Table 2.
Baseline Characteristics Based on Insurance Carrier
| Medicare, N = 448 | Commercial, N = 909 | P Value | |
|---|---|---|---|
| Age, y | 72 ± 8 | 53 ± 10 | <0.001 |
| Male sex | 234 (52) | 563 (59) | 0.02 |
| Chest pain or dyspnea | 243 (54) | 518 (57) | 0.34 |
| HTN | 332 (74) | 430 (47) | <0.001 |
| DM | 141 (31) | 170 (19) | <0.001 |
| Dyslipidemia | 248 (55) | 381 (42) | <0.001 |
| Tobacco use | 50 (11) | 118 (13) | 0.34 |
| Family history of CAD | 139 (31) | 342 (38) | 0.02 |
| Framingham 10‐year CHD risk, % | 19 ± 12 | 10 ± 8 | <0.001 |
| Likelihood of obstructive CAD, %a | 23 ± 9 | 16 ± 13 | <0.001 |
| Pharmacologic stress | 200 (45) | 124 (14) | <0.001 |
| Uninterpretable ECGb | 11 (2.5) | 1 (0.1) | <0.001 |
| BMI, kg/m2 | 29 ± 5 | 30 ± 6 | 0.002 |
| Known CAD | 131 (29) | 114 (13) | <0.001 |
| Physician specialty | <0.001 | ||
| Cardiology | 63 (14) | 47 (5) | |
| Primary care | 385 (86) | 862 (95) | |
| AUC classification | <0.001 | ||
| Appropriate | 318 (71) | 389 (43) | |
| Uncertain | 24 (5) | 18 (2) | |
| Inappropriate | 107 (24) | 502 (55) |
Abbreviations: AUC, appropriate use criteria; BMI, body mass index; CAD, coronary artery disease; CHD, coronary heart disease; DM, diabetes mellitus; ECG, electrocardiogram; HTN, hypertension; LBBB, left bundle branch block; SD, standard deviation.
Continuous variables are presented as mean ± SD. Dichotomous variables are presented as n (%). There were no missing baseline characteristics data.
Based on Diamond and Forrester tables in patients with chest pain or dyspnea.14
Uninterpretable 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.