Introduction: Approximately one-third of patients hospitalised for an exacerbation of chronic obstructive pulmonary disease (COPD) are readmitted to the hospital within 90 days. It is of interest to identify biomarkers that predict relapse in order to prevent readmission in these patients. In our prospective study of patients admitted for COPD exacerbation, we aimed to analyse whether routine haematological parameters can help predict the three-month readmission risk.
Material and methods: 106 patients were included, of whom 23 were female (22%). The age (mean ± SD) was 73 ± 10 years, and the forced expiratory volume in 1 second (FEV1) was 44 ± 15%. The haematological parameters were obtained from the first blood test result during admission. The variables were as follows: red cell distribution width, mean platelet volume (MPV), platelet (PLT) count, neutrophil to lymphocyte ratio, PLT to lymphocyte ratio, MPV to PLT ratio, and eosinophil count. Patients were differentiated into two groups for each haematological parameter according to median value, and the percentage of readmissions in each of the groups was recorded.
Results: Twenty-five patients (24%) were readmitted to hospital within three months of discharge. Only the difference in low-MPV and high-MPV patients was significant (37% vs 10%, p = 0.001). The predictive capacity for three-month readmission measured by the area under the curve (AUC) did not show clinically applicable values; the best result was for MPV (AUC 0.64). In the remaining values, the AUC was between 0.52 and 0.55.
Conclusion: Routine haematological parameters proposed as prognostic biomarkers in COPD obtained at the moment of hospital admission were not useful for predicting three-month readmission.
Keywords: COPD; biomarkers; prognosis; readmission.