TABLE 2.
Descriptive statistics and adjusted odds ratios for antibiotic exposure in patients with ESBL-producing, AmpC-producing, and susceptible infections in previous 30 days, 90 days, and by antibiotic category
| Time of exposure, drug categorya | No. (%) |
Adjusted relative risk ratio (95% CI)b |
|||
|---|---|---|---|---|---|
| ESBL n = 210 | AmpC n = 94 | Controls n = 900 | ESBL vs control | AmpC vs control | |
| 30 days before culture | |||||
| Any antibiotic | 100 (48) | 32 (34) | 200 (22) | 2.19 (1.48–3.23) | 1.12 (0.65–1.91) |
| Broad-spectrum beta-lactams | 33 (16) | 11 (12) | 52 (6) | 1.98 (1.15–3.40) | 1.88 (0.86–4.11) |
| Third-generation cephalosporins | 14 (7) | 8 (9) | 19 (2) | 2.32 (1.09–4.93) | 4.47 (1.75–11.41) |
| Carbapenems | 3 (1) | 1 (1) | 3 (0) | 2.35 (0.45–12.37) | 2.06 (0.18–23.25) |
| Cefepime and/or BL/BLIs | 24 (11) | 4 (4) | 34 (4) | 2.01 (1.07–3.74) | 0.88 (0.28–2.77) |
| Anaerobic agents | 19 (9) | 3 (3) | 43 (5) | 1.20 (0.65–2.20) | 0.40 (0.12–1.37) |
| Aminoglycosides | 10 (4) | 1 (1) | 22 (2) | 0.89 (0.37–2.12) | 0.37 (0.05–2.98) |
| Fluoroquinolones | 7 (3) | 3 (3) | 12 (1) | 1.62 (0.58–4.50) | 1.71 (0.42–6.89) |
| TMP-SMX | 44 (21) | 19 (20) | 74 (8) | 1.81 (1.11–2.96) | 1.69 (0.88–3.23) |
| 90 days before culture | |||||
| Any antibiotic | 120 (57) | 45 (48) | 289 (32) | 1.91 (1.31–2.79) | 1.03 (0.62–1.73) |
| Broad-spectrum beta-lactams | 49 (23) | 25 (27) | 109 (12) | 1.31 (0.84–2.05) | 1.91 (1.07–3.41) |
| Third-generation cephalosporins | 21 (10) | 20 (21) | 62 (7) | 0.92 (0.53–1.60) | 2.68 (1.45–4.94) |
| Carbapenems | 6 (3) | 4 (4) | 14 (2) | 1.04 (0.37–2.90) | 1.85 (0.53–6.48) |
| Cefepime and/or BL/BLIs | 37 (18) | 11 (12) | 62 (7) | 1.80 (1.07–3.02) | 1.30 (0.60–2.81) |
| Anaerobic agents | 30 (14) | 12 (13) | 80 (9) | 1.08 (0.64–1.78) | 0.96 (0.47–1.98) |
| Aminoglycosides | 13 (6) | 6 (6) | 38 (4) | 0.61 (0.30–1.28) | 1.06 (0.38–2.94) |
| Fluoroquinolones | 14 (7) | 5 (5) | 22 (2) | 1.76 (0.83–3.74) | 1.30 (0.44–3.82) |
| TMP-SMX | 51 (24) | 25 (27) | 101 (11) | 1.53 (0.97–2.41) | 1.62 (0.90–2.92) |
a
BL/BLIs, beta-lactams/beta-lactamase inhibitors; TMP-SMX, trimethoprim-sulfamethoxazole.
b
Multinomial logistic regression was performed controlling for age, sex, previous hospitalization in the last year, presence of an indwelling device, underlying medical conditions, and immunosuppression as defined in Table 1.