Study on the non-linear relationship between neutrophil-to-lymphocyte ratio and prognosis of spontaneous intraventricular hemorrhage

Background The neutrophil-to-lymphocyte ratio (NLR), as an inflammatory marker, has been shown to be associated with the prognosis of various cerebrovascular diseases. However, the specific non-linear relationship between NLR and the prognosis of spontaneous intraventricular hemorrhage (sIVH) remains unclear. This study aimed to investigate the non-linear association between NLR and poor outcomes in sIVH patients. Methods This retrospective study analyzed data from Xiaoshan First People’s Hospital, including all patients hospitalized for sIVH. Blood samples were collected immediately upon hospital admission to calculate NLR, and its relationship with 90-day functional outcomes (defined as poor prognosis with a modified Rankin Scale score ≥4) was evaluated. Results The analysis revealed a J-shaped relationship between NLR and poor outcomes in sIVH patients. As NLR levels increased, the risk of poor outcomes rose, reaching saturation at approximately 8.26. Specifically, when NLR was below 8.26, the odds ratio was 1.49 (95% CI: 1.16–1.91, p = 0.0018); when NLR was above 8.26, the odds ratio was 0.95 (95% CI: 0.84–1.07, p = 0.4194). Multivariate analysis indicated that NLR was an independent predictor of 90-day prognosis in sIVH patients. Conclusion NLR can serve as an important indicator for assessing the prognosis of sIVH patients. The non-linear relationship between NLR and poor outcomes provides new insights for clinical management. Further studies should explore the mechanisms of NLR and its potential applications in sIVH treatment.