Patient demographics.
| Demographic | 1–2 Stents n = 17,087 | 3–4 Stents n = 1578 | Control (No Stents) n = 707,396 | P Value |
| Age, y | ||||
| <65 | 3087 (18.1%) | 263 (16.7%) | 198,451 (28.1%) | <0.001 |
| 65–69 | 3464 (20.3%) | 322 (20.4%) | 204,913 (29.0%) | |
| 70–74 | 4809 (28.1%) | 452 (28.6%) | 149,913 (21.2%) | |
| 75–79 | 3796 (22.2%) | 360 (22.8%) | 103,084 (14.6%) | |
| 80–84 | 1931 (11.3%) | 181 (11.5%) | 51,035 (7.2%) | |
| Sex | ||||
| Male | 10,365 (60.7%) | 1031 (65.3%) | 297,591 (42.1%) | <0.001 |
| Female | 6722 (39.3%) | 547 (34.7%) | 409,805 (57.9%) | |
| Home discharge | 4524 (26.5%) | 408 (25.9%) | 172,938 (24.4%) | <0.001 |
| Comorbidities | ||||
| Morbid obesity (BMI >30) | 3876 (22.7%) | 322 (20.4%) | 72,924 (10.3%) | <0.001 |
| PVD | 4877 (28.5%) | 459 (29.1%) | 44,211 (6.2%) | <0.001 |
| Chronic kidney disease | 3604 (21.1%) | 315 (20.0%) | 42,801 (6.1%) | <0.001 |
| CHF | 4989 (29.2%) | 413 (26.2%) | 50,449 (7.1%) | <0.001 |
| COPD | 7476 (43.8%) | 597 (37.8%) | 164,959 (23.3%) | <0.001 |
| Diabetes mellitus | 8641 (50.6%) | 783 (49.6%) | 184,501 (26.1%) | <0.001 |
| Hypertension | 16,381 (95.9%) | 1512 (95.8%) | 439,450 (62.1%) | <0.001 |
| Hyperlipidemia | 16,019 (93.7%) | 1483 (94.0%) | 359,138 (50.8%) | <0.001 |
| Substance Use | ||||
| Alcohol | 755 (4.4%) | 65 (4.1%) | 22,456 (3.2%) | <0.001 |
| Smoking | 8718 (51.0%) | 790 (50.1%) | 171,370 (24.2%) | <0.001 |
| Surgical variables | ||||
| 1–2 Levels fusion | 13,143 (76.9%) | 1195 (75.7%) | 550,669 (77.8%) | 0.002 |
| 3–7 Levels fusion | 3312 (19.4%) | 316 (20.0%) | 126,737 (17.9%) | <0.001 |
| 8+ Levels fusion | 84 (0.5%) | 10 (0.6%) | 5262 (0.7%) | 0.001 |
| Decompression | 2078 (12.2%) | 220 (13.9%) | 87,318 (12.3%) | 0.120 |
| Osteotomy | 10 (0.1%) | 0 (0.0%) | 320 (0.0%) | 0.505 |
| Anterior cervical | 5069 (29.7%) | 459 (29.1%) | 213,455 (30.2%) | 0.233 |
| Posterior cervical | 1134 (6.6%) | 107 (6.8%) | 41,787 (5.9%) | <0.001 |
| Combined cervical | 236 (1.4%) | 27 (1.7%) | 9031 (1.3%) | 0.152 |
| Anterior thoracolumbar | 30 (0.2%) | 3 (0.2%) | 2196 (0.3%) | 0.005 |
| Posterior thoracolumbar | 458 (2.7%) | 52 (3.3%) | 22,169 (3.1%) | 0.003 |
| Combined thoracolumbar | 18 (0.1%) | 3 (0.2%) | 1588 (0.2%) | 0.005 |
| Anterior lumbosacral | 512 (3.0%) | 42 (2.7%) | 24,080 (3.4%) | 0.004 |
| Posterior lumbosacral | 9208 (53.9%) | 845 (53.5%) | 374,636 (53.0%) | 0.050 |
| Combined lumbosacral | 537 (3.1%) | 56 (3.5%) | 27,110 (3.8%) | <0.001 |
Abbreviations: BMI, body mass index; CHF, congestive heart failure; COPD, chronic obstructive pulmonary disease; PVD, peripheral vascular disease.