provided).
Study design Unclear; the inclusion criteria specify comparative studies (randomised or non-randomised controlled trials), but the characteristics of the included studies do not include details of any intervention(s) or comparator(s).
Reference standard NA
Exposure NA
PP factor NA


The majority of the cases, in the six included studies, were localized in Wuhan, or linked to recent travel to Wuhan or contact to people from Wuhan. The median ages of study participants were, respectively, 56, 49, 47, 55.5, 34 and 57 years, with infection being diagnosed across the age spectrum, from newborn to 92 years. Across the included studies, the overall proportion of male participants was 57.8%.

Summary estimates (4 studies, n=1415 participants) indicated an overall prevalence of hypertension of 17.1% (95% confidence interval (CI) 9.9 to 24.4%), an overall prevalence of cardiovascular or cerebrovascular disease of 16.4% (95% CI 6.6 to 26.1%; 5 studies, n=1514 participants), and an overall prevalence of diabetes of 9.7% (95% CI 6.9 to 12.5%; 5 studies, n=1514 participants).

Where comparisons between intensive care unit (ICU)/severe and non-ICU/non-severe cases were possible, the summary estimates indicated that hypertension was present in 59/222 (28.8%) of ICU cases versus 138/1056 (14.1%) of non-ICU cases; relative risk (RR) 2.03, 95% CI 1.54 to 2.68; 3 studies, n=1278 participants). Similarly, cardiovascular or cerebrovascular disease was more common in ICU cases 37/222 (16.7%) than in non-ICU cases 54/1056 (6.2%); RR 3.30, 95% CI 2.03 to 5.36; 3 studies, n=1278 participants). The prevalence of diabetes appeared higher in ICU cases 37/222 (11.7%) than in non-ICU cases 68/1056 (4.0%); RR 2.21, 95% CI 0.88 to 5.57; 3 studies, n=1278 participants), however, the confidence interval includes the possibility of no difference.

Two studies (n=179 participants) reported data on cardiac injury (confirmed by elevated cardiac troponin T or I); the overall prevalence of cardiac injury, from these two studies, was 8% (95% CI 4.1 to 12.0%); the risk of cardiac injury was greater in ICU case than in non-ICU cases; RR 13.48 (95% CI 3.60 to 50.47).

Full Risk of Bias Assessment

The research objective was clearly stated and the inclusion criteria were generally appropriate; comparative studies (randomised or non-randomised controlled trials) were specified, but the characteristics of the included studies do not include details of any intervention(s) or comparator(s). Included studies were required to have >10 participants and to be published in English.

1.1 Did the review adhere to pre-defined objectives and eligibility criteria? Probably yes
1.2 Were the eligibility criteria appropriate for the review question? Probably yes
1.3 Were eligibility criteria unambiguous? Probably no
1.4 Were all restrictions in eligibility criteria based on study characteristics appropriate (e.g. date, sample size, study quality, outcomes measured)? Probably yes
1.5 Were any restrictions in eligibility criteria based on sources of information appropriate (e.g. publication status or format, language, availability of data)? No
Concerns regarding specification of study eligibility criteria High

PubMed and EMBASE were searched, from December 2019 to February 2020, for studies relating to 2019 novel coronavirus infection in China. Some search terms were reported but the search strategy was not provided. No information was provided about the number of reviewers involved in the study selection process.

2.1 Did the search include an appropriate range of databases/electronic sources for published and unpublished reports? Probably no
2.2 Were methods additional to database searching used to identify relevant reports? No
2.3 Were the terms and structure of the search strategy likely to retrieve as many eligible studies as possible? No information
2.4 Were restrictions based on date, publication format, or language appropriate? Probably yes
2.5 Were efforts made to minimise error in selection of studies? No information
Concerns regarding methods used to identify and/or select studies High

Only limited details of the included studies were reported (e.g. the study design(s) was not clear). No information about the number of reviewers involved in the data extraction process was provided. No assessment of the methodological quality of included studies was reported.

3.1 Were efforts made to minimise error in data collection? No information
3.2 Were sufficient study characteristics considered for both review authors and readers to be able to interpret the results? Probably no
3.3 Were all relevant study results collected for use in the synthesis? Probably yes
3.4 Was risk of bias (or methodological quality) formally assessed using appropriate criteria? Probably no
3.5 Were efforts made to minimise error in risk of bias assessment? Probably no
Concerns regarding methods used to collect data and appraise studies High

The summary estimates presented are of questionable value, given the small numbers of studies involved and substantial statistical heterogeneity in some instances.

4.1 Did the synthesis include all studies that it should? Probably yes
4.2 Were all pre-defined analyses reported or departures explained? Probably yes
4.3 Was the synthesis appropriate given the degree of similarity in the research questions, study designs and outcomes across included studies? Probably no
4.4 Was between-study variation minimal or addressed in the synthesis? Probably no
4.5 Were the findings robust, e.g. as demonstrated through funnel plot or sensitivity analyses? Probably no
4.6 Were biases in primary studies minimal or addressed in the synthesis? No
Concerns regarding synthesis and findings High


Background: Studies have reminded that cardiovascular metabolic comorbidities made patients more susceptible to suffer 2019 novel corona virus (2019-nCoV) disease (COVID-19), and exacerbated the infection. The aim of this analysis is to determine the association of cardiovascular metabolic diseases with the development of COVID-19. Method(s): A meta-analysis of eligible studies that summarized the prevalence of cardiovascular metabolic diseases in COVID-19 and compared the incidences of the comorbidities in ICU/severe and non-ICU/severe patients was performed. Embase and PubMed were searched for relevant studies. Result(s): A total of six studies with 1527 patients were included in this analysis. The proportions of hypertension, cardia-cerebrovascular disease and diabetes in patients with COVID-19 were 17.1%, 16.4% and 9.7%, respectively. The incidences of hypertension, cardia-cerebrovascular diseases and diabetes were about twofolds, threefolds and twofolds, respectively, higher in ICU/severe cases than in their non-ICU/severe counterparts. At least 8.0% patients with COVID-19 suffered the acute cardiac injury. The incidence of acute cardiac injury was about 13 folds higher in ICU/severe patients compared with the non-ICU/severe patients. Conclusion(s): Patients with previous cardiovascular metabolic diseases may face a greater risk of developing into the severe condition and the comorbidities can also greatly affect the prognosis of the COVID-19. On the other hand, COVID-19 can, in turn, aggravate the damage to the heart.Copyright © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.