Table 3.

Multivariate Analyses

	ORa	95% CI	P Value
Model 1: insurance carrier
Commercial insurance	1.06	0.62‐1.82	0.82
Age, y	0.87	0.84‐0.89	<0.001
Male sex	0.03	0.02‐0.05	<0.001
HTN	0.59	0.39‐0.87	0.008
DM	0.31	0.19‐0.50	<0.001
Dyslipidemia	0.37	0.25‐0.55	<0.001
Tobacco use	0.70	0.41‐1.21	0.20
Family history of CAD	0.81	0.55‐1.18	0.27
Known CAD	0.24	0.13‐0.42	<0.001
Inability to exercise	0.35	0.21‐0.59	<0.001
Chest pain or dyspnea	0.004	0.002‐0.007	<0.001
Uninterpretable ECGb	7.55	0.50‐114.84	0.15
PCP vs cardiologist	1.30	0.64‐2.64	0.47
Model 2: SES
Upper vs lower SESc	0.90	0.53‐1.52	0.69
Age, y	0.86	0.84‐0.89	<0.001
Male sex	0.03	0.01‐0.05	<0.001
HTN	0.67	0.39‐1.14	0.14
DM	0.16	0.08‐0.31	<0.001
Dyslipidemia	0.51	0.30‐0.87	0.01
Tobacco use	0.74	0.34‐1.61	0.45
Family history of CAD	1.21	0.72‐2.02	0.48
Known CAD	0.32	0.15‐0.67	0.003
Pharmacologic stress	0.27	0.13‐0.56	<0.001
Chest pain or dyspnea	0.005	0.002‐0.01	<0.001
Interpretable ECGb	0.95	0.08‐10.56	0.97
PCP vs cardiologist	1.64	0.66‐4.08	0.29

Abbreviations: CAD, coronary artery disease; CI, confidence interval; DM, diabetes mellitus; ECG, electrocardiogram; HTN, hypertension; LBBB, left bundle branch block; OR, odds ratio; PCP, primary‐care physician; SES, socioeconomic status.

^aORs of inappropriate vs appropriate or uncertain appropriateness use.

^bUninterpretable ECG for myocardial ischemia is defined as LBBB, paced ventricular rhythm, left ventricular hypertrophy with secondary ST‐segment abnormalities, Wolff‐Parkinson‐White pattern, or baseline ST‐segment depression ≥0.5 mm.

^cUpper vs lower socioeconomic status is based on the top (≥$83 000) vs bottom (≤$55 000) quartile of median annual household income for the ZIP code of residence.