Highlights • Fever was associated with poor outcomes in patients with COVID-19. • Leukocytosis was associated with severe disease. • Leukopenia was associated with a better prognosis. • CRP was associated with poor prognosis. • Leuocytosis and CRP on arrival may predict severe COVID-19. Background Since December 2019, coronavirus 2019 (COVID-19) has spread worldwide. Identifying poor prognostic factors is helpful for risk stratification. In this meta-analysis, we investigated the association between severe COVID-19 and a change in white blood cell (WBC) count, an elevation of C-reactive protein (CRP), and fever. Moreover, we aimed to evaluate the diagnostic accuracy of leukocytosis and an elevation of CRP. Methods We performed a systematic search of PubMed, EMBASE, Scopus, and the Cochrane Library through April 20th, 2020. The odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. A sensitivity analysis was conducted according to the study size (>200 or <200) and median age (>55 or <55). Meta-regression analyses were conducted to examine possible sources of heterogeneity. We calculated the diagnostic accuracy of leukocytosis and CRP. Results Eighteen studies with 3278 patients were selected. Fever, leukocytosis, and elevated CRP were associated with poor outcomes (OR (95% CI) 1.63 (1.06–2.51), 4.51 (2.53–8.04), and 11.97 (4.97–28.8), respectively). Leukopenia was associated with a better prognosis (OR 0.56, 95% CI 0.40–0.78). Sensitivity analyses showed similar tendencies. Meta-regression analysis for leukocytosis indicated that age, dyspnea, and hypertension contributed to heterogeneity. The pooled area under the leukocytosis and CRP curves were 0.70 (0.64–0.76) and 0.89 (0.80–0.99), respectively. Conclusion In patients with COVID-19, fever, leukocytosis, and an elevated CRP were associated with severe outcomes. Leukocytosis and CRP on arrival may predict poor outcomes.
【저자키워드】 COVID-19, Meta-analysis, prediction, CRP, Critically ill, White blood cell, Fever, Luekocytosis,