Table 1.

Demographic characteristics of patients included in the metanalysis

Study name	Country	Study design	Total patients	Severe patients	Non severe patients	Age (median)	Age (median) severe	Age (median) non‐severe
Guan W 17	China	R	1099	173	926	47	52	45
Huang C 18	China	P	41	13	28	49	49	49
Wang D 4	China	R	138	36	102	56	66	51
Zhou F 3	China	R	191	54	137	56	69	52
Yang X 5	China	P	52	32	20	52	65	52
Han H 19	China	R	94	45	49	—	—	—
Tang N 20	China	R	183	21	162	54	64	52
Wu C 21	China	R	201	84	117	51	59	48
Xiong Z 22	China	R	421	59	362	52	56	51
Sun Y 23	China	R	63	19	44	47	60	42
Yang Q 24	China	R	136	33	103	56	64	53
Israelsen SB 25	Netherland	R	175	27	148	71	68	73
Total			2794	596	2198	50.1 a	54.5 a	48.8 a

Abbreviations: P, prospective; R, retrospective.

^a Calculated weighted mean.