TOPLINE:

Over one third of patients hospitalized with acute exacerbations of chronic obstructive pulmonary disease (COPD) had anemia, which was associated with higher risks for both 1-year readmission and mortality.

METHODOLOGY:

• Researchers conducted a retrospective cohort study to assess the prevalence of anemia and polycythemia in patients admitted with acute exacerbations of COPD and to determine whether these conditions predict risks for 1-year readmission and mortality.
• They included 1525 patients (mean age, 74 years; 56.1% women) in North Denmark who were hospitalized for at least one night in 2018 with acute exacerbations of COPD as the primary diagnosis.
• Patients were classified into three groups on the basis of their hemoglobin level: those with anemia (< 12 g/dL in women and < 13 g/dL in men), normal hemoglobin levels (12-15 g/dL in women and 13-17 g/dL in men), and polycythemia (> 15 g/dL in women and > 17 g/dL in men).

TAKEAWAY:

• Overall, 35.2% of patients had anemia, 58.0% had normal hemoglobin levels, and 6.8% had polycythemia. Men with anemia had significantly longer hospital stays than those with normal hemoglobin levels (P < .001).
• Anemia was associated with a 24% increased risk for 1-year readmission (adjusted hazard ratio [aHR], 1.24; P = .004) and a 60% higher risk for 1-year mortality (aHR, 1.60; P < .001) than normal hemoglobin levels. No such association was observed for polycythemia.
• Patients with anemia had fewer days alive post-discharge than those with normal hemoglobin levels (P for women = .025; P for men = .009); in-hospital or postdischarge mortality did not differ between those with polycythemia and normal hemoglobin levels.

IN PRACTICE:

“Anemia could be used as a predictor of readmission and mortality in subjects with AECOPD [acute exacerbations of chronic obstructive pulmonary disease],” the authors of the study wrote.

SOURCE:

The study was led by Benedicte B.S. Nielsen and Carl-Johan Springborg, Department of Respiratory Diseases, Aalborg University Hospital in Aalborg, Denmark. It was published online on August 23, 2025, in the European Clinical Respiratory Journal.

LIMITATIONS:

This was a retrospective observational study, with some data missing, increasing the risk for bias and confounding. The absence of information on the severity of COPD may have introduced selection bias, as milder cases are often managed in primary care. Additionally, comorbidities — potential confounders — were not differentiated by type or severity.

DISCLOSURES:

The study reported receiving no funding sources, and the authors declared having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.