Clinical laboratory characteristics of severe patients with coronavirus disease 2019 (COVID-19): A systematic review and meta-analysis

Objectives: To identify clinical characteristics of severe patients with COVID-19. Methods: The WHO database of publications on COVID-19 and PubMed were searched from inception to March 20, 2020 and all valuable studies were analyzed using Stata 15.0. Results: We selected forty-four studies with 13,497 patients. In the comparison of severe and non-severe groups, age over 50 (OR = 4.090; 95% CI = 2.422-6.907, P = 0.000) and underlying disease (OR = 3.992; 95% CI = 2.631-6.507, P = 0.000) are risk factors. Female gender (OR = 0.740; 95% CI = 0.622-0.881, P = 0.001) is a protective factor. Characteristics like dyspnea (OR = 4.914; 95% CI = 3.069-7.867, P = 0.000), lymphopenia (OR = 5.528; 95% CI = 3.484-8.772, P = 0.000), thrombocytopenia (OR = 3.623; 95% CI = 1.034-12.691, P = 0.044), elevated C-reactive protein (OR = 5.217; 95% CI = 2.459-11.070, P = 0.000) and D-dimer (OR = 3.780; 95% CI = 1.481-9.648, P = 0.005) were more frequently in severe cases. Diffuse lesions and consolidation (OR = 4.680; 95% CI = 3.183-6.881, P = 0.000) in imaging was considered reliable. Conclusions: Men older than 50 with underlying disease are susceptible to develop severe pneumonia while female gender is protective. The typical symptom of severe pneumonia was dyspnea, but high fever, headache and diarrhea were not significantly different among patients with varying degrees of severity. Lymphopenia, thrombocytopenia, elevated C-reactive protein and D-dimer occurred more frequently in severe patients and yet leukopenia is not a characteristic laboratory indicator. Diffuse lesions and consolidation are important imaging features to distinguish severe pneumonia.

Automated summary

Men over 50 with underlying diseases are more susceptible to severe pneumonia, while females are less likely to develop severe symptoms. Critical patients are more likely to experience symptoms like dyspnea, lymphopenia, thrombocytopenia, elevated C-reactive protein, and D-dimer. Diffuse lesions and consolidation in imaging are crucial for identifying severe pneumonia.