Association between red cell distribution width-to-albumin ratio and In-hospital mortality in patients with acute exacerbation of chronic obstructive pulmonary disease and respiratory failure: a retrospective cohort study

This study aimed to investigate the association between the Red cell distribution width-to-albumin ratio (RAR) and in-hospital mortality in patients experiencing Acute Exacerbation of Chronic Obstructive Pulmonary Disease (AECOPD) with concurrent Respiratory Failure (RF). This retrospective study included 594 patients diagnosed with AECOPD and RF at the first affiliated hospital of Jinzhou Medical University, China, between January 2021 and September 2023. The primary outcome measure was in-hospital mortality rate. The participants were categorized into three groups according to RAR tertiles: T1 (2.535–3.871), N = 198; T2 (3.88–4.547), N = 196; and T3 (4.56–11.031), N = 200. Logistic regression and subgroup analyses were performed to investigate the relationship between RAR and AECOPD and RF prognosis in patients. The average age of the participants was 72.1 ± 9.7 years, with 52.2% men ( n = 310). The mean RAR was 4.3 ± 1.0%/g/dL. After adjusting for covariates, the odds ratio for in-hospital mortality per unit increase in RAR was 1.74 [95% Confidence Interval: 1.19–2.55], p = 0.004. A linear relationship was observed between RAR and in-hospital mortality among patients with AECOPD and RF. RAR is an independent risk factor for in-hospital mortality in patients with AECOPD complicated by RF. Elevated RAR levels were associated with increased in-hospital mortality in our patient cohort.