Table 4.

Pooled Adjusted Odds Ratios for Surgical Site Infection by Operative Time Threshold or Increasing Increments of Time

Pooling subgroup	Number of studies included	Odds ratio (95% CI)	p	I2
Pooled ORs for SSI by operative time thresholds
≥ 1 h vs. <1 h	2	2.33 (1.78, 3.06)	<0.00001	0%
≥ 2 h vs. <2 h	3	1.65 (1.38, 1.98)	<0.00001	6%
≥ 3 h vs. <3 h	11	1.80 (1.52, 2.14)	<0.00001	73%
≥ 4 h vs. <4 h	4	1.62 (1.13, 2.35)	0.010	86%
≥ 5 h vs. <5 h	2	2.71 (1.91, 3.86)	<0.00001	0%
≥ 6 h vs. <6 h	1	7.33 (5.19, 10.35)	<0.00001	Too few studies to inform (< 2)
Pooled ORs for SSI by increasing increments of operative time
Per 1 min	5	1.0028 (0.9995, 1.0062)	0.09	79%
Per 10 min	2	1.05 (1.04, 1.06)	<0.00001	0%
Per 15 min	1	1.13 (1.04, 1.23)	0.004	Too few studies to inform (< 2)
Per 30 min	1	1.17 (1.05, 1.30)	0.004	Too few studies to inform (< 2)
Per 60 min	2	1.37 (0.95, 1.98)	0.09	62%

OR = odds ratio; CI = confidence interval; SSI = surgical site infection.