Abstract
BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.