Patient demographics for during hours vs after hours groups.
| Demographic | During Hours Group | After Hours Group | P Value |
| Age, y, mean ± SD (range) | 55.7 ± 19.8 (16–87) | 55.2 ± 20.1 (2–95) | 0.89 |
| Sex, men, n (%) | 34 (69.4%) | 119 (62.0%) | 0.34 |
| Comorbidity, n (%) | |||
| Malignancy | 10 (20.4%) | 32 (16.7%) | 0.54 |
| Congestive heart failure | 2 (4.1%) | 16 (8.3%) | 0.31 |
| Coronary artery disease | 8 (16.3%) | 23 (12.0%) | 0.42 |
| Chronic obstructive pulmonary disease | 3 (6.12%) | 14 (7.29%) | 0.775 |
| Hypertension | 22 (44.90%) | 91 (47.40%) | 0.756 |
| Hyperlipidemia | 14 (28.57%) | 45 (23.44%) | 0.456 |
| Diabetes mellitus | 14 (28.57%) | 35 (18.23%) | 0.108 |
| Liver disease | 3 (6.12%) | 6 (3.13%) | 0.323 |
| Chronic kidney disease | 6 (12.24%) | 15 (7.81%) | 0.326 |
| Alcohol abuse, n (%) | 3 (6.12%) | 23 (11.98%) | 0.238 |
| Drug abuse, n (%) | 2 (4.08%) | 18 (9.38%) | 0.231 |
| Anticoagulant use, n (%) | 7 (14.29%) | 21 (10.94%) | 0.514 |
| Antiplatelet use, n (%) | 12 (24.49%) | 21 (10.94%) | 0.014 |
| Prior site surgery, n (%) | 11 (22.45%) | 48 (25.00%) | 0.711 |
| Neurological deficit, n (%) | 24 (50.00%) | 84 (44.27%) | 0.476 |
| American Spinal Injury Association impairment scale, n (%) | 0.083 | ||
| A | 4 (8.51%) | 20 (11.05%) | |
| B | 3 (6.12%) | 26 (14.36%) | |
| C | 8 (17.02%) | 28 (15.47%) | |
| D | 24 (51.06%) | 56 (30.94%) | |
| E | 8 (17.02%) | 51 (28.18%) | |
| American Society of Anesthesiologists class, n (%) | 0.062 | ||
| 1 or 2 | 10 (20.41%) | 43 (22.40%) | |
| 3 | 25 (51.02%) | 68 (33.42%) | |
| 4 or 5 | 14 (28.57%) | 81 (42.19%) |