	Australia		Canada		Norway		UK		Overall
	c	AIC	c	AIC	c	AIC	c	AIC	c	AIC
Baseline model	0.62	54.3	0.58	32.75	0.63	2.53	0.61	115.5	0.61	216
+Charlson	0.62	7.64	0.58	0	0.63	0	0.61	0	0.61	0
+Elixhauser	0.62	1.75	0.58	8.34	0.63	6.17	0.61	1.9	0.61	12.1
+IPD	0.62	0	0.58	0.03	0.63	3.28	0.61	36.7	0.61	93.2

IPD, in-patient days.