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Review
. 2021 Jun 4;21(1):525.
doi: 10.1186/s12879-021-06214-4.

Coronavirus disease (COVID-19) pandemic: an overview of systematic reviews

Israel Júnior Borges do Nascimento  1   2 , Dónal P O'Mathúna  3   4 , Thilo Caspar von Groote  5 , Hebatullah Mohamed Abdulazeem  6 , Ishanka Weerasekara  7   8 , Ana Marusic  9 , Livia Puljak  10 , Vinicius Tassoni Civile  11 , Irena Zakarija-Grkovic  9 , Tina Poklepovic Pericic  9 , Alvaro Nagib Atallah  11 , Santino Filoso  12 , Nicola Luigi Bragazzi  13 , Milena Soriano Marcolino  1 ; International Network of Coronavirus Disease 2019 (InterNetCOVID-19)
Affiliations
Review

Coronavirus disease (COVID-19) pandemic: an overview of systematic reviews

Israel Júnior Borges do Nascimento et al. BMC Infect Dis. .

Abstract

Background: Navigating the rapidly growing body of scientific literature on the SARS-CoV-2 pandemic is challenging, and ongoing critical appraisal of this output is essential. We aimed to summarize and critically appraise systematic reviews of coronavirus disease (COVID-19) in humans that were available at the beginning of the pandemic.

Methods: Nine databases (Medline, EMBASE, Cochrane Library, CINAHL, Web of Sciences, PDQ-Evidence, WHO's Global Research, LILACS, and Epistemonikos) were searched from December 1, 2019, to March 24, 2020. Systematic reviews analyzing primary studies of COVID-19 were included. Two authors independently undertook screening, selection, extraction (data on clinical symptoms, prevalence, pharmacological and non-pharmacological interventions, diagnostic test assessment, laboratory, and radiological findings), and quality assessment (AMSTAR 2). A meta-analysis was performed of the prevalence of clinical outcomes.

Results: Eighteen systematic reviews were included; one was empty (did not identify any relevant study). Using AMSTAR 2, confidence in the results of all 18 reviews was rated as "critically low". Identified symptoms of COVID-19 were (range values of point estimates): fever (82-95%), cough with or without sputum (58-72%), dyspnea (26-59%), myalgia or muscle fatigue (29-51%), sore throat (10-13%), headache (8-12%) and gastrointestinal complaints (5-9%). Severe symptoms were more common in men. Elevated C-reactive protein and lactate dehydrogenase, and slightly elevated aspartate and alanine aminotransferase, were commonly described. Thrombocytopenia and elevated levels of procalcitonin and cardiac troponin I were associated with severe disease. A frequent finding on chest imaging was uni- or bilateral multilobar ground-glass opacity. A single review investigated the impact of medication (chloroquine) but found no verifiable clinical data. All-cause mortality ranged from 0.3 to 13.9%.

Conclusions: In this overview of systematic reviews, we analyzed evidence from the first 18 systematic reviews that were published after the emergence of COVID-19. However, confidence in the results of all reviews was "critically low". Thus, systematic reviews that were published early on in the pandemic were of questionable usefulness. Even during public health emergencies, studies and systematic reviews should adhere to established methodological standards.

Keywords: COVID-19; Coronavirus; Evidence-based medicine; Infectious diseases; SARS-Cov-2.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Fig. 1
Fig. 1
PRISMA flow diagram
Fig. 2
Fig. 2
A meta-analysis of the prevalence of mortality
Fig. 3
Fig. 3
A meta-analysis of the prevalence of fever
Fig. 4
Fig. 4
A meta-analysis of the prevalence of cough
Fig. 5
Fig. 5
A meta-analysis of the prevalence of dyspnea
Fig. 6
Fig. 6
A meta-analysis of the prevalence of fatigue or myalgia
Fig. 7
Fig. 7
A meta-analysis of the prevalence of headache
Fig. 8
Fig. 8
A meta-analysis of the prevalence of gastrointestinal disorders
Fig. 9
Fig. 9
A meta-analysis of the prevalence of sore throat
See this image and copyright information in PMC

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