Table 1.

Baseline characteristics of participants in modified intention-to-treat population. Values are numbers (percentages) unless stated otherwise

Characteristics	Oral prophylaxis group (n=463)	Placebo group (n=463)
Mean (SD) age (years)	63 (13)	63 (13)
Men	262 (57)	292 (63)
Mean (SD) weight (kg)	74 (15)	75 (15)
Mean (SD) body mass index	26 (4)	26 (4)
ASA physical status classification*:
1	101/462 (22)	101/461 (22)
2	272/462 (59)	260/461 (56)
3	86/462 (18)	94/461 (20)
4	3/462 (1)	6/461 (2)
Medical history:
Hypertension	199 (43)	198 (43)
Diabetes mellitus	69 (15)	71 (15)
Coronary artery disease	32 (7)	56 (12)
Chronic pulmonary disease	22 (5)	33 (7)
Current smoker	71 (15)	78 (17)
Any alcohol intake	34 (7)	39 (8)
Disease related malnutrition	31 (7)	20 (4)
History of multidrug resistant bacteria	2 (1)	3 (1)
Antibiotic use within 3 months before surgery	53 (11)	56 (12)
Adjuvant chemotherapy or radiotherapy	113 (24)	110 (24)
Drugs used at time of surgery:
Corticosteroid	11 (2)	15 (3)
Non-steroidal anti-inflammatory drug	5 (1)	13 (3)
Indication for surgery:
Colorectal cancer	351 (76)	356 (77)
Diverticulitis	78 (17)	70 (15)
Other condition	34 (7)	37 (8)
Skin preparation:
Chlorhexidine-alcohol	43 (9)	48 (10)
Povidone-iodine alcohol	420 (91)	415 (90)
Mechanical bowel preparation:	153 (33)	160 (35)
Polyethylene glycol	64/151 (42)	57/157 (36)
Senna solution	87/151 (58)	100/157 (64)
Retrograde enema	199 (43)	210 (45)

ASA=American Society of Anesthesiology.

Only male sex (P=0.04) and coronary artery disease (P=0.007) differed significantly.

Percentages may not total 100 because of rounding.

^*Data on the ASA physical status class were missing for two participants in the placebo group and one participant in the oral prophylaxis (ornidazole) group.