Table 1.
Predictors of High Vancomycin Minimum Inhibitory Concentration (MIC)
| Variable | No (%) of events with high MICs (n = 57) | No.(%) of events with low MICs (n = 239) | OR (95% CI) | P value |
| Male sex | 39 (68) | 145 (61) | 1.4 (0.8–2.6) | .27 |
| Age > 50 years | 52 (91) | 173 (72) | 4.0 (1.5–10.4) | < .01 |
| Any malignancy | 11 (19) | 70 (29) | 0.6 (0.3–1.2) | .12 |
| Hematologic malignancy | 3 (5) | 34 (14) | 0.3 (0.1–1.1) | .05 |
| Diabetes mellitus | 23 (40) | 93 (39) | 1.1 (0.6–1.9) | .84 |
| Immunosuppressive therapy | 16 (28) | 81 (34) | 0.8 (0.4–1.4) | .40 |
| Chronic cardiovascular disease | 38 (67) | 132 (55) | 1.6 (0.9–3.0) | .11 |
| Chronic liver disease | 18 (32) | 51 (21) | 1.7 (0.9–3.2) | .11 |
| Chronic lung disease | 20 (35) | 80 (33) | 1.1 (0.6–2.0) | .82 |
| Chronic kidney disease | 25 (44) | 85 (36) | 1.4 (0.8–2.5) | .25 |
| Hemodialysis | 13 (23) | 45 (19) | 1.3 (0.6–2.6) | .50 |
| Dementia | 3 (5) | 27 (11) | 0.4 (0.1–1.5) | .15 |
| Transplant recipient | 3 (5) | 19 (8) | 0.6 (0.2–2.3) | .47 |
| SIRS on bacteremia presentation | 42 (88) | 163 (76) | 2.2 (0.9–5.6) | .06 |
| Sepsis on bacteremia presentation | 31 (65) | 87 (41) | 2.7 (1.4–5.1) | < .01 |
| Septic shock on bacteremia presentation | 18 (38) | 47 (22) | 2.2 (1.1–4.2) | .03 |
| Apache II ≥ 5 | 28 (57) | 92 (43) | 1.8 (0.9–3.3) | .08 |
| Charlson score > 5 | 18 (36) | 103 (47) | 0.6 (0.3–1.2) | .17 |
| ICU at time of diagnosis of bacteremia | 15 (26) | 83 (35) | 0.7 (0.4–1.3) | .22 |
| Health care associated bacteremia | 50 (91) | 210 (90) | 1.1 (0.4–3.0) | .86 |
| History of MRSA | 31 (54) | 105 (44) | 1.5 (0.9–2.7) | .16 |
| History of MRSA bacteremia | 20 (35) | 37 (16) | 3.0 (1.6–5.6) | < .01 |
| Any antibiotics in prior 30 days | 43 (77) | 179 (75) | 1.1 (0.6–2.2) | .80 |
| Piperacillin/tazobactam in prior month | 1 (2) | 25 (11) | 0.2 (0.0–1.2) | .02 |
| Daptomycin in prior 30 days | 5 (9) | 3 (1) | 7.9 (1.8–34.0) | < .01 |
| Vancomycin > 48 h in last week | 18 (32) | 26 (11) | 3.8 (1.9–7.6) | < .01 |
| Foreign bodya | 51 (90) | 189 (80) | 2.1 (0.9–5.2) | .08 |
| Joint implant | 10 (18) | 26 (11) | 1.8 (0.8–4.0) | .17 |
| Any endovascular | 48 (84) | 174 (73) | 1.9 (0.9–4.2) | .08 |
| Heart valve | 7 (12) | 9 (4) | 3.6 (1.3–10.0) | .02 |
| Tunneled central line | 9 (16) | 42 (18) | 0.9 (0.4–1.9) | .72 |
| Nontunneled central line | 29 (51) | 85 (36) | 1.9 (1.1–3.4) | .03 |
| Subcutaneous device | 21 (37) | 75 (32) | 1.3 (0.7–2.3) | .44 |
NOTE. Univariate analyses of 296 episodes of MRSA bacteremia to identify factors that are associated with a vancomycin MIC of 2 mg/L. P values of < 0.5 are presented in bold.
a
Includes all foreign bodies, except Foley catheter.