Neutrophil-lymphocyte ratio: A novel outcome prognosticator following traumatic brain injury: A retrospective analysis

To assess the prognostic significance of Neutrophil-to-Lymphocyte Ratio (NLR) upon presentation in predicting mortality rates and outcomes among patients who sustained moderate to severe traumatic brain injury (TBI) including polytrauma. Single-centre, retrospective study on 478 TBI patients treated between January 2019 to January 2022. Patients with moderate to severe traumatic brain injury admitted within 24 h of injury were included. Patient demographics, clinico-radiological findings, GCS, NLR on admission, Marshall grade on admission, polytrauma, and modified Rankin Score (mRS) at 6 months were analyzed. The outcome measure was dichotomized based on mRS 0–3 as a good outcome and 4–6 as a poor outcome. A statistical analysis was done using a regression model with IBM SPSS V24.0 software. The study group included 434 patients with a mean age of 41.41 ± 17.36 years, ranging from 6 months to 90 years. Besides TBI, 200 (46.08 %) patients had polytrauma. Receiver operating curve (ROC) analysis of NLR for prediction of outcome after 6 months in patients without polytrauma, revealed an NLR cut-off value of >6.24 with an area under the curve (AUC) ± standard error (SE) of 0.717 ± 0.0340 with a corresponding p -value of <0.0001, which correlated with poor outcome. Age, GCS, NLR on admission, and Marshall grade were found to have a significant association with mortality and 6-month mRS in patients with TBI without polytrauma. In cases of moderate to severe Traumatic Brain Injury (TBI) without polytrauma, NLR emerges as a dependable predictor, capable of forecasting both mortality and 6-month modified Rankin Scale (mRS) outcomes. In patients with polytrauma, NLR's reliability for prognostication following TBI is compromised. • NLR, the ratio of neutrophils to lymphocytes in blood, is a cost-effective, non-invasive marker for predicting outcomes. • NLR objectively predicts mortality and 6-month outcomes in moderate to severe TBI patients without polytrauma. • NLR cut-off of 6.4 is predictive of 6-month outcomes in TBI patients.