Table 1.

Main characteristics of the studies included in the pooled analysis

Study	Setting	Blood sample size, n (% females)	Age, years	Severe disease,%	RDW in severe vs. nonsevere disease, %
Gong et al. [11]	China	189 (48.1)	49±8	14.8	12.75±0.31 vs. 12.22±0.33 (p < 0.01)
Levy et al. [12]	USA	11,095 (41.3)	65±7	23.4	14.20±0.77 vs. 13.50±0.31 (p < 0.001)
Wang et al. [13]	China	161 (48.9)	39±13	18.6	12.59±0.65 vs. 12.29±0.46 (p = 0.02)
Cumulative value	−	−	−	−	14.17±0.55 vs. 13.48±0.36 (p < 0.001)

Values are presented as means ± SD unless otherwise stated. RDW, red blood cell distribution width.