Table 1 Characteristics of the study population according to surgical procedures (N (%))
|  | Overall (N = 167,106) | Resection of spinal cord tumor (N = 5187) | Discectomy (N = 24,595) | Decompression surgery (N = 84,540) | Arthrodesis surgery (N = 52,784) | p-valuea | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Age, years; mean [SD] | 64.1 | [14.3] | 57.1 | [15.8] | 50.2 | [17.0] | 68.2 | [11.3] | 64.8 | [12.8] | <0.001 |
 ≤49 | 26,449 | (15.8) | 1607 | (31.0) | 12,395 | (50.4) | 5663 | (6.7) | 6784 | (12.9) | <0.001 |
 50–59 | 24,253 | (14.5) | 993 | (19.1) | 4088 | (16.6) | 10,937 | (12.9) | 8235 | (15.6) |  |
 60–69 | 45,030 | (26.9) | 1307 | (25.2) | 4269 | (17.4) | 23,881 | (28.2) | 15,573 | (29.5) |  |
 70–79 | 54,107 | (32.4) | 1011 | (19.5) | 2902 | (11.8) | 32,353 | (38.3) | 17,841 | (33.8) |  |
 ≥80 | 17,267 | (10.3) | 269 | (5.2) | 941 | (3.8) | 11,706 | (13.8) | 4351 | (8.2) |  |
Sex | |||||||||||
 Male | 98,445 | (58.9) | 2590 | (49.9) | 15,866 | (64.5) | 53,808 | (63.6) | 26,181 | (49.6) | <0.001 |
 Female | 68,661 | (41.1) | 2597 | (50.1) | 8729 | (35.5) | 30,732 | (36.4) | 26,603 | (50.4) |  |
Level of surgery | |||||||||||
 Cervical | 35,042 | (21.0) | 564 | (10.9) | 357 | (1.5) | 24,596 | (29.1) | 9525 | (18.0) | <0.001 |
 Thoracic | 3582 | (2.1) | 465 | (9.0) | 345 | (1.4) | 822 | (1.0) | 1950 | (3.7) |  |
 Lumbosacral | 10,9669 | (65.6) | 884 | (17.0) | 23,266 | (94.6) | 50,326 | (59.5) | 35,193 | (66.7) |  |
 Unspecified | 18,813 | (11.3) | 3274 | (63.1) | 627 | (2.5) | 8796 | (10.4) | 6116 | (11.6) |  |
History of cardiac disease | 12,332 | (7.4) | 180 | (3.5) | 833 | (3.4) | 7356 | (8.7) | 3963 | (7.5) | <0.001 |
Diabetes | 27,052 | (16.2) | 453 | (8.7) | 2367 | (9.6) | 15,925 | (18.8) | 8307 | (15.7) | <0.001 |
Hypertension | 32,753 | (19.6) | 740 | (14.3) | 2511 | (10.2) | 18,947 | (22.4) | 10,555 | (20.0) | <0.001 |
History of stroke | 3807 | (2.3) | 70 | (1.3) | 217 | (0.9) | 2337 | (2.8) | 1183 | (2.2) | <0.001 |
Hemodialysis | 3340 | (2.0) | 65 | (1.3) | 147 | (0.6) | 1638 | (1.9) | 1490 | (2.8) | <0.001 |
Blood transfusion | 10,382 | (6.2) | 265 | (5.1) | 100 | (0.4) | 2091 | (2.5) | 7926 | (15.0) | <0.001 |
Teaching institution | 35,821 | (21.4) | 2891 | (55.7) | 3185 | (12.9) | 16,652 | (19.7) | 13,093 | (24.8) | <0.001 |
Length of stay, days, median [IQR] | 21 | [16–30] | 23 | [17–33] | 16 | [12–22] | 21 | [16–28] | 25 | [19–37] | <0.001 |