Table 3.

Intra operative factors associated with SSI

Variable	Cases	Controls	p value	Odds ratio	95% confidence interval
Nature of operation
Elective	33	30
Emergency	14	17	0.5104	1.336	0.5634 to 3.167
Type of anaesthesia
General anaesthesia	17	20
Spinal anaesthesia	30	27	0.5265	0.765	0.334 to 1.7539
Surgeon
Assistant Professor	36	28
Associate Professor	11	19	0.0767	2.221	0.9101 to 5.419
Use of drain
Yes	21	15
No	26	32	0.203	1.723	0.7432 to 3.995
Wound classification
Clean	18	21
Clean contaminated	18	15	0.478	0.714	0.282 to 1.811
Contaminated	7	8	0.973	0.979	0.297 to 3.232
Dirty	4	3	0.592	0.643	1.267 to 3.261
Suture
Nylon	2	2
Ethilon	20	10	0.5123	0.5	0.0611 to 4.0907
Staples	10	25	0.379	2.5	0.3084 to 20.267
Vicryl	15	10	0.7061	0.667	0.0803 to 5.537
Duration of operation
<3 hrs	33	39
≥3 hrs	14	8	0.1438	0.4835	0.1806 to 1.294
Number of people in theatre
≤6	40	44
≥7	7	3	0.1809	0.3896	0.0943 to 1.6098

Chi-square test was used to compare the cases and controls. P<0.05 considered as significant.