Table 4.

Community & Hospital Characteristics Associated with Early Revision THA (7,945 revisions among 207,256 patients).

	Septic Revision			Aseptic Revision
	Hazard Ratio	95% CI	p-value	Hazard Ratio	95% CI	p-value
Hospital Factors
THA volume
≤200 v. >400	1.22	(0..81,1.84)	0.342	1.33	(1.16,1.52)	<0.001
201–400 v. >400	1.14	(0.75,1.74)	0.488	1.42	(1.24,1.64)	<0.001
Bed size
51–200 v. <50	1.93	(0.95,3.91)	0.070	0.99	(0.82,1.18)	0.869
200–400 v. <50	1.96	(0.96,4.00)	0.064	1.06	(0.88,1.27)	0.570
>400 v. <50	2.13	(1.03,4.40)	0.042	1.19	(0.98,1.44)	0.083
Teaching hospital	1.06	(0.81,1.40)	0.668	1.00	(0.90,1.11)	0.927
Interaction Variables
THA Volume 201–400 * Teaching Hospital	0.99	(0.73,1.34)	0.747	0.97	(0.86,1.09)	0.095
THA Volume >400 * Teaching Hospital	0.80	(0.58,1.13)	0.946	0.79	(0.70,0.90)	0.517
Urban v. Rural	0.80	(0.62,1.05)	0.113	1.06	(0.95,1.19)	0.302
Community Factors
Education
50th v. 25th	0.83	(0.69,1.00)	0.053	0.97	(0.91,1.05)	0.480
75th v. 25th	0.85	(0.70,1.04)	0.116	1.07	(0.99,1.15)	0.075
100th v. 25th	0.83	(0.67,1.03)	0.088	1.06	(0.98,1.14)	0.173
Poverty
50th v. 25th	1.07	(0.88,1.31)	0.491	1.02	(0.95,1.09)	0.596
75th v. 25th	1.02	(0.82,1.26)	0.878	1.06	(0.99,1.14)	0.108
100th v. 25th	1.21	(0.97,1.51)	0.088	1.02	(0.95,1.11)	0.560