Table 2.
Indications for and types of surgery among respondents non-respondents
| Group | All n = 633 |
I Respondents n = 491 |
II Non-respondents n = 130 |
III a Consistent non-respondents n = 12 |
|---|---|---|---|---|
| Indications for surgery, n (%) | ||||
| Lumbar disc herniation | 519 (82) | 399 (81) | 120 (84) | 12 (100) |
| Central spinal stenosis | 94 (15) | 78 (16) | 16 (11) | |
| Lateral spinal stenosis | 39 (6) | 31 (6) | 8 (6) | |
| Segmental instability | 31 (5) | 24 (5) | 7 (5) | |
| Sum b | 683 | 532 | 151 | 12 |
| Types of surgery, n (%) | ||||
| Microdiscectomy | 476 (75) | 362 (74) | 114 (80) | 11 (92) |
| Laminectomy | 111 (17) | 90 (18) | 21 (15) | |
| Instrumented fusion | 30 (5) | 24 (5) | 6 (4) | |
| Chemonucleolysis | 16 (3) | 15 (3) | 1 (1) | 1 (8) |
| Sum | 633 | 491 | 142 | 12 |
a Group III was a subgroup of group II.
b Patients could have more than one indication for surgery.