Table 2.
Univariate and multivariable analysis of factors associated with ICU mortality
| Patients with SA-VAP | Univariate analysis | Multivariable analysis | ||||
|---|---|---|---|---|---|---|
| Alive (n = 90) | Deceased (n = 30) | P value | OR (95% CI) | P value | OR (95% CI) | |
| Demographics | ||||||
| Age, years | 60 [50–68] | 69 [60–71] | 0.01 | 1.04 (1.01–1.08) | 0.11 | 1.04 (0.99–1.09) |
| Male sex, N (%) | 69 (76.7) | 23 (76.7) | 1 | 1 (0.38–2.66) | – | – |
| SAPS II score | 36 [29–39] | 41.5 [36–53] | < 0.01 | 1.07 (1.03–1.11) | < 0.01 | 1.08 (1.03–1.14) |
| Comorbidities | ||||||
| Cardiovascular diseases, N (%) | 12 (13.3) | 8 (26.7) | 0.11 | 2.33 (0.85–6.42) | – | – |
| Diabetes, N (%) | 16 (17.8) | 3 (10.0) | 0.29 | 0.51 (0.14–1.9) | – | – |
| COPD, N (%) | 14 (15.6) | 5 (16.7) | 0.89 | 1.37 (0.49–3.79) | – | – |
| Chronic renal failure, N (%) | 7 (7.8) | 4 (13.3) | 0.38 | 1.82 (0.49–6.73) | – | – |
| Immunosuppression, N (%) | 5 (5.6) | 3 (10.0) | 0.42 | 1.89 (0.42–8.43) | – | – |
| Neoplasm, N (%) | 3 (3.3) | 4 (13.3) | 0.06 | 4.46 (0.94–21.2) | 0.1 | 4.99 (0.76–33) |
| Presenting features and therapy | ||||||
| COVID 19+ , N (%) | 14 (15.6) | 26 (86.7) | 0.08 | 2.15 (0.92–5.04) | 0.83 | 0.86 (0.22–3.44) |
| ICU LOS before VAP, days | 8 [7–11] | 7 [6–14] | 0.21 | 1.01 (0.99–1.04) | – | – |
| MV duration before VAP, days | 6 [6–10] | 5.5 [4–13] | 0.24 | 1.01 (0.99–1.04) | – | – |
| SOFA scorea | 7 [4–8] | 8 [5–10] | 0.06 | 1.15 (0.99–1.33) | 0.99 | 1 (0.81–1.23) |
| Septic shock, N (%)a | 46 (51.1) | 19 (63.3) | 0.24 | 1.65 (0.71–3.86) | – | – |
| AKI requiring CRRT, N (%)a | 9 (10.0) | 3 (10.0) | 1 | 1 (0.25–3.96) | – | – |
| Bacteraemic infection, N (%) | 11 (12.2) | 13 (43.3) | 0.01 | 3.43 (1.33–8.84) | 0.31 | 2.1 (0.51–8.36) |
| Late VAP, N (%) | 63 (70.0) | 23 (76.7) | 0.48 | 1.41 (0.54–3.67) | – | – |
| Methicillin-resistant infection, N (%) | 30 (33.3) | 18 (60.0) | 0.01 | 3 (1.28–7.04) | 0.77 | 0.82 (0.21–3.16) |
| Vancomycin MIC < 1 mcg/mL, N (%) | 47 (52.2) | 14 (46.7) | 0.43 | 1.42 (0.86–2.34) | – | – |
| Linezolid MIC < 2 mcg/mL, N (%) | 20 (22.2) | 9 (30.0) | 0.27 | 1.61 (0.69–3.75) | – | – |
| Vancomycin treatment, N (%) | 17 (18.9) | 4 (13.3) | 0.48 | 0.66 (0.2–2.15) | – | – |
| Linezolid treatment, N (%) | 19 (21.1) | 13 (43.3) | 0.02 | 2.86 (1.18–6.9) | 0.47 | 1.68 (0.41–6.86) |
| Oxacillin treatment, N (%) | 28 (31.1) | 3 (10.0) | 0.01 | 0.25 (0.07–0.88) | 0.06 | 0.14 (0.02–1.06) |
| Other treatments, N (%)b | 25 (27.8) | 11 (36.7) | 0.5 | 1.35 (0.57–3.22) | – | – |
| IIAT, N (%) | 16 (17.8) | 16 (53.3) | < 0.01 | 8.29 (2.15–12.9) | < 0.01 | 4.63 (1.56–13.7) |
Data are presented as median [IQR], unless otherwise indicated
Significant values are in bold (P values < 0.1)
SA Staphylococcus aureus, VAP ventilator-associated pneumonia, OR odds ratio, CI confidence interval, SAPS II Simplified Acute Physiology Score, COPD chronic obstructive pulmonary disease, LOS length of stay, ICU Intensive Care Unit, MV mechanical ventilation, SOFA Sequential Organ Failure Assessment, AKI acute kidney injury, CRRT continuous renal replacement therapy, MIC minimal inhibitory concentration, IIAT Initial Inadequate Antimicrobial Therapy, IQR interquartile range, ROC receiver operating characteristic, AUC area under the curve, SE standard error
We included all variables in the multivariable logistic regression if they reached p ≤ 0.1 on univariate analysis. A stepwise selection procedure was used to select variables for inclusion in the final model. ROC curve analysis was used to assess the goodness of the final logistic regression model (AUC ± SE = 0.85 ± 0.05 with 95%CI 0.77–0.91; chi-square statistics p < 0.001)
aThe day of VAP diagnosis
bAmoxicillin clavulanic-acid (n = 19), quinolones (n = 15), trimethoprim sulphametoxazole (n = 2)