Supplementary Material for: Lymphocyte Cell Ratios and Mortality among Incident Hemodialysis Patients

<b><i>Background:</i></b> Neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been previously suggested as oncologic prognostication markers. These are associated with malnutrition and inflammation, and hence, may provide benefit in predicting mortality among hemodialysis patients. <b><i>Methods:</i></b> Among 108,548 incident hemodialysis patients in a large U.S. dialysis organization (2007–2011), we compared the mortality predictability of NLR and PLR with baseline and time-varying covariate Cox models using the receiver operating characteristic curve (AUROC), net reclassification index (NRI), and adjusted R². <b><i>Results:</i></b> During the median follow-up period of 1.4 years, 28,618 patients died. Median (IQR) NLR and PLR at baseline were 3.64 (2.68–5.00) and 179 (136–248) respectively. NLR was associated with higher mortality, which appeared stronger in the time-varying versus baseline model. PLR exhibited a J-shaped association with mortality in both models. NLR provided better mortality prediction in addition to demographics, comorbidities, and serum albumin; ΔAUROC and NRI for 1-year mortality (95% CI) were 0.010 (0.009–0.012) and 6.4% (5.5–7.3%) respectively. Additionally, adjusted R² (95% CI) for the Cox model increased from 0.269 (0.262–0.276) to 0.283 (0.276–0.290) in the non-time-varying model and from 0.467 (0.461–0.472) to 0.505 (0.500–0.512) in the time-varying model. There was little to no benefit of adding PLR to predict mortality. <b><i>Conclusions:</i></b> High NLR in incident hemodialysis patients predicted mortality, especially in the short-term period. NLR, but not PLR, added modest benefit in predicting mortality along with demographics, comorbidities, and serum albumin, and should be included in prognostication approaches.

**背景：** 中性粒细胞与淋巴细胞比值（Neutrophil-to-lymphocyte ratio, NLR）和血小板与淋巴细胞比值（Platelet-to-lymphocyte ratio, PLR）此前已被提出作为肿瘤预后标志物。二者与营养不良及炎症状态密切相关，因此或可用于预测血液透析患者的死亡风险。
**方法：** 本研究纳入美国某大型透析机构2007—2011年间的108548例新发血液透析患者，采用受试者工作特征曲线下面积（Area Under the Receiver Operating Characteristic Curve, AUROC）、净重新分类指数（Net Reclassification Index, NRI）及调整后R²，对比基线协变量与时变协变量Cox比例风险模型下，NLR与PLR对死亡结局的预测效能。
**结果：** 中位随访时长为1.4年，期间共28618例患者死亡。患者基线时的中位NLR为3.64（四分位间距2.68~5.00），中位PLR为179（四分位间距136~248）。NLR水平升高与死亡风险升高显著相关，且该关联在时变协变量模型中较基线协变量模型更为显著。两种模型均显示PLR与死亡风险呈J型关联。在纳入人口学特征、合并症及血清白蛋白水平的基础上，NLR可进一步提升死亡风险预测效能；其针对1年死亡率的ΔAUROC与NRI（95%置信区间）分别为0.010（0.009~0.012）与6.4%（5.5%~7.3%）。此外，非时变协变量Cox模型的调整后R²（95%置信区间）从0.269（0.262~0.276）提升至0.283（0.276~0.290），时变协变量Cox模型的调整后R²则从0.467（0.461~0.472）提升至0.505（0.500~0.512）。而加入PLR对死亡风险预测无显著增益。
**结论：** 新发血液透析患者的高NLR水平可预测死亡风险，尤其在短期随访中。在纳入人口学特征、合并症及血清白蛋白水平的基础上，NLR可小幅提升死亡风险预测效能，而PLR无此作用，因此NLR应被纳入血液透析患者的预后评估体系。