Cox regression analysis of predictors of death in patients aged ≥3 years with Staphylococcus aureus pneumonia, including clinical predictors at admission and microbiological predictors
| Bivariate models | Full model | Best-fitting model | |
| Charlson comorbidity score (per point) | 1.05 (0.91–1.21) | 1.03 (0.85–1.26) | |
| Male sex | 0.68 (0.39–1.17) | 0.95 (0.51–1.78) | |
| PVL | 1.95 (1.12–3.41) | 0.87 (0.42–1.83) | |
| Methicillin resistance | 2.57 (1.41–4.69) | 3.86 (1.34–11.16) | 2.87 (1.53–5.40) |
| SOFA score | 1.11 (1.05–1.16) | 1.03 (0.96–1.11) | |
| Flu-like illness | 0.71 (0.41–1.23) | 0.32 (0.15–0.68) | 0.32 (0.17–0.60) |
| Haemoptysis | 2.62 (1.52–4.52) | 1.87 (0.98–3.54) | 2.15 (1.17–3.93) |
| Rash | 2.17 (1.12–4.23) | 2.59 (1.22–5.48) | 2.52 (1.24–5.12) |
| Leukopenia <3 G·L−1 | 3.45 (2.00–5.97) | 2.38 (1.19–4.76) | 2.38 (1.23–4.58) |
| Procalcitonin per two-fold increase | 1.40 (1.21–1.63) | 1.05 (0.88–1.24) | |
| Lactates per two-fold increase | 2.40 (1.85–3.12) | 2.23 (1.52–3.28) | 2.64 (1.95–3.57) |
| Adapted antimicrobial therapy | 0.82 (0.44–1.53) | 1.54 (0.52–4.59) | |
| Antitoxin therapy | 2.67 (1.48–4.81) | 1.29 (0.63–2.65) |
Data are presented as hazard ratio (95% CI). Bivariate models were independent Cox proportional hazards models, one per predictor. The full multivariable model included all predictors (likelihood ratio test, p<0.001; Akaike information criterion (AIC) 420 with 13 degrees of freedom). The best-fitting model was obtained using a stepwise procedure, starting from the full model, and minimising the AIC (409 with 6 degrees of freedom). Confidence interval widths were not corrected for test multiplicity. PVL: Panton–Valentine leucocidin; SOFA: Sequential Organ Failure Assessment.