TABLE 5.
Multivariable, Log-Binomial Regression Analysis Modeling Inappropriateness of Empiric Antimicrobial Therapy for Each Episode of Infection
| Model 1* |
Model 2** |
|||
|---|---|---|---|---|
| Variables | RR (95%CI)†‡ | p ‡ | RR (95%CI)†‡ | p ‡ |
| Age, y | ||||
| Q2 (42–54) | 1.0 (0.93–1.2) | 0.50 | ||
| Q3 (55–65) | 1.1 (0.94–1.2) | 0.33 | ||
| Q4 (≥66) | 1.1 (0.99–1.2) | 0.085 | ||
| Prior transfusion | 0.99 (0.90–1.1) | 0.79 | ||
| Nosocomial | 1.0 (0.88–1.1) | 0.96 | ||
| APACHE II score during infection | ||||
| Q2 (10–15) | 1.0 (0.93–1.2) | 0.50 | ||
| Q3 (16–20) | 1.1 (0.94–1.2) | 0.39 | ||
| Q4 (≥21) | 0.91 (0.80–1.04) | 0.16 | ||
| WBC during infection | ||||
| Q2 (8.8–13.3) | 0.98 (0.88–1.09) | 0.71 | ||
| Q3 (13.4–18.8) | 1.1 (0.94–1.2) | 0.35 | ||
| Q4 (≥18.9) | 1.0 (0.92–1.2) | 0.58 | ||
| Peritoneum | 1.1 (1.005–1.2) | 0.040 | 1.2 (1.1–1.3) | 0.0013 |
| Upper GI | 0.62 (0.46–1.03) | 0.071 | ||
| Colon | 0.45 (0.15–1.3) | 0.15 | ||
| Lung | 0.88 (0.79–0.99) | 0.027 | 0.93 (0.84–1.04) | 0.19 |
| Pleura | 1.4 (1.008–1.8) | 0.044 | 1.4 (1.08–1.9) | 0.014 |
| Skin/soft tissue | 0.82 (0.65–1.03) | 0.087 | ||
| Wound | 1.3 (1.1–1.4) | 0.0002 | 1.3 (1.2–1.5) | <0.0001 |
| Line | 1.1 (0.98–1.2) | 0.11 | ||
| Fungal infections | ||||
| C. albicans | 1.6 (1.4–1.8) | <0.0001 | 1.7 (1.5–1.8) | <0.0001 |
| C. glabrata | 1.4 (1.2–1.6) | <0.0001 | 1.5 (1.3–1.7) | <0.0001 |
| Gram-negative bacteria | ||||
| E. coli | 0.73 (0.62–0.86) | 0.0001 | 0.77 (0.65–0.90) | 0.0011 |
| E. cloacae | 1.4 (1.2–1.6) | <0.0001 | 1.5 (1.3–1.7) | <0.0001 |
| GP bacteria | ||||
| MSSA | 0.57 (0.45–0.72) | <0.0001 | 0.58 (0.56–0.73) | <0.0001 |
| MRSA | 1.5 (1.3–1.7) | <0.0001 | 1.5 (1.4–1.8) | <0.0001 |
| Coagulase-negative Staphylococcus | 1.4 (1.2–1.7) | 0.0002 | 1.5 (1.2–1.8) | <0.0001 |
| E. faecalis | 1.2 (1.02–1.3) | 0.028 | 1.2 (1.08–1.4) | 0.0025 |
| E. faecium | 1.5 (1.3–1.8) | <0.0001 | 1.6 (1.3–1.9) | <0.0001 |
| VRE | 1.9 (1.7–2.2) | <0.0001 | 2.0 (1.8–2.2) | <0.0001 |
| Anaerobic bacteria | ||||
| C. difficile | 0.42 (0.12–1.4) | 0.17 | ||
| Other organism | 0.53 (0.46–0.62) | <0.0001 | 0.34 (0.46–0.62) | <0.0001 |
Model 1 includes all variables in Tables 1 to 3 that were significantly predictive of inappropriateness (QIC goodness-of-fit statistic = 12442.95).
Model 2 includes all variables in Model 1 that were significantly predictive of inappropriateness (QIC = 12602.46).
The 1.0 referent is taken to be the absence of the variable being analyzed or the lowest quartile (Q1).
To accommodate for a correlated data structure corresponding to multiple episodes of infection per individual, the analysis of inappropriateness among infectious episodes was computed using a GEE approach with robust SEs (i.e., Huber-White sandwich variance estimates).
APACHE, acute physiology and chronic health evaluation; CI, confidence interval; GI, gastrointestinal; MRSA, methicillin-resistant S. Aureus; MSSA, methicillin-sensitive S. aureus; Q1, first quartile; Q2, second quartile; Q3, third quartile; Q4, fourth quartile; RR, relative risk; VRE, vancomycin-resistant enterococcus; WBC, white blood cell count.