Abstract
BACKGROUND: Recent studies have identified a co-occurrence of chronic obstructive pulmonary disease and congestive heart failure in ICU patients. Abnormal red cell distribution width (RDW) frequently manifests in critically ill patients, but its clinical significance remains a subject of debate. This study aims to investigate the relationship between RDW and in-hospital mortality in patients with concurrent congestive heart failure and chronic obstructive pulmonary disease. METHODS: We conducted a retrospective cohort study using the Medical Information Mart for Intensive Care (MIMIC) IV version 2.0 database. RDW levels were assessed within 24 h of admission. The impact of RDW at ICU admission on in-hospital mortality was analyzed through multivariable logistic regression models, generalized additive models, and subgroup analysis. RESULTS: We enrolled 6,309 patients with congestive heart failure and concomitant chronic obstructive pulmonary disease, with an in-hospital mortality rate of 12.4% (783/6,309). The fully adjusted model revealed a positive association between RDW and in-hospital mortality in congestive heart failure patients with concurrent chronic obstructive pulmonary disease, even after accounting for confounding factors (OR = 1.07, 95% CI: 1.03-1.12, p < 0.001). When comparing the highest quartile (Q4) to the lowest quartile (Q1), the odds ratio (OR) was 1.62, with a 95% confidence interval (CI) of 1.17-2.22, p = 0.003. We observed a linear relationship between RDW and in-hospital mortality, which remained consistent in subgroup analysis. CONCLUSIONS: Our data suggest that RDW is positively associated with in-hospital mortality in patients with both congestive heart failure and chronic obstructive pulmonary disease. At the same time, large prospective research and longer follow-up time are required to further validate the findings of this study.