Table 1.

Characteristics of the selected studies in COVID-19 patients, according to disease severity and survival status.

				Mild Disease or Survivor				Severe Disease or Non-Survivor
First Author, Country	Study Design	Outcome	NOS (Stars)	n	Age (Years)	Gender (M/F)	RDW (%, Mean ± SD)	n	Age (Years)	Gender (M/F)	RDW (%, Mean ± SD)
Asan A., et al. [30], Turkey	R	Severe Non-severe	7	668	41	316/352	13.1 ± 0.9	27	69	15/12	13.8 ± 2.3
Brody H.F., et al. [31], USA	R	Survivor Non-survivor	8	1365	60	723/642	13.8 ± 1.8	276	75	163/113	15.0 ± 2.2
de La Rica R., et al. [32], Spain	R	ICU Non-ICU	7	21	66	18/3	12.2 ± 1.8	27	66	14/13	12.4 ± 1.0
Gong J., et al. [33], China	R	Severe Non-severe	7	161	45	72/89	12.2 ± 0.7	28	64	16/12	12.8 ± 0.6
Henry B.M., et al. [34], USA	P	Severe Non-severe	7	33	49	19/14	14.3 ± 1.4	16	63	10/6	16.4 ± 3.0
Lin S., et al. [35], China	R	Severe Non-severe	7	22	44	11/11	12.4 ± 0.7	46	56	29/17	12.5 ± 0.8
Lorente L., et al. [36], Spain	P	Survivor Non-survivor	7	118	64	53/65	13.4 ± 1.5	25	71	7/18	13.3 ± 2.2
Paliogiannis P., et al. [37], Italy	R	Survivor Non-survivor	7	21	64	12/9	15.6 ± 1.3	9	82	8/1	16.6 ± 1.5
Solmaz I., et al. [38], Turkey	R	ICU Non-ICU	7	1772	47	881/891	13.7 ± 2.8	178	66	96/82	14.2 ± 1.8
Wang C., et al. (a) [39], China	R	Severe Non-severe	7	31	56	18/13	12.4 ± 0.5	12	67	7/5	14.0 ± 1.3
Wang C., et al. (b) [40], China	R	Severe Non-severe	7	35	38	17/18	12.3 ± 0.5	10	43	6/4	12.6 ± 0.7

ICU: intensive care unit; Non-severe: patients with mild or moderate disease; NOS: Newcastle-Ottawa quality assessment scale for case-control studies; P: prospective; R: retrospective; Severe: patients with severe or critical disease. RDW: red blood cell distribution width.