LAUSR

Red blood cell distribution width (RDW) was frequently assessed in COVID‐19 infection and reported to be associated with adverse outcomes. However, there was no consensus regarding the optimal cutoff value for RDW. Records of 98 patients with COVID‐19 from the First People's Hospital of Jingzhou were reviewed. They were divided into two groups according to the cutoff value for RDW on admission by receiver operator characteristic curve analysis: ≤11.5% (n = 50) and >11.5% (n = 48). The association of RDW with the severity and outcomes of COVID‐19 was analyzed. The receiver operating characteristic curve indicated that the RDW was a good discrimination factor for identifying COVID‐19 severity (area under the curve = 0.728, 95% CI: 0.626–0.830, p < 0.001). Patients with RDW > 11.5% more frequently suffered from critical COVID‐19 than those with RDW ≤ 11.5% (62.5% vs. 26.0%, p < 0.001). Multivariate logistic regression analysis showed RDW to be an independent predictor for critical illness due to COVID‐19 (OR = 2.40, 95% CI: 1.27−4.55, p = 0.007). A similar result was obtained when we included RDW > 11.5% into another model instead of RDW as a continuous variable (OR = 5.41, 95% CI: 1.53−19.10, p = 0.009). RDW, as an inexpensive and routinely measured parameter, showed promise as a predictor for critical illness in patients with COVID‐19 infection. RDW > 11.5% could be the optimal cutoff to discriminate critical COVID‐19 infection.