Table 2.
Comparison of general data, basic diseases and surgical characteristics between the two groups.
| Characteristic | Infection group (n = 51) | Non-infection group (n = 964) | χ2 | P-value |
|---|---|---|---|---|
| Age < 65 years | 35 | 560 | 2.361 | 0.125 |
| Age ≥ 65 years | 16 | 404 | - | - |
| Male | 23 | 470 | 0.391 | 0.532 |
| Female | 28 | 494 | - | - |
| BMI ≥ 30 | 6 | 35 | 9.874 | 0.002 |
| BMI < 30 | 45 | 929 | - | - |
| History of alcohol consumption | 7 | 112 | 0.838 | 0.360 |
| No history of alcohol consumption | 44 | 852 | - | - |
| Smoking history | 21 | 221 | 11.279 | 0.001 |
| No smoking history | 30 | 743 | - | - |
| ASA grade ≥ 3 | 21 | 163 | 29.823 | 0.000 |
| ASA grade < 3 | 30 | 801 | - | - |
| Hypertension | 11 | 226 | 0.079 | 0.779 |
| No hypertension | 40 | 738 | - | - |
| Diabetes | 18 | 191 | 10.616 | 0.001 |
| No diabetes | 33 | 773 | - | - |
| Anemia | 4 | 38 | 3.902 | 0.025 |
| No anemia | 47 | 926 | - | - |
| Coronary artery disease | 2 | 22 | 0.922 | 0.147 |
| No coronary artery disease | 49 | 942 | - | - |
| COPD | 1 | 5 | 0.232 | 0.139 |
| No COPD | 50 | 959 | - | - |
| Autoimmune diseases | 2 | 8 | 1.442 | 0.219 |
| No autoimmune diseases | 49 | 956 | - | - |
| Cerebrovascular diseases | 1 | 12 | 0.187 | 0.658 |
| No cerebrovascular diseases | 50 | 952 | - | - |
| Liver diseases | 8 | 107 | 0.976 | 0.319 |
| No liver diseases | 43 | 857 | - | - |
| Osteoporosis | 7 | 131 | 0.011 | 0.905 |
| No osteoporosis | 44 | 833 | - | - |
| Cardiovascular events | 3 | 85 | 0.109 | 0.721 |
| No cardiovascular events | 48 | 879 | - | - |
| Duration of surgery ≥ 3 h | 23 | 590 | 8.032 | 0.005 |
| Duration of surgery < 3 h | 28 | 374 | - | - |
| Anterior approach | 4 | 670 | 71.101 | 0.000 |
| Posterior approach | 38 | 590 | - | - |
| Combined approach | 9 | 19 | - | - |
| Intraoperative blood loss ≥ 300 ml | 21 | 410 | 19.985 | 0.000 |
| Intraoperative blood loss < 300 ml | 30 | 554 | - | - |
| Internal fixation present | 49 | 858 | 6.438 | 0.011 |
| Internal fixation absent | 2 | 106 | - | - |
| Postoperative closed drainage ≥ 5d | 9 | 60 | 13.877 | 0.000 |
| Postoperative closed drainage < 5d | 42 | 904 | - | - |
| Incision length ≥ 10 cm | 9 | 78 | 8.744 | 0.003 |
| Incision length < 10 cm | 42 | 886 | - | - |
Statistical Notes: For expected counts (T) ≥ 5, Pearson’s χ2 value was used. For expected counts (1 ≤ T < 5), the continuity-corrected χ2 value was used. For expected counts (T < 1), Fisher’s exact test was directly applied.
BMI = Body Mass Index; ASA = American Society of Anesthesiologists; COPD = Chronic Obstructive Pulmonary Disease.