Table 5.

Predictors of Preoperative Cardiac Stress Testing (N = 74,117)

	Odds Ratio	95% CI	P value
Female	1.11	1.02–1.21	0.013
Year of surgery			<0.0001
1997 (ref. = 1996)	1.11	0.88–1.42
1998	1.16	0.91–1.48
1999	1.06	0.82–1.38
2000	1.48	1.15–1.89
2001	1.95	1.54–2.47
2002	1.97	1.56–2.49
2003	2.26	1.81–2.83
2004	2.74	2.20–3.42
2005	3.19	2.57–3.97
2006	3.34	2.69–4.15
2007	3.51	2.84–4.34
2008	2.97	2.38–3.70
Charlson comorbidity			0.001
≥1 (ref.= 0)	1.22	1.09–1.35
Surgical procedure			<0.0001
High risk (ref. =low)	2.42	2.04–2.89
Intermediate risk	2.21	1.88–2.58
Size MSA			<0.0001
< 250,000	0.76	0.67–0.87
250,000–1,000,000	0.84	0.75–0.95
1,000,000+	(Ref)
US region			<0.0001
Northeast (ref. = Pacific West)	1.36	1.13–1.65
Midwest	1.82	1.53–2.15
South	1.15	0.97–1.37
Mountain West	1.37	1.08–1.73
Hospital size			0.021
200–324 beds (ref.= <200)	0.97	0.85–1.10
325–500 beds	1.10	0.97–1.25
>500 beds	1.17	1.03–1.32
Cardiologists per 100,000 population			0.061
Q2 (5.1–<5.9) (ref. = Q1)	1.02	0.89–1.17
Q3 (5.9–<6.9)	1.19	1.03–1.38
Q4 (≥ 6.9)	1.16	0.99–1.37
Medicare expenditures in HRR (2006$)			0.070
Q2 ($6,806–7,579) (ref. = Q1)	1.13	0.99–1.29
Q3 ($7,579–8,528)	1.12	0.97–1.28
Q4 (> $8528)	1.24	1.05–1.45

MSA=metropolitan statistical area; HRR= hospital referral region