The Effect of Smoking on COVID-19 Symptom Severity: Systematic Review and Meta-Analysis

Table 4

The relationship between smoking status and the severe COVID-19.

Studies	Current smokers with severe COVID-19			Nonsmokers with severe COVID-19
Authors	Event	Total	%	Event	Total	%
CDC report [4]	5	96	8.3	419	6901	60.7
Goyal et al. [12]	6	20	30.0	124	373	33.2
Guan et al. [13]	29	137	21.1	134	927	14.4
Mo et al. [15]	4	6	66.6	81	149	54.3
Wang et al. [18]	7	16	43.7	18	109	16.5
Wan et al. [19]	1	9	11.1	39	126	30.9
Yang et al. [20]	0	2	0	32	50	64.0
Zhang et al. [22]	2	2	100	58	138	42.0
Zhang et al. [23]	6	6	100	24	114	21.0
Zhou et al. [24]	5	11	45.4	49	180	27.2
Total	65	305	21.3	978	9067	10.7