Table 2:

Aneurysm characteristics in centers with low (group A) and high (group B) numbers of cases/hospital

	Group A (n = 197)		Group B (n = 542)		P Value
	No.	%	No.	%
Location
ICA	89	45.2	235	43.4	.54
ACA, AcomA	30	15.2	107	19.7
MCA	60	30.5	158	29.2
VB	18	9.1	42	7.7
Aneurysm size (mm)
1–3	31	15.7	100	18.5	.65
3–6	86	43.7	218	40.2
7–10	54	27.4	161	29.7
11–15	26	13.2	63	11.6
Dome-to-neck ratio
≤1.5	109	55.3	278	51.3	.30
>1.5	88	44.7	264	48.7