CRP and COVID-19: A previous study found that D-dimer predicts ICU admission less accurately than NLR (multivariable OR: 2.3 vs. 7.2, 95% CI, P < .001).21 However, a study of older (≥60 years) participants revealed that both D-dimer (AUC: 0.730, P < .001) and NLR (AUC: 0.715, P < .001) are equally accurate in predicting COVID-19 patients’ mortality.22 A study has shown that D-dimer has the highest C-index value in comparison with C-reactive protein, procalcitonin, and lactate dehydrogenase.23