Association between red blood cell distribution width and long-term mortality in acute respiratory failure patients

The red cell distribution width (RDW) has been reported to be positively correlated with short-term mortality of pulmonary disease in adults. However, it is not clear whether RDW was associated with the long-term prognosis for acute respiratory failure (ARF). Thus, an analysis was conducted to evaluate the association between RDW and 3-year mortality of patients by the Cox regression analysis, generalized additives models, subgroup analysis and Kaplan–Meier analysis. A total of 2999 patients who were first admitted to hospital with ARF were extracted from the Medical Information Mart for Intensive Care III database (MIMIC-III). The Cox regression analysis showed that the high RDW was associated with 3-year mortality (HR 1.10, 95% CI 1.07, 1.12, P < 0.0001) after adjusting for age, gender, ethnicity and even co-morbid conditions. The ROC curve illustrated the AUC of RDW was 0.651 (95% CI 0.631, 0.670) for prediction of 3-year mortality. Therefore, there is an association between the RDW and survival time of 3 years follow-up, particularly a high RDW on admission was associated with an increased risk of long-term mortality in patients with ARF. RDW may provide an alternative indicator to predict the prognosis and disease progression and more it is easy to get.