Can the Eosinophil-to-Platelet Ratio Predict Chronic Obstructive Pulmonary Disease Exacerbations and Length of Hospital Stay?

Background: An acute exacerbation of chronic obstructive pulmonary disease is a severe condition that escalates the burden on patients and the healthcare system. This study aimed to evaluate the prognostic value of the eosinophil-to-platelet ratio (EPR) in predicting COPD exacerbations and hospital admissions, with these outcomes also assessed as secondary endpoints. Materials and Methods: This cohort study was conducted from 2023 to 2025 at Masih Daneshvari Educational Hospital in Tehran, Iran, among patients with confirmed COPD exacerbation. Participants were assessed during the recovery phase after management of the acute exacerbation. Collected clinical data included the history and frequency of exacerbations in the preceding 12 months; blood test results at discharge; 90-day mortality; hospital readmission; ICU admission; and corticosteroid use within 12 months post-discharge. Data were analyzed using STATA version 17. Results: This study evaluated 249 individuals with COPD exacerbation, with a mean age of 65.66±9.17 years. In individuals with EPR≤1, the risk of experiencing more COPD exacerbations was 17% higher than in those with EPR>1 (adjusted RR=1.17, 95% CI=0.92 -1.49, P=0.195). These results were not statistically significant. In addition, in patients with EPR≤1, the risk of having a higher number of hospitalization days was 16% lower compared to those with EPR>1 (adjusted RR=0.84, 95% CI=0.72-0.98, P=0.036). EPR was not associated with ICU admission and the need for systemic corticosteroids. Conclusion: The association between lower EPR values and a higher number of exacerbations, as well as shorter hospital stays, suggests that EPR could reflect distinct exacerbation phenotypes or patterns of disease activity.