Table 2.

Spatial accuracy.

	Pittsburgh Atlas (n=326)	Dartmouth Atlas (n=306)	Median Difference (95% CI)
Localization index, %
Overall percentage
Median	83.6	85.5	−1.9 (−3.5 to −0.3)*
25%–75% IQR	75.3 to 89.0	80.7 to 88.9
Range	27.3 to 96.2	53.2 to 96.0
Acute myocardial infarction
Median	84.7	85.9	−1.2 (−2.7 to 0.2)
25%–75% IQR	77.6 to 89.6	81.4 to 89.9
Range	7.8 to 97.3	51.9 to 96.1
Stroke
Median	84.9	86.9	−2.1 (−3.7 to −0.4)*
25%–75% IQR	76.3 to 89.9	81.0 to 90.0
Range	39.6 to 97.2	48.3 to 96.2
Trauma
Median	79.6	82.2	−2.6 (−5.4 to 0.15)
25%–75% IQR	62.5 to 87.1	72.6 to 87.4
Range	11.3 to 95.8	18.6 to 95.7
Market share index
Overall
Median	14.3	13.4	0.83 (–0.7 to 2.3)
25%–75% IQR	10.2 to 20.4	9.9 to 20.1
Range	2.8 to 57.0	4.6 to 53.4
Acute myocardial infarction
Median	14.1	13.3	0.7 (–0.7 to 2.2)
25%–75% IQR	9.6 to 21.1	9.2 to 20.7
Range	2.8 to 64.5	3.5 to 62.5
Stroke
Median	12.6	12.0	0.6 (−0.8 to 2.0)
25%–75% IQR	9.0 to 18.3	8.7 to 17.9
Range	1.8 to 56.1	3.3 to 51.8
Trauma
Median	16.7	17.5	−0.8 (−2.6 to 1.00)
25%–75% IQR	12.0 to 25.9	12.7 to 24.7
Range	0.0 to 64.4	2.1 to 69.8
Net patient flow
Overall
Median	0.88	0.97	−0.08 (−0.21 to 0.05)
25%–75% IQR	0.52 to 1.48	0.61 to 1.45
Range	0.02 to 10.35	0.20 to 7.83
Acute myocardial infarction
Median	0.97	0.97	0 (−0.14 to 0.14)
25%–75% IQR	0.52 to 1.65	0.62 to 1.62
Range	0.02 to 13.36	0.10 to 15.72
Stroke
Median	0.86	0.92	−0.06 (−0.18 to 0.05)
25%–75% IQR	0.51 to 1.45	0.63 to 1.37
Range	0.02 to 11.29	0.14 to 10.77
Trauma
Median	0.81	0.95	−0.13 (−0.28 to 0.02)
25%–75% IQR	0.33 to 1.56	0.52 to 1.57
Range	0 to 10.86	0.02 to 9.17

CI, Confidence interval.

^*P<.05.