Table 2.

Association between smoking and SSI by subgroups of current smoking, follow-up duration, and CDC-defined SSI.

Studies included	No. of reports	OR (95% CI)	P	Heterogeneity
				Q	P	I2, %
All studies	16	1.62 (1.32–1.97)	0.02	20.3	0.16	26
(1) Current smoking	8	1.77 (1.25–2.51)	0.002	13.95	0.05	50
(2) Follow-up ≥1 year	6	1.90 (1.41–2.57)	<0.00001	3.92	0.56	0
(3) SSI following CDC	8	1.85 (1.47–2.33)	<0.00001	7.05	0.42	1
(1) + (2) + (3)	3	2.13 (1.54–2.94)	<0.00001	0.44	0.80	0