Prevention of severe infectious complications after colorectal surgery using oral non-absorbable antimicrobial prophylaxis: results of a multicenter randomized placebo-controlled clinical trial

Table 2 Intention-to-treat analysis of OAP on the risk on primary and secondary outcomes

	OAP	Placebo
	n/N (%)		RR (95% CI)
Deep SSI and/or mortality	4/39 (10.3)	5/39 (12.8)	0.80 (0.23–2.78)
Deep SSI	4/39 (10.3)	5/39 (12.8)	0.80 (0.23–2.78)
30-day mortality	0/39 (0.0)	0/39 (0.0)	N/A
Superficial SSI	1/39 (2.6)	1/39 (2.6)	1.00 (0.06–15.40)
Anastomotic leakage	1/39 (2.6)	2/39 (5.2)	0.50 (0.05–5.29)
Re-operation	3/39 (7.9)	2/39 (5.3)	1.50 (0.27–8.49)
Bacteremia	0/39 (0.0)	0/39 (0.0)	N/A
Infection with HRE	0/39 (0.0)	0/39 (0.0)	N/A
Infection with Clostridium difficile	0/39 (0.0)	0/39 (0.0)	N/A
6-month mortality	0/39 (0.0)	0/39 (0.0)	N/A
	Median (IQR)		P value
In-hospital use of antibiotics, DOT^a	0.0 (0.0–0.0)	0.0 (0.0–4.0)	1.000
Length of stay, days^b	7.0 (5.0–13.0)	6.0 (5.0–12.0)	0.497
Length of ICU stay, days^b	4.0 ^c	0	N/A
	Median delta (IQR)		Pvalue
Quality of life^d
Physical functioning	−5.0 (−15.0–5.0)	−10.0 (−20.0–5.0)	0.124
Social role functioning	0.0 (0.0–12.5)	−12.5 (−25.0–0.0)	0.007
Physical role functioning	0.0 (0.0–25.0)	−12.5 (−93.7–0.0)	0.007
Emotional role functioning	0.0 (0.0–0.0)	0.0 (−25.0–0.0)	0.237
Mental health	4.0 (−1.0–13.0)	0.0 (−7.0–8.0)	0.072
Vitality	5.0 (−5.0–10.0)	−10.0 (−20.0–0.0)	0.002
Pain	0.0(−10.2–10.7)	−11.2 (−23.0–6.1)	0.002
General health perception	7.5 (0.0–15.0)	−5.0 (− 15.0–3.75)	0.014
Change in health	0.0 (0.0–50.0)	0.0 (−25.0–0.0)	0.092

Length of (ICU) stay, quality of life and 6-month mortality were assessed 6 months after surgery, all other outcomes were evaluated 30 days after surgery. DOT, days on therapy; HRE, highly resistant Enterobacteriaceae; ICU, intensive care unit; IQR, interquartile range; N/A, not available; OAP, oral antibiotic prophylaxis; RR, risk ratio; sd, standard deviation; SSI, surgical site infections
^a9 patients in the OAP arm and 10 patients in the placebo arm were treated with antibiotics
^bIncluding all readmissions within 6 months
^cOnly 1 patient was admitted to the ICU
^dDelta was calculated by subtracting baseline scores from scores at 6-month follow-up. Negative delta’s reflect worse perception of quality of life on compared to baseline. Number of completed follow-up questionnaires: 27 (69.2%) OAP, 32 (82.1%) placebo