Abstract
PURPOSE: The neutrophil-to-lymphocyte ratio (NLR) is an inflammatory marker associated with adverse outcomes, including hospital-acquired infections (HAIs) and mortality. This study evaluated its prognostic value in neurosurgical patients. PATIENTS AND METHODS: In this retrospective study of 5474 neurosurgical admissions, 147 HAIs occurred in 93 patients (HAIs group). A control group of 181 patients was matched for age, sex, and mortality status. Clinical (Nutrition Risk Screening 2002 [NRS-2002], Glasgow Coma Scale [GCS]) and demographic variables were compared with NLR. Survival was analyzed using Kaplan-Meier curves. Statistical tests included chi-square, Mann-Whitney, ANOVA, log-rank. RESULTS: Patients with HAIs (58.1% male, mean age 63.7 ± 15.5 years) more often had malnutrition risk (NRS ≥ 3: 65.6% vs 11.0%, p < 0.001) and severe neurological impairment (GCS 3-8: 31.2% vs 8.8%, p < 0.001) than controls. Median length of hospital stay was longer in HAIs (40 vs 5.4 days, p < 0.001). Mean NLR was higher in HAIs (9.25 ± 6.11) than controls (7.99 ± 5.21, p = 0.0001), peaking at 12.78 in patients with central nervous system tumors. An NLR ≥ 17.7 predicted in-hospital mortality with 57.1% sensitivity and 89.4% specificity. In controls, mortality increased significantly above this threshold (χ(2) = 14.83, p = 0.00012), whereas in HAIs the association was not significant. NLR was not linked to hospital stay. CONCLUSION: NLR is a cost-effective marker predicting in-hospital mortality in neurosurgical patients without HAIs, with ≥ 17.7 identifying high-risk cases. Its prognostic value in HAIs is limited and requires multicenter validation.