Table 1.
Bivariate Comparisons of Demographics, Clinical Characteristics, and Outcomes Between Patients Receiving Vancomycin or Vancomycin + Cefepime
| Covariate | Vancomycina (n = 129) | Vancomycin + Cefepimea (n = 229) | P Value |
|---|---|---|---|
| Demographics | |||
| Age, y | 56 (48–66.5) | 61 (53.5–71) | .001 |
| Male | 86 (66.7) | 146 (63.8) | .580 |
| Race | .548 | ||
| African American | 105 (81.4) | 180 (78.6) | |
| Caucasian | 20 (15.5) | 45 (19.7) | |
| Hispanic | 2 (1.6) | 3 (1.3) | |
| Other/unknown | 2 (1.6) | 1 (0.4) | |
| Comorbidities & medical history | |||
| Myocardial infarction | 4 (3.1) | 20 (8.7) | .047 |
| Heart failure | 26 (20.2) | 58 (25.3) | .268 |
| Peripheral vascular disease | 27 (20.9) | 43 (18.8) | .622 |
| Cerebrovascular disease | 18 (14.0) | 45 (19.7) | .174 |
| Dementia | 8 (6.2) | 36 (15.7) | .008 |
| Chronic pulmonary disease | 25 (19.4) | 66 (28.8) | .049 |
| Chronic obstructive pulmonary disease | 21 (16.3) | 59 (25.8) | .039 |
| Asthma | 5 (3.9) | 12 (5.2) | .560 |
| Connective tissue disease | 19 (14.7) | 24 (10.5) | .235 |
| Peptic ulcer disease | 2 (1.6) | 5 (2.2) | 1.000 |
| Liver disease | 25 (19.4) | 31 (13.5) | .144 |
| Mildb | 23 (17.8) | 27 (11.8) | .114 |
| Moderate/severec | 2 (1.6) | 4 (1.7) | 1.000 |
| Diabetes | 47 (36.6) | 89 (38.9) | .649 |
| With end-organ damage | 37 (28.7) | 56 (24.5) | .381 |
| Hemiplegia | 3 (2.3) | 5 (2.2) | 1.000 |
| Moderate/severe renal diseased | 41 (31.8) | 86 (37.6) | .273 |
| Chronic hemodialysis | 29 (22.5) | 62 (27.1) | .338 |
| Solid tumor without metastasis | 2 (1.6) | 5 (2.2) | 1.000 |
| Leukemia | 0 | 0 | — |
| Lymphoma | 0 | 0 | — |
| Metastatic solid tumor | 5 (3.9) | 8 (3.5) | 1.000 |
| HIV | 5 (3.9) | 7 (3.1) | .679 |
| AIDS | 3 (2.3) | 2 (0.9) | .261 |
| Charlson comorbidity index | 2 (1–5) | 3 (1–5) | .303 |
| Intravenous drug use | 25 (19.4) | 29 (12.7) | .088 |
| Prior hospitalization (90 d) | 48 (37.2) | 97 (42.4) | .341 |
| Prior IV vancomycin (90 d) | 31 (24.0) | 51 (22.3) | .704 |
| Prior MRSA infection (1 y) | 26 (20.2) | 28 (12.2) | .044 |
| Clinical data | |||
| Admitted from: | .011 | ||
| Home | 98 (76.0) | 146 (63.8) | .017 |
| Nursing facility | 20 (15.5) | 68 (29.7) | .003 |
| Transferred from another hospital | 11 (8.5) | 15 (6.6) | .489 |
| Weight, kg | 75 (66.8–87.5) | 76.9 (65.1–91.6) | .541 |
| Creatinine clearance,e,f mL/min | 72.9 (49.2–98.1) | 56.5 (33.2–89.2) | .009 |
| Acute kidney injuryf | 34 (26.4) | 84 (36.7) | .046 |
| APACHE II scoref | 13 (8–19) | 20 (15–27) | <.001 |
| Neutropeniaf | 0 | 1 (0.4) | 1.000 |
| Infection data | |||
| Vancomycin MIC,g mg/L | .834 | ||
| 2 | 50 (38.8) | 96 (41.9) | |
| 1 | 78 (60.5) | 131 (57.2) | |
| ≤0.5 | 1 (0.8) | 2 (0.9) | |
| Polymicrobial BSI | 0 | 16 (7.0) | .001 |
| BSI source | |||
| Endovascular | 20 (15.5) | 64 (27.9) | .008 |
| Infective endocarditis | 20 (15.5) | 54 (23.6) | .070 |
| Other endovascular | 0 | 11 (4.8) | .009 |
| Intra-abdominal | 0 | 1 (0.4) | 1.000 |
| Lower respiratory tract | 6 (4.7) | 72 (31.4) | <.001 |
| Bone/joint | 30 (23.3) | 23 (10.0) | .001 |
| Invasive prosthetic device | 7 (5.4) | 13 (5.7) | .921 |
| Skin/soft tissue | 39 (30.2) | 37 (16.2) | .002 |
| CNS abscess | 5 (3.9) | 4 (1.7) | .293 |
| Intravenous catheter | 24 (18.6) | 49 (21.4) | .529 |
| Urinary | 3 (2.3) | 6 (2.6) | 1.000 |
| Unknown | 10 (7.8) | 23 (10.0) | .472 |
| Treatment data | |||
| Infectious diseases consult | 103 (79.8) | 197 (86.0) | .128 |
| Source control pursued | 57 (44.2) | 80 (34.9) | .084 |
| Vancomycin TDM target | .015 | ||
| Trough concentration 15–20 mg/L | 115 (89.1) | 181 (79.0) | |
| AUC 400–600 mg*h/L | 14 (10.9) | 48 (21.0) | |
| Cefepime dose, mg | — | ||
| 1000 | — | 120 (52.4) | |
| 2000 | 109 (47.6) | ||
| Cefepime dose interval | |||
| Every 6 h | 2 (0.9) | ||
| Every 8 h | 95 (41.5) | ||
| Every 12 h | — | 52 (22.7) | — |
| Every 24 h | 62 (27.1) | ||
| Post-hemodialysis | 18 (7.9) | ||
| Inpatient vancomycin duration, d | 6 (4–10) | 5 (4–9) | .071 |
| Inpatient cefepime duration (n = 229), d | — | 3 (2–4) | — |
| Switched to daptomycin | 36 (27.9) | 70 (30.6) | .597 |
| Switched to ceftaroline | 8 (6.2) | 25 (10.9) | .139 |
| Switched to linezolid | 8 (6.2) | 13 (5.7) | .839 |
| Switched to alternative anti-MRSA therapy before day 5 | 8 (6.2) | 22 (9.6) | .264 |
| Total duration inpatient antibiotics, d | 9 (5–18) | 9 (6–13.5) | .335 |
| Outcomes | |||
| Microbiologic failure | 49 (38.0) | 58 (25.3) | .012 |
| BSI duration ≥7 d | 40 (31.0) | 43 (18.8) | .008 |
| 60-d MRSA BSI recurrence | 15 (11.6) | 19 (8.3) | .302 |
| 30-d mortality | 10 (7.8) | 47 (20.5) | .002 |
| BSI duration, d | 4 (3–7) | 3 (2–5.5) | .003 |
| LOS post–BSI onset, d | 13 (8–21) | 11 (7–17) | .064 |
| Vancomycin-associated nephrotoxicityh | 7 (5.4) | 12 (5.2) | .940 |
| Neurotoxicity attributed to antibiotic(s)i | 0 | 1 (0.4) | 1.000 |
| Clostridium difficile infectionj | 2 (1.6) | 8 (3.5) | .341 |
Abbreviations: APACHE II, Acute Physiology and Chronic Health Evaluation II; AUC, area under the concentration time curve; BSI, bloodstream infection; CNS, central nervous system; IV, intravenous; LOS, length of stay; MIC, minimum inhibitory concentration; MRSA, methicillin-resistant Staphylococcus aureus; TDM, therapeutic drug monitoring.
aData presented as number (percentage) or median (interquartile range).
bMild liver disease defined as chronic hepatitis without cirrhosis.
cSevere liver disease defined as portal hypertension or cirrhosis.
dModerate/severe renal disease defined as chronic kidney disease stage 3 or greater or receiving chronic dialysis.
eCalculated using the Cockroft-Gault formula using actual body weight for body mass index <30 and adjusted body weight for body mass index >30.
fAt time of index MRSA blood culture.
gAutomated susceptibility testing performed by Microscan or Phoenix.
hVancomycin-associated nephrotoxicity defined as a serum creatinine increase of 0.5 mg/L and 50% from baseline on 2 consecutive measurements from initial vancomycin dose to 72 hours after the last dose.
iNeurotoxicity defined as seizure, encephalopathy, or altered mental status specifically attributed to vancomycin and/or cefepime by treating physician(s).
j Clostridium difficile infection defined as signs/symptoms along with positive laboratory test at least 48 hours after initiation of study antibiotics.