TABLE 3.

Surgery Characteristics of Cases and Controls

Characteristic (nm = Cases/Controls)	Cases n = 146	Controls n = 323	OR (95% CI)	P
Any antibiotic prophylaxis (%) (nm = 7/22)	87.8	87	1.068 (0.58, 1.97)	0.83
Correct antibiotic prophylaxis (%) (nm = 7/22)	74.8	76.4	0.92 (0.57, 1.47)	0.72
Emergency procedure (%)	14.4	9.6	1.58 (0.87, 2.87)	0.13
Type of surgery (%)
Gastroesophageal	17.8	31.3	Reference	—
Hepatopancreatobiliary	33.6	39.3	1.50 (0.87, 2.58)	0.14
Small bowel	25.3	14.2	3.13 (1.69, 5.77)	0.0003
Colorectal	23.3	15.2	2.70 (1.46, 4.99)	0.0017
Surgical complexity (work RVUs; mean ± SD) (nm = 0/11)	29.2 ± 12.7	24.1 ± 11.3	1.036 (1.019, 1.053)	<0.001
Laparoscopic procedure (%)	14.4	50.2	0.17 (0.10, 0.28)	<0.001
Wound class (%)
1	4.1	9	Reference	—
2	78.1	76.8	2.22 (0.89, 5.52)	0.085
3	11.6	11.8	2.16 (0.76, 6.20)	0.15
4	6.2	2.5	5.44 (1.48, 19.97)	0.011
Length of surgery (h, mean ± SD)	3.4 ± 2.1	2.5 ± 1.6	1.34 (1.20, 1.50)	<0.001
Estimated blood loss (mL, mean ± SD) (nm = 4/31)	468.6 ± 740.4	286.1 ± 525.5	1.001 (1.00, 1.001)	0.0096
Intraoperative transfusion (%)	13.7	8.7	1.67 (0.91, 3.087)	0.10

RVUs indicates relative value units; nm, number missing; SD, standard deviation; CI, confidence interval.