Table. 2.
Characteristics of the study cohort by surgery type and spine region
| Fusion N = 2298 | Decompression N = 3495 | |
|---|---|---|
| Cervical | N = 701 | N = 416 |
| Mean (SD) age, years | 45 (8.8) | 45.7 (9.3) |
| Male, n (%) | 476 (67.9) | 333 (80) |
| Median (IQR) time to surgery, months | 14.7 (5.8, 35.5) | 10.2 (4.6, 25.4) |
| Mean (SD) follow-up time, years | 3.3 (2.1) | 3.2 (2.2) |
| Working prior to surgery, n/N (%)* | 233/581 (40.1) | 153/323 (47.3) |
| Lumbar | N = 1597 | N = 3079 |
| Mean (SD) age, years | 41.2 (10.3) | 41.6 (11.4) |
| Male, n (%) | 1176 (73.6) | 2400 (77.9) |
| Median (IQR) time to surgery, months | 32.3 (14.2, 82.3) | 7.8 (4, 21.8) |
| Working prior to surgery, n/N (%)a | 435/1412 (30.8) | 985/2473 (39.8) |
SD standard deviation; IQR interquartile range
aWork status measured in the 31-day period prior to surgery; pre-operative work status was available for 81 % of the cohort with spine region available