Table 4.

Covariates included in the Cox proportional hazards regression model

Covariate	Relative risk	95% confidence interval	P-value
ASA grade 4	4.89	2.22–10.79	0.0001
ASA grade 5	22.89	2.77–188.90	0.0038
Non-operative management	3.71	1.08–12.66	0.0377
Creatinine (mmol/l)	1.0077	1.00–1.01	0.0026
Sernbo score <15	3.845	1.63–9.09	0.0023