Patient characteristics by quartile of facility stress testing rates
| Quartile 1 Lowest rates of stress testing n=5041 | Quartile 2 n=8049 | Quartile 3 n=9337 | Quartile 4 Highest rates of stress testing n=7557 | P values | |
| Stress testing rate (%) | |||||
| Median rate (IQR) | 7.0 (6.0–9.1) | 12.0 (10.8–12.3) | 14.5 (14.1–15.3) | 18.2 (16.6–21.5) | |
| Range | 0.0–9.7 | 9.8–13.2 | 13.3–15.9 | 16.0–25.6 | – |
| Demographics | |||||
| Median age in years (IQR) | 65 (60–74) | 65 (60–73) | 66 (60–74) | 66 (60–74) | <0.001 |
| Race (%) | <0.001 | ||||
| White | 4312 (87.7) | 6969 (88.8) | 8311 (90.2) | 6531 (88.6) | |
| African American | 551 (11.2) | 780 (9.9) | 799 (8.7) | 744 (10.1) | |
| Other | 53 (1.1) | 100 (1.3) | 100 (1.1) | 100 (1.4) | |
| Male (%) | 4931 (97.8) | 7936 (98.6) | 9202 (98.6) | 7383 (98.3) | 0.002 |
| Comorbidities at time of PCI (%) | |||||
| revised Cardiac Risk Index | <0.001 | ||||
| 1 | 2435 (51.3) | 3566 (47.1) | 3971 (45.2) | 3238 (45.5) | |
| 2 | 1441 (30.3) | 2469 (32.6) | 2861 (32.6) | 2410 (33.9) | |
| ≥3 | 875 (18.4) | 1539 (20.3) | 1954 (22.2) | 1472 (20.7) | |
| Congestive heart failure | 1556 (30.9) | 2601 (32.3) | 3123 (33.5) | 2535 (33.8) | 0.001 |
| Cerebrovascular disease | 1050 (20.8) | 1732 (21.5) | 2202 (23.6) | 1790 (23.8) | <0.001 |
| Recent* unstable angina | 632 (12.5) | 1161 (14.4) | 1197 (12.8) | 1004 (13.4) | 0.001 |
| Recent* chest pain or angina | 1752 (34.8) | 2756 (34.2) | 3490 (37.4) | 2806 (37.4) | <0.001 |
| Recent* myocardial infarction | 414 (8.2) | 742 (9.2) | 907 (9.7) | 701 (9.3) | 0.03 |
| Hypertension | 4497 (89.2) | 7252 (90.1) | 8545 (91.5) | 6796 (90.5) | <0.001 |
| Diabetes mellitus | 0.002 | ||||
| Non-insulin dependent | 1491 (29.6) | 2400 (29.8) | 2807 (30.1) | 2335 (31.1) | |
| Insulin dependent | 834 (16.5) | 1488 (18.5) | 1766 (18.9) | 1310 (17.4) | |
| Serum creatinine >2 mg/dL | 604 (12.7) | 1102 (14.6) | 1528 (17.4) | 1174 (16.1) | <0.001 |
| Operative characteristics | |||||
| Median yearly surgical volume (IQR) | 248 (119 -447) | 358 (235–520) | 441 (299–547) | 344 (195–385) | <0.001 |
| Admission status (%) | |||||
| Outpatient | 3108 (61.7) | 4510 (56.0) | 5230 (56.0) | 3961 (52.7) | <0.001 |
| Elective inpatient | 1782 (35.4) | 3225 (40.1) | 3767 (40.3) | 3238 (43.1) | |
| Relative value units for surgery (%) | <0.001 | ||||
| <10 | 2718 (53.9) | 3865 (48.0) | 4606 (49.3) | 3701 (49.3) | |
| 10–20 | 1820 (36.1) | 3091 (38.4) | 3506 (37.6) | 2665 (35.5) | |
| >20 | 503 (10.0) | 1093 (13.6) | 1225 (13.1) | 1144 (15.2) | |
| High-risk† surgery (%) | 443 (9.3) | 802 (10.6) | 963 (11.0) | 816 (11.5) | 0.002 |
| Operation type | <0.001 | ||||
| Digestive | 644 (12.8) | 997 (12.4) | 1137 (12.2) | 968 (12.9) | |
| Eye/ear | 1023 (20.3) | 1526 (19.0) | 1679 (18.0) | 1154 (15.4) | |
| Genital/urinary | 961 (19.1) | 1508 (18.7) | 1888 (20.2) | 1534 (20.4) | |
| Integumentary | 618 (12.3) | 758 (9.4) | 868 (9.3) | 594 (7.9) | |
| Musculoskeletal | 595 (11.8) | 1053 (13.1) | 1150 (12.3) | 1058 (14.1) | |
| Nervous | 332 (6.6) | 382 (4.8) | 447 (4.8) | 364 (4.9) | |
| Respiratory | 186 (3.7) | 336 (4.2) | 377 (4.0) | 1357 (18.1) | |
| Vascular | 624 (12.4) | 1346 (16.7) | 1676 (18.0) | ||
| Other‡ | 58 (1.2) | 143 (1.8) | 115 (1.2) | ||
| Median days between stress test and surgery (IQR) | 55 (29–78) | 49 (23–77) | 50 (24–77) | 50 (23–77) | 0.20 |
| PCI characteristics | |||||
| Median days from PCI to surgery (IQR) | 371 (190–533) | 355 (174–529) | 350 (161–522) | 343 (161–522) | <0.001 |
| Stent type (%) | 0.001 | ||||
| Bare metal | 2434 (48.3) | 4006 (49.8) | 4401 (47.1) | 3594 (47.9) | |
| Drug eluting | 2538 (50.4) | 3921 (48.7) | 4765 (51.0) | 3791 (50.5) | |
| Both | 69 (1.4) | 122 (1.5) | 171 (1.8) | 125 (1.7) | |
SI conversion factors: to convert serum creatinine to µmol/L, multiply the values by 88.4.
*Recent, within 6 months.
†High risk, as defined by revised Cardiac Risk Index: intraperitoneal, intrathoracic, suprainguinal vascular.
‡Other operation types include: general, haematologic and lymphatic, and endocrine.
§Statistics included: analysis of variance, Χ2and Cochrane-Armitage testing.
PCI, percutaneous coronary intervention.