Table 4.
Univariate and Multivariate Predictors of SSI in Patients after Spinal Surgeries.
| Variables | Patients with SSI (n=21) | Patients without SSI (n=486) | p-Valueb | Univariate analysis | Multivariate analysis | ||||
|---|---|---|---|---|---|---|---|---|---|
| OR | 95% CI | p-Value | OR | 95% CI | p-Value | ||||
| Agea, years | 65.50
(51.25–75.00) |
54.44
(47.00–73.00) |
0.832 | 1.044 | 0.985–1.044 | 0.338 | 0.998 | 0.971–1.025 | 0.874 |
| Female sex | 11 | 257 | 1.000 | 0.978 | 0.361–2.654 | 0.965 | 1.596 | 0.607–4.195 | 0.343 |
| BMIa, kg/m2 | 24.42
(20.40–28.56) |
23.90
(20.65–27.03) |
0.649 | 1.014 | 0.871–1.180 | 0.857 | 1.018 | 0.927–1.118 | 0.709 |
| Obesity, n (%) | 10 | 201 | 0.653 | 1.750 | 0.372–8.240 | 0.479 | – | – | – |
| Hypertension, n (%) | 6 | 172 | 0.643 | 0.757 | 0.226–2.530 | 0.651 | – | – | – |
| Diabetes, n (%) | 2 | 99 | 0.277 | 0.278 | 0.056–1.372 | 0.116 | – | – | – |
| Hyperlipidemia, n (%) | 1 | 29 | 1.000 | 1.020 | 0.113–9.237 | 0.986 | – | – | – |
| Chronic renal failure, n (%) | 1 | 25 | 1.000 | 0.434 | 0.030–6.168 | 0.537 | – | – | – |
| Cancer, n (%) | 3 | 35 | 0.203 | 1.303 | 0.267–6.350 | 0.744 | – | – | – |
| RA, n (%) | 2 | 6 | 0.039# | 1.966 | 0.169–22.913 | 0.589 | – | – | – |
| Steroid use, n (%) | 4 | 14 | 0.005# | 3.398 | 0.688–16.792 | 0.133 | – | – | – |
| Immunosuppressive drugs use, n (%) | 1 | 11 | 0.402 | 0.903 | 0.044–18.411 | 0.947 | – | – | – |
| Smoking, n (%) | 0 | 28 | 0.621 | 0.000 | 0 | 0.998 | – | – | – |
| ASA-PS ≥3, n (%) | 12 | 143 | 0.013# | 2.953 | 1.064–8.195 | 0.038 | 2.566 | 0.961–6.854 | 0.060 |
| JOA scorea | 10.70
(7.00–13.50) |
13.20
(11.00–16.00) |
0.042* | 0.828 | 0.730–0.941 | 0.004 | 0.864 | 0.764–0.977 | 0.020 |
| MRCNS-positive preoperatively, n (%) | 7 | 42 | 0.002# | 3.667 | 1.185–11.352 | 0.024 | 5.060 | 1.787–14.323 | 0.002 |
| Primary surgical lesion—cervical spine, n (%) | 9 | 178 | 0.645 | 0.026 | −0.025–0.047 | 0.563 | – | – | – |
| Instrumentation, n (%) | 15 | 214 | 0.023# | 2.422 | 0.687–8.541 | 0.169 | – | – | – |
| No. of surgical levelsa, n (%) | 4.50
(2.00–5.00) |
4.00
(2.00–5.00) |
0.189 | 1.164 | 0.959–1.412 | 0.124 | – | – | – |
| Duration of surgerya, min | 276.00
(183.25–371.75) |
217.00
(154.25–321.00) |
0.167 | 0.998 | 0.993–1.003 | 0.404 | – | – | – |
| Blood lossa, ml | 355.00
(112.50–737.50) |
150.00
(50.00–400.00) |
0.178 | 1.000 | 1.000–1.001 | 0.297 | – | – | – |
SSI, surgical site infection; OR, odds ratio; CI, confidence interval; BMI, body mass index; RA, rheumatoid arthritis; ASA-PS, American Society of Anesthesiologists Physical Status; JOA, Japanese Orthopaedic Association
aValues are presented as median and interquartile range. bSignificant differences (p<0.05) between values for patients with and without SSI were calculated using the *Mann–Whitney U test. #Chi-square test