Preoperative neutrophil-lymphocyte axis and postoperative mortality: an INSPIRE analysis

Systemic inflammation is linked to postoperative outcomes. This study evaluated the association between preoperative neutrophil-lymphocyte axis markers (neutrophil count, lymphocyte count, neutrophil-to-lymphocyte ratio [NLR], and lymphocyte-to-neutrophil ratio [LNR]) and all-cause mortality following abdominal surgery. We conducted a retrospective cohort study using the Informative Surgical Patient dataset for Innovative Research Environment (INSPIRE) database. Associations with mortality were assessed using Cox regression, with results reported as hazard ratios (HR). Survival disparities and dose-response relationships were evaluated via Kaplan-Meier analysis and restricted cubic splines, respectively. Subgroup analyses tested the robustness of findings. Among 7,165 patients (mean age 59.8 ± 13.6 years; 60.7 % male), 1,754 deaths (24.5 %) occurred. After adjustment, higher neutrophil count (HR = 1.03, 95 % CI 1.01-1.05, P = 0.001) and higher NLR (HR = 1.20, 95 % CI 1.11-1.30, P < 0.0001) were associated with increased mortality risk, while higher LNR was associated with lower mortality (HR = 0.67, 95 % CI 0.55-0.82, P < 0.0001). Lymphocyte count showed an inverse trend (HR = 0.93, 95 % CI 0.86-1.00, P = 0.05). Survival probabilities differed significantly across marker quartiles (all P < 0.0001). Dose-response analyses indicated non-linear relationships for LNR and lymphocyte count, but linear associations for NLR and neutrophil count. Subgroup analyses confirmed consistent associations without significant interactions. Preoperative neutrophil-lymphocyte axis markers independently predict mortality in abdominal surgery patients and may aid risk stratification and personalized management.