Multivariable COX regression analysis for 28-day mortality
| HR | 95% CI | P value | |
| Age (in years) | 1.01 | 1.00 to 1.02 | 0.004 |
| Male sex | 1.05 | 0.89 to 1.24 | 0.554 |
| Respiratory rate | 1.01 | 1.00 to 1.02 | 0.055 |
| Calcium | 0.85 | 0.77 to 0.93 | <0.001 |
| Creatinine >1.2 mg/dL | 0.88 | 0.73 to 1.06 | 0.177 |
| Renal replacement therapy | 0.78 | 0.51 to 1.17 | 0.229 |
| APACHE II score | 1.1 | 1.09 to 1.11 | <0.001 |
| Infection site | |||
| Lung | 1.07 | 0.78 to 1.48 | 0.668 |
| Urogenital | 0.57 | 0.38 to 0.85 | 0.006 |
| Intra-abdominal | 1.29 | 0.93 to 1.81 | 0.132 |
| Group II (normophosphataemia) | Ref | Ref | Ref |
| Group I (hypophosphataemia) | 1.15 | 0.86 to 1.52 | 0.345 |
| Group III (mild hyperphosphataemia | 1.35 | 1.00 to 1.83 | 0.052 |
| Group IV (moderate to severe hyperphosphataemia) | 1.83 | 1.29 to 2.58 | <0.001 |
Group I (hypophosphataemia), phosphate <2 mg/dL; group II (normophosphataemia), phosphate 2–4 mg/dL; Group III (mild hyperphosphataemia), phosphate 4–6 mg/dL; group IV (moderate to severe hyperphosphataemia), phosphate ≥6 mg/dL.
APACHE, Acute Physiology and Chronic Health Evaluation.