Table 3.

Rates of deep surgical site infection in patients with risk factors

Factor	Group 1	Group 2	P Value
Total cohort	11/188 (5.8 %)	0/196 (0 %)	0.0003b
Diabetes mellitus	6/26 (23.0 %)	0/24 (0 %)	0.023a
Lumbar surgery	8/99 (8.0 %)	0/83 (0 %)	0.0082b
Trauma	6/134 (4.4 %)	0/144 (0 %)	0.0118a
Posterior approach	9/126 (7.1 %)	0/141 (0 %)	0.001b
Estimated blood loss over 1,000 g	3/39 (7.6 %)	0/39 (0 %)	0.2403
Duration of operation over 5 h	6/30 (20.0 %)	0/23 (0 %)	0.0303a

A Fisher’s exact test was used to detect differences in the infection rates between the 2 group

^aP < 0.05 and ^b P < 0.01 for the intergroup comparison