Analysis of risk factors for acute infection—univariate and multivariate analyses
| Risk factor | Logistic regression—effect of single independent risk factor | Multiple logistic regression—effect of each controlling for the others | ||||
|---|---|---|---|---|---|---|
| OR | CI for OR | p Value | OR | CI for OR | p Value | |
| Surgeon group | ||||||
| Neurosurgeon vs Non-specialist | 7.55 | 1.67 to 34.15 | 0.009 | 15.35 | 2.98 to 79.17 | 0.001 |
| Duration | ||||||
| Long ≥60 min vs Short <60 min | 3.75 | 1.26 to 11.14 | 0.017 | 8.20 | 2.34 to 28.79 | 0.001 |
| People in operating room | 0.57 | 0.28 to 1.17 | 0.124 | 0.64 | 0.31 to 1.30 | 0.22 |
| AB prophylaxis | ||||||
| No AB vs AB+In treatment | 5.43 | 1.73 to 17.00 | 0.004 | 8.45 | 2.30 to 31.11 | 0.001 |
AB prophylaxis: the odds of an acute infection in the subgroup of patients with no antibiotic prophylaxis are compared with the odds of an acute infection in patients already receiving antibiotic or those who received antibiotic prophylaxis intraoperatively.
Non-specialist=registrar+trainee.
Significant risk factors for acute infection in addition to number of people in operating room are analysed with logistic regression. Significant p values are in boldface.