Table 3.

Patient-level variables used in the primary logistic regression modelling to determine geographical differences in outcome between the included centres

	7-day mortality OR (95% CI)	30-day mortality OR (95% CI)	30-day readmission OR (95% CI)	Long length of stay OR (95% CI)
Year (ref 2012)
2007	1.17 (0.84 to 1.63)	1.23 (0.97 to 1.55)	1.10 (0.97 to 1.26)	1.17 (1.05 to 1.30)
2008	1.03 (0.75 to 1.42)	1.30 (1.05 to 1.62)	1.14 (1.00 to 1.29)	1.18 (1.06 to 1.31)*
2009	0.99 (0.71 to 1.36)	1.13 (0.90 to 1.42)	1.08 (0.95 to 1.23)	1.13 (1.02 to 1.25)*
2010	1.10 (0.81 to 1.50)	1.06 (0.85 to 1.32)	1.04 (0.92 to 1.18)	1.01 (0.92 to 1.12)
2011	0.96 (0.70 to 1.31)	0.98 (0.79 to 1.23)	1.04 (0.92 to 1.18)	1.15 (1.04 to 1.27)*
Sex (ref female)
Male	0.86 (0.71 to 1.04)	0.95 (0.83 to 1.08)	1.07 (0.99 to 1.15)	0.93 (0.88 to 0.99)*
Age (ref <60)
60–69	2.08 (1.52 to 2.85)*	1.94 (1.57 to 2.41)*	1.11 (1.00 to 1.23)	1.38 (1.28 to 1.50)*
70–79	2.84 (2.12 to 3.81)*	2.66 (2.17 to 3.25)*	1.21 (1.09 to 1.34)*	1.68 (1.54 to 1.83)*
80+	4.57 (3.44 to 6.05)*	4.52 (3.72 to 5.48)*	1.62 (1.45 to 1.80)*	1.90 (1.74 to 2.09)*
Comorbidity (ref <10)
>10	2.58 (2.07 to 3.21)*	3.79 (3.23 to 4.45)*	2.19 (2.01 to 2.38)*	2.83 (2.65 to 3.08)*
Pathology (ref HPB)
Bowel ischaemia	7.62 (4.48 to 12.96)*	4.59 (3.26 to 6.45)*	1.82 (1.51 to 2.19)*	0.47 (0.40 to 0.56)*
Bowel obstruction	0.45 (0.26 to 0.78)*	0.62 (0.44 to 0.87)	0.73 (0.63 to 0.86)*	0.72 (0.63 to 0.81)*
Peritonitis	3.16 (1.78 to 5.63)*	2.00 (1.37 to 2.93)*	1.16 (0.95 to 1.42)	0.41 (0.34 to 0.48)*
Diverticulitis	1.06 (0.47 to 2.40)	1.18 (0.70 to 1.99)	0.99 (0.74 to 1.32)	1.71 (1.32 to 2.20)*
GI ulcers	1.19 (0.66 to 2.16)	1.56 (1.09 to 2.24)	0.73 (0.61 to 0.89)	0.81 (0.69 to 0.94)*
Hernias	0.65 (0.37 to 1.15)	0.54 (0.37 to 0.78)*	0.54 (0.46 to 0.64)	0.70 (0.61 to 0.80)*
Miscellaneous	2.27 (1.26 to 4.08)*	1.69 (1.15 to 2.47)*	1.14 (0.94 to 1.39)	1.20 (1.01 to 1.42)

The data presented are for the subgroup of patients who underwent surgery (cohort of 19 082 patients).

*p<0.01.