Integrating serum ferritin and neutrophil-to-lymphocyte ratio with Sequential Organ Failure Assessment score improves mortality prediction in sepsis

Table 4 Cox proportional analysis

Variable	Unadjusted HR (95%CI)	P value	Adjusted HR (95%CI)1	P value
Ferritin quartiles
Q3 (highest)	Reference	-	Reference	-
Q1 (lowest)	0.58 (0.47-0.73)	< 0.001	0.71 (0.57-0.90)	0.005
Q2 (middle)	0.59 (0.47-0.74)	< 0.001	0.70 (0.55-0.88)	0.002
NLR quartiles
Q3 (highest)	Reference	-	Reference	-
Q1 (lowest)	0.65 (0.52-0.80)	< 0.001	0.73 (0.59-0.91)	0.006
Q2 (middle)	0.60 (0.48-0.74)	< 0.001	0.63 (0.50-0.78)	< 0.001
Combined ferritin & NLR
Both in Q3 (highest)	Reference	-	Reference	-
Both in Q1 (lowest)	0.42 (0.32-0.55)	< 0.001	0.56 (0.42-0.74)	< 0.001
Mixed quartiles	0.65 (0.53-0.80)	< 0.001	0.74 (0.60-0.91)	0.005
Charlson comorbidity index
Per 1-point increase	1.03 (1.00-1.07)	0.048	1.03 (0.99-1.06)	0.161
Age
Per 1-year increase	1.01 (1.01-1.02)	< 0.001	1.02 (1.01-1.02)	< 0.001
Sex
Male	Reference	-	Reference	-
Female	1.08 (0.91-1.29)	0.364	1.11 (0.93-1.32)	0.258
Continuous variables
NLR (per unit)	1.00 (1.00-1.00)	0.072	1.00 (1.00-1.00)	0.908
Ferritin (per unit)	1.00 (1.00-1.00)	< 0.001	1.00 (1.00-1.00)	< 0.001

¹Adjusted model includes sex, age, neutrophil-lymphocyte ratio quartiles, ferritin quartiles, and Charlson comorbidity index.

CI: Confidence interval; HR: Hazard ratio; NLR: Neutrophil-lymphocyte ratio.