In multivariate analysis, the RDW was independently associated with five-year mortality (hazard ratio, HR = 1.12; 95% CI 1.01 to 1.24; p = 0.01) after adjusting for age, cardiovascular disease, FEV1, PaCO2, anaemia, C-reactive protein, pulmonary hypertension, and right ventricular dysfunction [27]. Here, CRP is linked to anemia (phenotype).