Table 1 Clinical characteristics of the study patients
| Â | SSI group | Non-SSI group | p |
|---|---|---|---|
Age (SD), years | 72.2 (9.2) | 72.1 (8.9) | 0.99 |
Sex | Male 10, Female 7 | Male 30, Female 21 |  > 0.99 |
No. of operated segments (SD) | 3.2 (1.8) | 2.2 (1.9) | 0.01* |
Surgery type, n | Decompression 6 Fusion 11 | Decompression 18 Fusion 33 |  > 0.99 |
History of diabetes mellitus, n (%) | 3 (17.6) | 7 (13.7) | 0.70 |
Smoking, n (%) | 1 (5.9) | 6 (11.8) | 0.67 |
Alcohol, n (%) | 4 (23.5) | 22 (43.1) | 0.25 |
NNIS risk index (SD) | 0.76 (0.75) | 0.53 (0.50) | 0.29 |
Preoperative hemoglobin (SD), g/dL | 13.0 (2.0) | 13.1 (1.7) | 0.97 |
Preoperative albumin (SD), g/dL | 3.8 (0.6) | 4.0 (0.3) | 0.27 |
Preoperative Neutrophil percentage (SD) | 67.9 (12.2) | 61.3 (9.4) | 0.05 |
Use of steroids, n (%) | 2 (11.8) | 2 (3.9) | 0.26 |
Use of immunosuppressive agents, n (%) | 1 (5.9) | 1 (2.0) | 0.44 |
Use of biological anti-rheumatic drugs, n (%) | 1 (5.9) | 0 (0) | 0.25 |
Operative time (SD), minutes | 212 (109) | 219 (100) | 0.68 |
Blood loss (SD), ml | 230 (162) | 298 (316) | 0.78 |
Number of blood draws during 14Â days after surgery (SD), n | 4.5 (0.5) | 4.3 (0.6) | 0.16 |