CRP and COVID-19: Pooled analyses found that among all critically ill COVID-19 patients, mortality was associated with increased baseline LDH (WMD = 129.34 U/L [CI 67.73, 190.94], p < 0.001, I2 = 34.1%), increased CRP (WMD = 45.36 mg/L [CI 23.50, 87.50], p < 0.001, I2 = 35.3%), and decreased platelet levels (WMD = − 30.19 × 109/L [CI − 44.88, − 15.50], p < 0.001, I2 = 0.0%).