Table 1.
Baseline CAD patient characteristics by billing quintile
| Characteristic∗ | Total N = 170,959 |
Physician billing quintile |
P value† | ||||
|---|---|---|---|---|---|---|---|
| Quintile 1 n = 18,215 | Quintile 2 n = 30,858 | Quintile 3 n = 30,029 | Quintile 4 n = 38,577 | Quintile 5 n = 53,280 | |||
| Age, median (Q1, Q3) | 67 (58,76) | 67 (58,76) | 67 (58,76) | 67 (58,76) | 67 (59,76) | 66 (58,75) | < 0.001 |
| Male sex, n (%) | 122,559 (71.7%) | 13,095 (71.9%) | 22,033 (71.4%) | 21,231 (70.7%) | 27,502 (71.3%) | 38,698 (72.6%) | < 0.001 |
| Income quintile, n (%) | < 0.001 | ||||||
| 1 (lowest) | 32,789 (19.2) | 3724 (20.4) | 5470 (17.7) | 5593 (18.6) | 7149 (18.5) | 10,853 (20.4) | — |
| 2 | 34,807 (20.4) | 3756 (20.6) | 6206 (20.1) | 5888 (19.6) | 7521 (19.5) | 11,436 (21.5) | — |
| 3 | 34,944 (20.4) | 3523 (19.3) | 6144 (19.9) | 6243 (20.8) | 7742 (20.1) | 11,292 (21.2) | — |
| 4 | 35,432 (20.7) | 3581 (19.7) | 6474 (21.0) | 6359 (21.2) | 8254 (21.4) | 10,764 (20.2) | — |
| 5 (highest) | 32,987 (19.3) | 3631 (19.9) | 6564 (21.3) | 5946 (19.8) | 7911 (20.5) | 8935 (16.8) | — |
| Rurality, n (%) | 22,243 (13.0) | 3119 (17.1) | 4871 (15.8) | 3616 (12.0) | 4689 (12.2) | 5948 (11.2) | < 0.001 |
| Prior myocardial infarction, n (%) | 62,887 (36.8) | 6927 (38.0) | 11,919 (38.6) | 10,524 (35.0) | 14,467 (37.5) | 19,050 (35.8) | < 0.001 |
| Prior coronary revascularization, n (%) | 87,473 (51.2) | 8770 (48.1) | 14,699 (47.6) | 13,967 (46.5) | 19,931 (51.7) | 30,106 (56.5) | < 0.001 |
| Renal dysfunction, n (%) | 20,857 (12.2) | 2277 (12.5) | 3487 (11.3) | 3513 (11.7) | 4784 (12.4) | 6873 (12.9) | < 0.001 |
| Previous stroke, n (%) | 11,071 (6.5) | 1298 (7.1) | 1880 (6.1) | 1799 (6.0) | 2427 (6.3) | 3667 (6.9) | < 0.001 |
| Peripheral vascular disease, n (%) | 13,803 (8.1) | 1612 (8.8) | 2379 (7.7) | 2325 (7.7) | 3129 (8.1) | 4358 (8.2) | < 0.001 |
| COPD | 22,948 (13.4) | 2587 (14.2) | 4091 (13.3) | 4068 (13.5) | 5249 (13.6) | 6953 (13.0) | 0.001 |
| Hyperlipidemia, n (%) | 136,460 (79.8) | 14,185 (77.9) | 23,557 (76.3) | 23,296 (77.6) | 30,822 (79.9) | 44,600 (83.7) | < 0.001 |
| Diabetes mellitus, n (%) | 71,590 (41.9) | 7479 (41.1) | 12,115 (39.3) | 12,060 (40.2) | 15,955 (41.4) | 23,981 (45.0) | < 0.001 |
| Hypertension, n (%) | 140,219 (82.0) | 14,797 (81.2) | 24,228 (78.5) | 24,273 (80.8) | 31,738 (82.3) | 45,183 (84.8) | < 0.001 |
COPD, chronic obstructive pulmonary disease; IQR, interquartile range; Q1, first quartile; Q3, third quartile.
∗
Canadian Cardiovascular Society Angina score and left ventricle function not included due to high number of missing values.
†
P values for continuous variables calculated from Kruskal-Wallis tests, and P values for categorical variables calculated from χ2 tests of independence. A 2-tailed P value of < 0.05 was considered statistically significant.