Prevalence and Risk Factors Comparison of Anterior and Posterior Intracranial Arterial Stenosis

Table 1

Weighted prevalent rates and 95% CIs of ICAS by the anatomic location.

Age	Prevalence and 95% CI of anterior circulation				Prevalence and 95% CI of posterior circulation
	Total	Subtotal	ACA	MCA	Subtotal	PCA	VA	BA
Population free of stroke
35∼	8.6 (6.9∼10.3)	6.9 (5.3∼8.4)	5.4 (4.0∼6.9)	3.3 (2.2∼4.4)	2.4 (1.4∼3.4)	0.2 (0.0∼0.5)	2.2 (1.3∼3.1)	—
45∼	10.9 (8.9∼12.9)	10.0 (8.1∼11.9)	7.2 (5.5∼8.9)	5.7 (4.2∼7.2)	1.6 (0.8∼2.5)	0.2 (0.0∼0.6)	0.9 (0.3∼1.6)	0.6 (0.1∼1.1)
55∼	16.8 (14.3∼19.3)	15.5 (13.1∼17.9)	10.2 (8.1∼12.3)	10.7 (8.5∼12.8)	4.9 (3.4∼6.4)	1.9 (0.9∼2.8)	2.9 (1.7∼4.1)	0.7 (0.1∼1.3)
65∼	22.8 (18.7∼27.0)	19.1 (15.2∼23.1)	12.4 (8.9∼15.9)	13.1 (9.6∼16.7)	10.1 (6.9∼13.3)	2.3 (0.6∼3.9)	7.9 (5.0∼10.8)	2.9 (1.0∼4.7)
75∼	23.1 (17.3∼29.0)	18.2 (12.7∼23.7)	10.5 (5.9∼15.1)	13.6 (8.5∼18.6)	12.1 (7.2∼16.9)	2.5 (0.1∼5.0)	9.5 (5.1∼13.9)	3.2 (0.4∼5.9)
Total	13.8 (12.6∼14.9)	11.9 (10.8∼13.0)	8.2 (7.2∼9.1)	7.5 (6.6∼8.4)	4.2 (3.5∼4.9)	1.0 (0.6∼1.3)	3.0 (2.4∼3.6)	0.8 (0.5∼1.1)
for trend	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001
Population with history of stroke
35∼	—	—	—	—	—	—	—	—
45∼	—	—	—	—	—	—	—	—
55∼	32.7 (19.5∼45.8)	31.3 (18.1∼44.4)	25.0 (12.2∼37.8)	19.5 (7.4∼31.6)	21.4 (9.0∼33.8)	13.2 (2.4∼23.9)	17.5 (5.7∼29.3)	5.7 (0.0∼13.4)
65∼	32.3 (20.9∼43.7)	25.4 (14.3∼36.5)	17.0 (6.9∼27.1)	18.5 (8.2∼28.9)	22.8 (11.9∼33.7)	10.2 (1.7∼18.7)	17.0 (6.9∼27.1)	8.3 (0.5∼16.2)
75∼	38.1 (23.4∼52.8)	27.8 (13.1∼42.4)	21.2 (7.3∼35.2)	21.2 (7.3∼35.2)	29.7 (15.0∼44.5)	7.1 (0.0∼16.7)	25.7 (11.2∼40.2)	10.3 (0.0∼21.4)
Total	32.9 (25.7∼40.2)	27.0 (19.9∼34.2)	20.0 (13.3∼26.7)	18.8 (12.2∼25.4)	23.4 (16.4∼30.4)	10.0 (4.6∼15.4)	18.8 (12.2∼25.4)	7.7 (2.9∼12.5)
for trend	<0.0001	0.198	0.959	0.729	0.189	0.715	0.203	0.137
Overall population
35∼	8.6 (6.9∼10.3)	6.9 (5.3∼8.4)	5.4 (4.0∼6.9)	3.3 (2.2∼4.4)	2.4 (1.4∼3.4)	0.2 (−0.1∼0.5)	2.2 (1.3∼3.1)
45∼	10.9 (8.9∼12.8)	9.9 (8.0∼11.8)	7.2 (5.5∼8.9)	5.6 (4.1∼7.1)	1.6 (0.8∼2.5)	0.2 (−0.1∼0.6)	0.9 (0.3∼1.6)	0.6 (0.1∼1.1)
55∼	17.6 (15.2∼20.1)	16.2 (13.8∼18.6)	10.9 (8.8∼13.0)	11.1 (9.0∼13.2)	5.7 (4.2∼7.3)	2.4 (1.3∼3.5)	3.6 (2.3∼4.9)	0.9 (0.2∼1.6)
65∼	24.2 (20.3∼28.1)	20.0 (16.2∼23.7)	12.8 (9.5∼16.0)	13.6 (10.3∼16.9)	11.9 (8.7∼15.1)	3.3 (1.5∼5.1)	8.7 (5.9∼11.5)	3.5 (1.6∼5.4)
75∼	25.7 (20.2∼31.2)	19.7 (14.5∼25.0)	12.0 (7.6∼16.4)	14.1 (9.4∼18.8)	15.2 (10.3∼20.0)	3.2 (0.7∼5.7)	11.6 (7.2∼16.0)	4.2 (1.3∼7.0)
Total	14.6 (13.5∼15.8)	12.5 (11.5∼13.6)	8.6 (7.7∼9.5)	7.9 (7.0∼8.8)	5.0 (4.3∼5.8)	1.3 (0.9∼1.7)	3.6 (3.0∼4.2)	1.1 (0.7∼1.4)
for trend	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001	<0.0001