Table 4.

Primary efficacy analysis

	Intervention (n = 681)	Control (n = 663)	Adjusted GEE model†		Unadjusted GEE model‡		Comparison between groups§
			OR*	P	OR*	P	Difference*	P
Death within 30 days	73 (10.7)	96 (14.5)	0.69 (0.47, 0.99)	0.045	0.71 (0.51, 0.98)	0.038	3.8 (0.1, 7.5)	0.046

Values are n (%) unless otherwise indicated; *values in parentheses are 95% confidence intervals. †Analysed by GENMOD (General Mode) with generalized estimating equation (GEE) model, with binary outcome and link function logit adjusted for: age, intestinal ischaemia, faecal, purulent/other peritonitis, chronic obstructive lung disease, ischaemic heart disease, congestive heart failure, chronic renal failure, diabetes, obesity, smoking, ASA grade, and sex. ‡Analysed by GENMOD with GEE model, with binary outcome and link function logit. §The confidence interval for dichotomous variables is the asymptotic Wald confidence limits with continuity correction. Analysis by Fisher’s exact test (lowest 1-sided P value multiplied by 2).