Table 2. Multivariable model of risk factors for cefepime-resistant Pseudomonas aeruginosa infection, Philadelphia, PA, USA, 2001–2006*.
| Variable | Unadjusted OR | Adjusted OR (95% CI) | p value |
|---|---|---|---|
| Prior use of extended-spectrum cephalosporin | 2.87 | 2.18 (1.57–3.04) | <0.001 |
| Prior use of extended-spectrum penicillin | 2.99 | 1.91 (1.22–2.99) | 0.005 |
| Prior use of quinolone | 2.61 | 1.96 (1.38–2.78) | <0.001 |
| Prior use of carbapenem | 2.74 | 1.70 (0.90–3.21) | 0.10 |
| Transfer from outside facility | 1.85 | 1.49 (1.09–2.04) | 0.01 |
| Length of hospital stay before culture | NA | 1.00 (0.99–1.01)† | 0.81 |
*OR, odds ratio; CI, confidence interval; NA, not applicable. No substantive changes were found when above analyses were limited to bloodstream isolates only. †Odds associated with each 1-day increase in hospital stay.