Predictive role of neutrophil‐percentage‐to‐albumin, neutrophil‐to‐lymphocyte and eosinophil‐to‐lymphocyte ratios for mortality in patients with COPD: Evidence from NHANES 2011–2018

Abstract Background and Objective This study evaluated the predictive roles of hematologic inflammatory biomarkers including neutrophil‐percentage‐to‐albumin ratio (NPAR), neutrophil‐to‐lymphocyte ratio (NLR) and eosinophil‐to‐lymphocyte ratio (ELR) for mortality in community‐dwelling individuals with chronic obstructive pulmonary disease (COPD). Methods This longitudinal study extracted data of adults 40–79 years who had physician‐diagnosed COPD from the United States (US) National Health and Nutrition Examination Survey (NHANES) 1999–2018. Cox regressions determined the associations between NPAR, NLR, ELR and their components, with all‐cause mortality, cardiovascular disease (CVD) mortality and mortality from chronic lower respiratory disease (CLRD). Receiver operating characteristic (ROC) curve analysis estimated the predictive performances of these biomarkers for 5‐year all‐cause mortality. Results Data of 1158 subjects were analysed. After adjustment, higher NPAR was significantly associated with increased all‐cause and CVD mortality, and mortality from CLRD (adjusted hazard ratio [aHR] = 1.14, 1.15 and 1.16). Higher NLR was associated with an increased all‐cause and CVD mortality (aHR = 1.16 and 1.29). Higher neutrophil was associated with increased all‐cause mortality and mortality from CLRD (aHR = 1.13 and 1.34). Albumin was associated with decreased all‐cause and CVD mortality (aHR = 0.91 and 0.86). ELR, eosinophil or lymphocyte was not significantly associated with either mortality outcomes. Adjusted AUC of NPAR and NLR in predicting 5‐year all‐cause mortality were 0.808 (95% CI: 0.722–0.845) and 0.799 (95% CI: 0.763–0.835), respectively. Conclusion In community‐dwelling US adults with COPD, increased NPAR and NLR are associated with mortality risks. NPAR outperforms the other hematologic inflammatory biomarkers in predicting 5‐year all‐cause mortality.