Table 1. Bivariable analysis comparing patient exposures to cefepime-resistant and cefepime-susceptible Pseudomonas aeruginosa, Philadelphia, PA, USA, 2001–2006*.
| Variable | No. (%) case-patients, n = 213 | No. (%) controls, n = 2,316 | OR (95% CI) | p value† |
|---|---|---|---|---|
| General | ||||
| Male sex | 132 (62.0) | 1,307 (56.4) | 1.26 (0.94–1.70) | 0.13 |
| Race, white | 95/207 (45.9) | 1021/2,270 (45.0) | 1.04 (0.77–1.39) | 0.83 |
| Hospital, PPMC | 44 (20.7) | 501 (21.6) | 0.94 (0.65–1.34) | 0.79 |
| Transfer from another facility‡ | 73/212 (34.4) | 509/2,304 (22.1) | 1.85 (1.35–2.52) | <0.001 |
| In ICU at time of culture | 104/202 (51.5) | 831/2,132 (39.0) | 1.66 (1.23–2.24) | 0.001 |
| Prior hospitalization in past 30 d |
60 (28.2) |
526 (22.7) |
1.33 (0.96–1.84) |
0.07 |
| APR-DRG§ | 152 (71.4) | 1,328 (57.5) | 1.84 (1.34–2.55) | <0.001 |
| Concurrent illness | ||||
| Renal insufficiency | 34 (16.0) | 305 (13.2) | 1.25 (0.82–1.86) | 0.25 |
| Malignancy | 22 (10.3) | 358 (15.5) | 0.63 (0.38–0.99) | 0.05 |
| Diabetes | 43 (20.2) | 511 (22.1) | 0.89 (0.62–1.28) | 0.60 |
| Liver disease | 9 (4.2) | 46 (2.0) | 2.18 (0.92–4.58) | 0.04 |
| Congestive heart failure | 2 (0.9) | 37 (1.6) | 0.58 (0.07–2.29) | 0.77 |
| Chronic pulmonary disease | 52 (24.4) | 453 (19.6) | 1.33 (0.94–1.86) | 0.11 |
| Immunosuppressive therapy | 39 (18.3) | 256 (11.1) | 1.80 (1.21–2.63) | 0.004 |
| HIV infection |
5 (2.4) |
54 (2.3) |
1.01 (0.31–2.54) |
>0.99 |
| Antimicrobial drug use¶ | ||||
| Any | 150 (70.4) | 1,458 (63.0) | 1.40 (1.02–1.93) | 0.03 |
| Aminoglycoside | 38 (17.8) | 382 (16.5) | 1.10 (0.74–1.60) | 0.63 |
| Quinolones | 58 (27.2) | 290 (12.5) | 2.61 (1.85–3.65) | <0.001 |
| Extended-spectrum penicillins | 31 (14.6) | 125 (5.4) | 2.99 (1.89–4.60) | <0.001 |
| Extended-spectrum cephalosporin | 80 (37.6) | 401 (17.3) | 2.87 (2.10–3.90) | <0.001 |
| Prior carbapenem | 14 (6.6) | 58 (2.5) | 2.74 (1.38–5.08) | 0.002 |
| Prior anaerobic therapy | 111 (52.1) | 896 (38.7) | 1.72 (1.29–2.31) | <0.001 |
| Prior tetracyclines | 1 (0.5) | 18 (0.8) | 0.60 (0.01–3.85) | >0.99 |
| Prior macrolide | 8 (3.8) | 117 (5.1) | 0.73 (0.31–1.52) | 0.51 |
*OR, odds ratio; CI, confidence interval; PPMC, Penn Presbyterian Medical Center; ICU, intensive care unit; APR-DRG: all-patient refined-diagnosis–related group. Case-patients, those with cefepime-resistant P. aeruginosa; median (interquartile range) duration of stay before culture 8 (4–12) d; and Charlson index 2. Controls, those with cefepime-susceptible P. aeruginosa (interquartile range) duration of stay before culture 4 (4–5) d; and Charlson index 2. †Fisher exact test for categorical variables; Wilcoxon rank-sum test for continuous variables. ‡Outside hospital, long-term care facility, or rehabilitation center. §Patients in the extreme illness category. ¶Inpatient use within previous 30 d before culture during same hospitalization.