Table 3. Univariate and multivariate analysis of risk factors associated with ESBL-EC compared with non-ESBL-EC isolates in bacteremic patients.
| Variable | ESBL-EC | Non-ESBL-EC | Univariate analysis | Multivariate analysis | ||
|---|---|---|---|---|---|---|
| (n = 30) | (n = 85) | OR (95% CI) | P value | OR (95% CI) | P value | |
| Age, mean (SD), y | 66.5 (17.2) | 72.3 (10.8) | 0.97 (0.94–1.00) | .04 | ||
| Sex: male | 19 | 37 | 2.22 (0.88–5.87) | .09 | ||
| Healthcare-associated infection | 9 | 31 | 0.75 (0.27–1.97) | .66 | ||
| Nosocomial infection | 21 | 40 | 2.63 (1.00–7.25) | .04 | 1.28 (0.40–4.17) | .678 |
| Nursing home-associated infection | 6 | 3 | 6.69 (1.31–44.50) | .009 | 7.98 (1.56–40.9) | .013 |
| Days to onset of nosocomial infection, median (IQR) | 24 (15–79) | 28 (12–50) | 1.00 (0.99–1.01) | .63 | ||
| Used antibiotic(s) within 30 days | 22 | 28 | 5.51 (2.05–16.22) | < .001 | 5.11 (1.61–16.2) | .006 |
| General anesthesia within 30 days | 7 | 6 | 3.94 (1.02–15.8) | .04 | ||
| Chemotherapy within 30 days | 2 | 11 | 0.48 (0.05–2.43) | .51 | ||
| Radiation within 30 days | 1 | 3 | 0.94 (0.02–12.29) | >.99 | ||
| Immunosuppressants within 30 days | 14 | 21 | 2.64 (1.01–6.93) | .04 | ||
| Intensive care unit admission before infection | 8 | 10 | 2.70 (0.82–8.70) | .08 | ||
| Source of infection: | ||||||
| Urinary tract | 13 | 49 | 0.56 (0.22–1.41) | .20 | ||
| Intra-abdominal | 10 | 22 | 1.43 (0.51–3.81) | .48 | ||
| Catheter-associated | 2 | 2 | 2.93 (0.20–42.2) | .28 | ||
| Soft-tissue | 1 | 1 | 2.86 (0.04–229.6) | .46 | ||
| Pneumonia | 0 | 4 | 0 (0–4.32) | .57 | ||
| Unknown | 4 | 7 | 1.71 (0.34–7.37) | .47 | ||
| Comorbid condition(s): | ||||||
| Malignancy | 11 | 38 | 0.72 (0.27–1.82) | .52 | ||
| Diabetes mellitus | 8 | 19 | 1.26 (0.42–3.56) | .63 | ||
| Connective tissue disease | 7 | 3 | 8.12 (1.69–52.53) | .003 | ||
| Cerebral vascular disease | 5 | 9 | 1.68 (0.40–6.23) | .52 | ||
| Peripheral vascular disease | 3 | 4 | 2.23 (0.31–14.12) | .37 | ||
| Paraplegia or hemiplegia | 6 | 2 | 10.11 (1.67–108.70) | .004 | ||
| Dementia | 6 | 1 | 20.3 (2.30–971.50) | .001 | ||
| Cardiovascular disease | 5 | 15 | 0.93 (0.24–3.08) | >.99 | ||
| Chronic liver disease | 4 | 13 | 0.85 (0.19–3.10) | >.99 | ||
| Renal insufficiency | 4 | 13 | 0.85 (0.19–3.10) | >.99 | ||
| Chronic pulmonary disease | 5 | 8 | 1.91 (0.45–7.37) | .32 | ||
| Leukemia | 4 | 0 | Inf (1.99–Inf) | .004 | ||
| Lymphoma | 2 | 2 | 2.93 (0.20–42.19) | .28 | ||
| Peptic ulcer | 2 | 0 | Inf (0.54–Inf) | .07 | ||
| Charlson comorbidity index, mean (SD) | 4.2 (2.2) | 2.7 (2.1) | 1.34 (1.11–1.62) | .003 | ||
| Charlson comorbidity index >2 | 21 | 33 | 3.63 (1.39–10.18) | .005 | ||
| Indwelling devices: | ||||||
| Peripheral catheterization | 10 | 17 | 1.99 (0.70–5.50) | .21 | ||
| Urinary catheterization | 10 | 11 | 3.32 (1.10–10.07) | .03 | ||
| Oxygen inhalation | 7 | 11 | 2.05 (0.60–6.56) | .24 | ||
| Central venous catheter | 7 | 4 | 6.04 (1.39–30.70) | .007 | ||
| Drainage tube | 2 | 6 | 0.94 (0.09–5.66) | >.99 | ||
| Tracheotomy tube | 2 | 2 | 2.93 (0.20–42.19) | .28 | ||
| Nasogastric tube | 2 | 2 | 2.93 (0.20–42.19) | .28 | ||
| Mechanical ventilation | 2 | 2 | 2.963(0.20–42.19) | .28 | ||
| Continuous hemodiafiltration | 1 | 1 | 2.86 (0.04–229.6) | .46 | ||
ESBL-EC, extended-spectrum beta-lactamase-producing E. coli; non-ESBL-EC, non-extended-spectrum beta-lactamase-producing E. coli; OR, odds ratio; CI, confidential interval; IQR, interquartile range; SD, standard deviation; CCI, Charlson comorbidity index; Inf, infinity.